Reduced calf muscle pump function is not explained by handgrip strength measurements

OBJECTIVE

Reduced calf muscle pump function (CPF) is an independent risk factor for venous thromboembolism and mortality. We aimed to evaluate the relationship between handgrip strength (HGS) and CPF.

METHODS

Patients referred to the Gonda Vascular Laboratory for noninvasive venous studies were identified and consented. Patients underwent standard venous air plethysmography protocol. CPF (ejection fraction) was measured in each lower extremity of ambulatory patients by comparing refill volume after ankle flexes and passive refill volumes. The cutoff for reduced CPF (rCPF) was defined as an ejection fraction of <45%. Maximum HGS bilaterally was obtained (three trials per hand) using a dynamometer. HGS and CPF were compared (right hand to calf, left hand to calf) and the correlation between the measures was evaluated.

RESULTS

115 patients (mean age, 59.2 ± 17.4 years; 67 females, mean body mass index, 30.83 ± 6.46) were consented and assessed for HGS and CPF. rCPF was observed in 53 right legs (46%) and 67 left legs (58%). CPF was reduced bilaterally in 45 (39%) and unilaterally in 30 (26%) patients. HGS was reduced bilaterally in 74 (64.3%), unilaterally in 23 (20%), and normal in 18 (15.7%) patients. Comparing each hand/calf pair, no significant correlations were seen between HGS and CPF. The Spearman's rank correlation coefficients test yielded values of 0.16 for the right side and 0.10 for the left side.

CONCLUSIONS

There is no significant correlation between HGS and CPF, demonstrating that HGS measurements are not an acceptable surrogate for rCPF, indicating different pathophysiological mechanisms for each process.

Are luggage scales a viable alternative to hand-held dynamometers for the measurement of shoulder scaption strength?

Background

The accurate and reliable measurement of muscle strength is a valuable tool in most medical practices. The use of dynamometers allows for objective muscle strength assessment. Even so, dynamometry has its limitations due to increased cost and inconvenience in the clinic. Isokinetic dynamometers, the gold standard, are typically very large and expensive. However, smaller hand-held dynamometers are a cheaper and more efficient alternative. Hand-held dynamometers have been shown to demonstrate comparable reliability to the more expensive isokinetic dynamometers, despite their reduced cost and ease of use. Even though hand-held dynamometers are cheaper and more convenient to use in the clinical setting, their price tag is still burdensome for most medical practices, commonly costing $1000 or more. The aim of this study is to assess the reliability of luggage scales vs. dynamometers for measuring shoulder scaption strength.

Methods

One hand-held dynamometer was compared to two luggage scales using a set-up intended to mimic clinical testing. The set-up consisted of each device being tethered to the floor with the opposite end tied to a length of paracord that had been placed through a shoulder-height pulley and fastened to a flat plate used to hold the weight. In total, ten trials were completed, where a 2.3 kg (5 lb), 4.5 kg (10 lb), and 11.3 kg (25 lb). weight was measured by each device. Analysis of variance was used to compare the numerical data for the three groups.

Results

Our results indicate that there were no significant differences in the force measurements between each device (P = .99). The average force measurements between the three dynamometers were: 2.3 kg trial: 2.3 kg, 2.4 kg, and 2.2 kg; 4.5 kg trial: 4.5 kg, 4.6 kg, and 4.5 kg ; and 11.3 kg trial: 11.4 kg, 11.3 kg, and 11.4 kg. for the digital dynamometer, digital luggage scale, and the analog luggage scale, respectively. Subgroup analysis showed there was also no difference in force measurements between the 3 devices for the 2.3 kg, 4.5 kg, and 11.3 kg. trials (P = .14, P = .49, and P = .40, respectively).

Conclusion

Our data demonstrates that two inexpensive luggage scales showed no statistically significant differences in measurements compared to an expensive hand-held dynamometer. Utilization of luggage scales to measure shoulder scaption strength should yield similar results to handheld dynamometers. This may be an alternative, objective measure of manual muscle strength that is both efficient and economical.

Reproducibility of peak moment for isometric and isokinetic knee extension exercise

BACKGROUND

Accurate measurements of muscular performance are important for diagnostics, for example during rehabilitation after traumatic injuries but also in competitive sports. For these purposes, dynamometric devices are widely used and considered the gold standard for muscle strength testing. However, few previous studies have tested the reproducibility of peak moment (PM) at velocities close to the maximum device capability, and in general, reproducibility results cannot be transferred to other devices or test protocols. The purpose of this study was to evaluate the reproducibility of PM for different isometric and isokinetic knee extension exercises using the IsoMed 2000.

METHODS

Thirty subjects volunteered in three repeated test sessions, including isometric knee extension (100° and 140° knee angle) and isokinetic knee extension (30°/s and 400°/s). Statistical analysis for comparison of sessions two and three included paired sample t-test, calculation of intraclass correlation coefficient (ICC) and standard error of measurement (SEM). Additionally, Bland Altman statistics and corresponding plots were created.

RESULTS

A significant difference between sessions in PM was found for isometric knee extension in one leg (140° left). Reproducibility was high for all conditions with ICC ranging from 0.964 to 0.988 and SEM in the range of 7.6 to 10.5 Nm. Bland Altman statistics revealed a bias between - 7.3 and 0.7 Nm.

CONCLUSIONS

Reproducibility of PM using the IsoMed 2000 was good after an initial familiarization trial with high values of relative reproducibility. Absolute reproducibility can be interpreted as appropriate for most common practical applications.

Is there hip muscle weakness in adults with chronic non-specific low back pain? A cross-sectional study

BACKGROUND

Patients with chronic low back pain may present changes in hip muscles. However, there is still limited and controversial evidence of the association between hip muscle weakness and chronic low back pain and whether this weakness can be assessed with functional tests. The purpose of this study was to assess whether there is hip muscle weakness in patients with non-specific chronic low back pain and whether there is an association between the positive Trendelenburg and Step-Down tests and hip muscle strength.

METHODS

This cross-sectional study included 40 patients with chronic low back pain and 40 healthy participants, assessed in an outpatient clinic in Vitória, Espírito Santo, Brazil. Muscle strength was measured for the hip abductors, adductors, extensors, internal rotators, and external rotators using isometric manual dynamometry and functional stability was measured by the Trendelenburg and Step-Down tests. Muscle strength was compared using the t test for independent samples and the chi-square test. The association between the tests and strength was performed using a binary logistic regression analysis.

RESULTS

Healthy participants showed a statistically significant greater muscle strength for the right hip abductors (mean difference [MD]: 28.1%, 95% confidence interval [CI]: 9.4 to 46.9), right adductors (MD: 18.7%, 95% CI: 6.2 to 31.2), right internal rotators (MD: 8.7%, 95% CI: 1.5 to 15.8), right extensors (MD: 21.1%, 95% CI: 6.2 to 31.2), left abductors (MD: 30.4%, 95% CI: 11.9 to 49), left adductors (MD: 18.4%, 95% CI: 3.7 to 33.2), and left extensors (MD: 21.6%, 95% CI: 6.6 to 36.5). There was no difference between groups for the positive functional tests, and there was no association between the tests and hip muscle strength.

CONCLUSION

Patients with chronic low back pain tend to have hip abductors, adductors, and extensors weakness. Furthermore, the functional tests should not be associated to hip muscle strength in patients with chronic low back pain.

Comparison between Two Different Handgrip Systems and Protocols on Force Reduction in Handgrip Assessment

INTRODUCTION

Fatigue resistance (FR) can be assessed as the time during which grip strength (GS) drops to 50% of its maximum during a sustained maximal voluntary contraction. For the first time, we compared force-time characteristics during FR test between two different handgrip systems and investigated age- and clinical-related differences in order to verify if a briefer test protocol (i.e., until 75%) could be sufficiently informative.

METHODS

A cohort of young healthy controls (Y, <30 y, 24 ± 3 y, 54% women), middle-aged (MA, 30-65 y, 47 ± 11 y, 54% women), and older (OLD, >65 y, 77 ± 7 y, 50% women) community-dwelling persons, and hospitalized geriatric patients (HOSP, 84 ± 5 y, 50% women) performed the FR test. For this purpose, an adapted vigorimeter (original rubber bulb of the Martin Vigorimeter connected to a Unik 5000 pressure gauge) here defined as "pneumatic handgrip system" (Pneu) and Dynamometer G200 system (original Jamar Dynamometer handle with an in-build strength gauge) here defined as "hydraulic handgrip system" (Hydr) were used. Force-time curves were analysed from 100% to 75% and from 75% to 50% of the initial maximal GS during the FR test. The area under the curve (GW) was calculated by integrating the actual GS at each time interval (i.e., 1/5,000 s) and corrected for body weight (GW/body weight).

RESULTS

For both systems, we found fair associations between FR100-50 and FR100-75 (Pneu mean difference = 50.1 s [95% CI: 47.9-52.4], r2 = 0.48; Hydr mean difference = 28.4 s [95% CI: 27.0-29.7], r2 = 0.52, all p < 0.001) and also moderate associations between GW(100-50)/body weight and GW(100-75)/body weight (Pneu mean difference = 32.1 kPa*s/kg [95% CI: 30.6-33.6], r2 = 0.72; Hydr mean difference = 8.1 kg*s/kg [95% CI: 7.7-8.6], r2 = 0.68, all p < 0.001). Between MA and OLD, we found a significant age-related difference in the GW results in the first 25% strength decay for Pneu (10.2 ± 0.6 kPa*s/kg against 7.1 ± 1.2 kPa*s/kg, respectively).

CONCLUSION

The brief test protocol is valid. Differences within the first 25% strength decay in GW between OLD and HOSP were identified when using Pneu but not when using Hydr. Therefore, a brief FR test protocol using a continuous registration of the strength decay seems to be sufficiently informative in a clinical setting to appraise muscle fatigability, however, only when using a Pneu system.

The influence of vitamin D on handgrip strength in elderly trauma patients

BACKGROUND AND OBJECTIVES

The treatment of elderly patients is an increasing challenge and the long-term sequelae often affect activities of daily living and quality of life in those patients. Handgrip strength (HGS) appears as a promising value to predict the outcome after trauma in elderly patients and to assess the overall muscle strength. Besides the possible role of psychological and hormonal factors, vitamin D may have a positive influence. Furthermore, some data suggest that Vitamin D is beneficial regarding muscle strength and possibly prevents further falls and injuries in orthogeriatric patients. The purpose of this study was to identify if Vitamin D is an influencing factor for HGSin elderly trauma patients.

MATERIALS AND METHODS

94 elderly patients in a Level I Trauma Center aged 60 years or older were prospectively enrolled and HGS as well as serum 25-OH Vitamin D concentration (VDC) were measured. In addition, the standardized questionnaires Barthel Index (BI), Parker Mobility Score (PMS), Short Physical Performance Battery (SPPB), Strength, Assistance with walking, Rise from a chair, Climb stairs and Falls (SARC-F) and European Quality of Life 5 Dimensions 5 Levels Questionnaire (EQ-5D-5L), were used to record mental health status and demographic data.

RESULTS

HGS is mainly related to age and sex in elderly trauma patients. HGS was higher in men (mean_male = 27.31 kg (± 8.11), mean_female = 15.62 kg (± 5.63), p < 0.001 and decreased with age (β_age = - 0.58, p < 0.001). A significant negative correlation between HGS and VDC exists in the overall sample (β_VDC = - 0.27, p_VDC < 0.008), which still remains after adjusting for age (p_VDC < 0.004), but is not significant after adjustment for both main confounders, age and sex (p_VDC < 0.08). Furthermore, the HGS was lower in pateints who reported frequent falls, stumbling, dizziness or a late onset of menopause, and decreased if patients felt anxious or depressed during measurements (β_{anxiety+depression} = - 0.26, p_{anxiety+depression} < 0.01).

CONCLUSIONS

These results do not support the hypothesis that Vitamin D has a positive influence on muscle strength measured by HGS. Nevertheless, this study could confirm the usefulness of HGS as a tool to detect the risk for frequent falls or stumbling. Furthermore, HGS seems to be associated with dizziness and age at onset of menopause. A significant decrease of HGS could also be shown in patients with anxiety and depression. This underlines the importance of interdisciplinary treatment of elderly trauma patients and needs to be taken into account for further studies, as especially the psychological motivation seems to have a significant influence and is sometimes not considered enough in elderly musculo-skeletal patients.

Exhaust emissions of gaseous and particle size-segregated water-soluble organic compounds from diesel-biodiesel blends

This study assessed the emissions of gaseous pollutants and particle size distributed water-soluble organics (WSO) from a diesel vehicle fuelled with ultralow sulphur diesel (B0) and 10 (B10), 20 (B20), and 30% (B30) biodiesel blends in a chassis dynamometer tested under transient mode. Particulate emission sampling was carried out in an ultraviolet (UV) test chamber using a 10-stage impactor. Samples were grouped into three size fractions and analysed by gas chromatography-mass spectrometry. Increasing the biofuel ratio up to 30% in the fuel reduced WSO emissions by 20.9% in comparison with conventional diesel. Organic acids accounted for 82-89% of WSO in all tested fuels. Dicarboxylic acids were the most abundant compound class, followed by hydroxy, aromatic, and linear alkanoic acids. Correlations between compounds demonstrated that adding biodiesel to diesel fuel reduces the emissions of nitrogen oxides (NOx), benzene, toluene, ethylbenzene and xylenes (BTEX), methane (CH4), total and nonmethane hydrocarbons (THC and NMHC), and dicarboxylic and hydroxy acids, but increases emissions of carbon dioxide (CO2) and alkanoic and aromatic acids. Emissions of dicarboxylic and hydroxy acids were strongly correlated with the biodiesel content. WSO emissions of coarse and fine (1.0-10 μm) particles decreased with the increasing biofuel content in fuel blend. The total share of ultrafine (0.18-1.0 μm) and nanoparticles (< 0.18 μm) increased in WSOs emissions from B20 and B30 blends, when compared with petrodiesel. The biodiesel content also affected the chemical profile of WSO size fractions.

Impact of pivoting bite tip on bite force measurement tests

OBJECTIVE

Present a gnathodynamometer design that increases patient comfort, precision, and/or ease for the operator during bite force tests.

MATERIALS AND METHODS

A bite tip capable of pivoting 180° was tested on senior dental students in a double-blind trial. The tests were performed in teeth 11 and 16 with the bite tip on the long axis of the clamp and at an angle of 90° to the clamp. The sample was composed of 24 students, 13 males and 11 females, randomly divided into two groups: the operator group (OP), which was composed of 12 students, 7 males and 5 females, and the test group (TI), which was composed of 12 students, 6 males and 6 females. The operator and participants were asked to evaluate comfort and precision/ease in positioning the bite tip by attributing scores from 0 (total discomfort) to 10 (total comfort) during the test.

RESULTS

No difference was noted in tooth 11 (P > 0.05). In tooth 16, there was a statistically significant improvement (P < 0.01) for the participants tested and the operator using the pivoting bite tip.

CONCLUSIONS

The pivoting bite tip showed no difference in the comfort of the participants and operator precision when testing incisors; however, the tip showed a difference for both conditions in the molar region. The gnathodynamometer geometry showed good results in participant comfort and operator precision when used in bite force tests of the incisors and molars. Further investigations are needed to confirm whether these improvements influence the mean value and maximum bite force measurement.

CLINICAL RELEVANCE

Bite force measurement is a method for obtaining important data to check the functional conditions of the stomatognathic system. With the aging of the world population, it has become important to check the quality of life during aging. The pivoting bite tip improves the comfort and precision of bite tests for the participants tested and for the operator, respectively.

Muscle strength, rate of torque development and neuromuscular activation of the upper arm muscles in children and adolescents with spina bifida

BACKGROUND

The use of locomotive devices requires sufficient levels of upper limb strength. Therefore, it is important to evaluate the maximal isometric torque, rate of torque development and neuromuscular activation in youth with spina bifida. The objective was to investigate these parameters in the elbow muscles of youth with spina bifida versus healthy age-matched peers.

METHODS

Forty-eight participants (8-17 years) were recruited: Spina Bifida (n = 23) and non-affected Controls (n = 25). Maximal isometric elbow flexor/extensor contractions were performed to assess maximal muscle strength (peak torque) and rate of torque development, along with synchronized electromyography recording in the biceps and triceps brachii muscles.

FINDINGS

During elbow flexor contractions, Spina Bifida showed reduced rate of torque development in the early contraction phase (0-50 ms) along with lowered relative rate of torque development in the later rate of torque development phase (0-100/200/300 ms) compared to controls. Spina Bifida showed reduced rate of torque development for the elbow extensors in the later phase of rising muscle force (0-200/300 ms) compared to controls. Lower isometric peak torque and smaller triceps brachii electromyography amplitudes (0-200/300 ms) were observed during elbow extensor contractions in Ambulatory spina bifida participants vs. controls.

INTERPRETATION

Although a majority of peak torque and rate of torque development parameters did not differ, significant impairments in maximal and rapid elbow muscle force characteristics were noted in Spina Bifida compared to non-affected Controls. Ambulatory and Non-ambulatory spina bifida participants demonstrated similar rate of torque development in their upper arm muscles.

Psoas weakness following oblique lateral interbody fusion surgery: a prospective observational study with an isokinetic dynamometer

BACKGROUND CONTEXT

Although the surgical corridor used for oblique lateral interbody fusion (OLIF) protects the intrapsoas nerves by causing minimal compression, transient weakness remains the most commonly reported postoperative complication.

PURPOSE

Using a dynamometer to evaluate how the hip flexor strength changes following OLIF.

STUDY DESIGN/SETTING

A prospective observational study.

PATIENT SAMPLE

Forty-six patients who underwent single or multi-level OLIF for lumbar spondylolisthesis.

OUTCOME MEASURES

Isokinetic dynamometer values (peak torque, total work, average power), visual analogue scale (VAS) scores for leg pain, hypoesthesia, subjective weakness of the left hip flexor muscle, Oswestry disability index, body mass index, bone mineral density, radiologic findings of the psoas muscle (cross-sectional area, Hounsfield unit (HU), fat portion grade), and psoas retraction time.

METHODS

The isokinetic muscle strength of the hip flexor was measured five times (preoperatively and postoperatively at 2 days, 1 week, 1 month, and 3 months) for both legs. The peak torque was defined as the postoperative strength of the left hip flexor muscles, and was compared to the preoperative baseline value. The strength of the left and right hip flexor muscles were also compared at each time point. For logistic regression analysis, when the peak torque was below the median value, it was defined as lower peak torque.

RESULTS

Up to 1 week after surgery, the strength of the left hip flexor muscle decreased significantly (paired difference in peak torque was 22.6%, p<.001). In the results of multivariate logistic regression analysis, diabetes (odds ratio [OR]=8.43, p=.020) and the HU of the psoas muscle (OR=0.916, p=.034) were associated with lower peak torque 1 week after surgery. From 1 month after surgery, postoperative weakness of the psoas muscle was not significant. In the questionnaire survey, subjective left hip flexion weakness was reported in 8.5% (4/47) of patients 1 week after surgery, and it remained in only 2.1% (1/47) of patients after 3 months of operation. The frequency of left anterior thigh pain and hypoesthesia decreased from 85.1% (40/47) at 1 week to 2.1% (1/47) at 3 months after surgery. The mean VAS score for left anterior thigh or groin pain decreased significantly at 1 month after surgery (PO2D: 4.04±1.84, PO1M: 1.67±1.10, p<.001).

CONCLUSIONS

Dynamometer measurement showed that psoas strength declined significantly up to 1 week after OLIF surgery. Patients with diabetes or lower HU of the psoas muscle showed delayed recovery from postoperative weakness of the psoas muscle. However, the weakness was insignificant from 1 month after surgery. At 3 months after surgery, the other psoas-related problems (left anterior thigh pain and hypoesthesia) also disappeared.

Alternative instrument for the evaluation of handgrip strength in Duchenne muscular dystrophy

Background

The commonly used dynamometers can be ineffective in evaluating handgrip in patients with Duchenne muscular dystrophy (DMD), especially children with generalized muscle weakness. The aim of this study was to analyze whether the modified sphygmomanometer is an effective instrument for handgrip strength evaluation in patients with DMD, during different stages of the disease.

Method

The handgrip strength of 33 patients was evaluated by the Jamar dynamometer and the modified sphygmomanometer. Motor function was evaluated by the Motor Function Measurement (MFM) scale. Four evaluations, with a six-month interval between each, were performed: Evaluation 1 (N = 33), Evaluation 2 (N = 24), Evaluation 3 (N = 15), and Evaluation 4 (N = 8). A linear regression model with mixed effects was used for the longitudinal data and descriptive analysis of strength for all four evaluations.

Result

The first evaluation data presented very high correlations between the dynamometer and the modified sphygmomanometer (r = 0.977; p < 0.001). The longitudinal analysis showed a significant difference between Evaluation 1 and the other handgrip strength evaluations obtained using the dynamometer (p < 0.05) but not the modified sphygmomanometer (p > 0.05). Null values were obtained only when using the dynamometer device.

Conclusion

The modified sphygmomanometer seems to be more suitable than the dynamometer for measuring handgrip strength in all stages of DMD.

Single versus double plating for bicondylar tibia plateau fractures: Comparison of range of motion, muscle strength, clinical outcomes and accelerometer-measured physical activity levels

BACKGROUND

Optimal treatment of bicondylar plateau fractures is still a matter of debate. Accelerometer-measured physical activity levels may help us to obtain objective information regarding the quality of life of patients. The aim of this study was to compare the physical activity levels, objective and subjective functional results and stabilities of fixations of patients with treated bicondylar plateau fractures.

METHODS

In this cross-sectional study of 23 patients, accelerometer-measured physical activity levels, daily energy consumption and measurements of knee joint range of motion (ROM) and muscle strength were measured. While Knee Injury and Osteoarthritis Outcome Score (KOOS) was used as a patient-reported outcome measurement, Rasmussen Radiological Score was used for radiological evaluation.

RESULTS

There was no significant difference between the groups in terms of physical activity levels and daily energy consumption (P = 0.667). While Total KOOS, Symptom and Stiffness and Sports Activities scores were higher in patients with a single plate (P = 0.034, P = 0.003 and P = 0.014, respectively), knee flexion and extension ROM and flexor and extensor muscle strength were similar between groups (P = 0.405, P = 0.095, P = 0.982 and P = 0.988, respectively).

CONCLUSIONS

While patient-reported outcome measurements were better with single plating, there was no difference between the groups in terms of physical activity levels, ROM, muscle strength and radiological results. Although it should be kept in mind that the choice of the primary surgeon, the condition of the soft tissue and the fracture geometry are also effective in the decision-making process, single plating seems to be a valid surgical option in the treatment of bicondylar plateau fractures.

Grip strength is more sensitive to changes in elbow position than isolated wrist extension strength in patients with lateral elbow tendinopathy

STUDY DESIGN

This is an observational study.

INTRODUCTION

Because isometric wrist extension minimizes the effects of other muscles, the sensitivity of wrist extension strength testing on patients with lateral elbow tendinopathy (LET) should be evaluated.

PURPOSE OF THE STUDY

The purpose of the study was to compare the effects of the elbow position on wrist extension and grip strength in patients with LET.

METHODS

Patients were screened for at least 2 of 5 clinical tests for LET. Between-day intraclass correlation coefficients (ICC_{3, 1}) for healthy individuals were examined for both grip and wrist extension strength at 0° and 90°. To compare the effects of elbow position on wrist extension strength to grip strength, a repeated measure analysis of variance was run using 2 within-group factors, test angles (0° and 90°), and the test type (wrist extension and grip).

RESULTS

Nineteen patients with LET and twenty-one healthy participants were included. The between-day intrarater reliability for both wrist extension and grip strength was excellent for the healthy subjects across the 0° and 90° positions (ICC > .95). The analysis of variance yielded a significant interaction between the type of test and the angle of testing (P = .00).

DISCUSSION

Both wrist extension strength and grip strength are reliable between-day measures. For patients with LET, there was a significant decrease in grip strength when testing at 0° compared with 90°.

CONCLUSION

In patients with LET, clinicians can expect wrist extension strength at 0° and 90° to be similar. Grip strength testing may be a more relevant clinical test at the initial evaluation.

Training muscle activation patterns of the lower paretic extremity using directional exertion improves mobility in persons with hemiparesis: a pilot study

Background

Controlled static exertion performed in the sagittal plane on a transducer attached to the foot requires coordinated moments of force of the lower extremity. Some exertions and plantarflexion recruit muscular activation patterns similar to synergies previously identified during gait. It is currently unknown if persons with hemiparesis following stroke demonstrate similar muscular patterns, and if force feedback training utilizing static exertion results in improved mobility in this population.

Methods

Electromyographic (EMG) activity of eight muscles of the lower limb were recorded using surface electrodes in healthy participants (n = 10) and in persons with hemiparesis (n = 8) during an exertion exercise (task) performed in eight directions in the sagittal plane of the foot and a plantarflexion exercise performed at 20 and 40% maximum voluntary effort (MVE). Muscle activation patterns identified during these exertion exercises were compared between groups and to synergies reported in the literature during healthy gait using cosine similarities (CS). Functional mobility was assessed in four participants with hemiparesis using GAITRite® and the Timed Up and Go (TUG) test at each session before, during and after static force feedback training. Tau statistics were used to evaluate the effect on mobility before and after training. Measures of MVE and the accuracy of directional exertion were compared before and after training using ANOVAs. Spearman Rho correlations were also calculated between changes in these parameters and changes in mobility before and after the training.

Results

Muscle activation patterns during directional exertion and plantarflexion were similar for both groups of participants (CS varying from 0.845 to 0.977). Muscular patterns for some of the directional and plantarflexion were also similar to synergies recruited during gait (CS varying from 0.847 to 0.951). Directional exertion training in hemiparetic subjects resulted in improvement in MVE (p < 0.040) and task performance accuracy (p < 0.001). Hemiparetic subjects also demonstrated significant improvements in gait velocity (p < 0.032) and in the TUG test (p < 0.022) following training. Improvements in certain directional efforts were correlated with changes in gait velocity (p = 0.001).

Conclusion

Static force feedback training following stroke improves strength and coordination of the lower extremity while recruiting synergies reported during gait and is associated with improved mobility.

Effects of autogenic and reciprocal inhibition muscle energy techniques on isometric muscle strength in neck pain: A randomized controlled trial

BACKGROUND

Neck is one of the most common sites of musculoskeletal symptoms, and muscle shortening and weakness is observed to be a common cause of neck pain and disability.

OBJECTIVE

To compare the immediate and short term effects of static stretching (SS), autogenic inhibition (AI) and reciprocal inhibition (RI) muscle energy techniques (MET) on isometric muscle strength in the management of mechanical neck pain.

METHODS

A randomized controlled trial was conducted on 78 participants with neck pain randomly allocated to SS, AI-MET and RI-MET groups. All the participants received Trans Cutaneous Electrical Nerve Stimulation (TENS), hot pack and unilateral postero-anterior glide, followed by 3-5 repetitions of either SS, AI-MET or RI-MET for five consecutive sessions. Numeric pain rating scale (NPRS) and Modified Sphygmomanometer Dynamometry (MSD) were used as outcome measurement tools. One way ANOVA and repeated measures ANOVA were used for inter-group and intra-group comparison.

RESULT

In terms of MSD scores, a significant difference (p< 0.05) was observed between the groups. Both AI-MET and RI-MET were found to be comparatively more effective than SS, however AI-MET was found to be the most effective.

CONCLUSION

AI-MET is more effective than SS and RI-MET in terms of improving isometric muscle strength in patients with mechanical neck pain.

Test-retest reliability of a functional electromechanical dynamometer on swing eccentric hamstring exercise measures in soccer players

Background

The use of a functional electromechanical dynamometer (FEMD) has been proposed as a valid and effective tool to evaluate specific movement patterns. The aim of this study was to determine the reliability of FEMD on swing eccentric hamstring exercise (SEHE) measures in soccer players.

Methods

Nineteen federated male soccer players (20.74 ± 4.04 years) performed the SEHE at three different isokinetic velocities (20–40–60 cm/s). These evaluations were conducted in four sessions, two for familiarization and two for registration. The average and maximum load (N) of the three isokinetic velocities was calculated from the values obtained from the FEMD (Dynasystem^®, Bangalore).

Results

The main results of this research showed that the reliability was high for the average load in the condition of 40 cm/s, presenting the highest ICC value (0.94). For maximum load, reliability was high in the condition of 20 cm/s. The manifestation of the most reliable load was the maximum load (ICC = 0.91–0.87).

Conclusions

FEMD (Dynasystem^®, Bangalore) is a reliable device to evaluate the eccentric strength of the hamstring muscles in soccer players.

The influence of photobiomodulation on the temperature of the brachial biceps during muscle fatigue protocol

Physical activity raises body temperature. However, the literature does not contain studies about whether the employment of hotobiomodulation (PMB) could significantly influence body temperature during a muscle fatigue (MF) protocol. Thus, the aim of this study was to evaluate the effects of PMB on the temperature of the biceps brachii muscle during the performance of a muscle fatigue protocol. The study consisted of 14 volunteers who were divided into two groups (placebo group and laser group) and all individuals rotated into all groups (crossover study). To induce muscle fatigue, three maximum voluntary isometric contractions (MVIC) were performed for 50 s with a 50-s interval. During the MVIC, the muscle strength was assessed using surface electromyography and infrared temperature at 0, 5, 10, and 15 min after the tests. The laser group presented a less accentuated decrease in muscle strength, evidencing a lower rate of muscle fatigue (p > 0.05) in relation to the other groups. In the temperature analysis, the control group exhibited the highest average temperature, with a significant difference only for the placebo. The results indicate that the control displayed the greatest physical degeneration and the PMB group had a positive effect on MF attenuation and body thermoregulation.

Reliability of hip muscle strength measured in principal and intermediate planes of movement

BACKGROUND

Muscle strength testing is widely used in clinical and athletic populations. Commercially available dynamometers are designed to assess strength in three principal planes (sagittal, transverse, frontal). However, the anatomy of the hip suggests muscles may only be recruited submaximally during tasks performed in these principal planes.

OBJECTIVE

To evaluate the inter-session reliability of maximal isometric hip strength in the principal planes and three intermediate planes.

METHODS

Twenty participants (26.1 ± 2.7 years, 50% female) attended two testing sessions 6.2 ± 1.8 days apart. Participants completed 3-5 maximal voluntary isometric contractions for hip abduction, adduction, flexion, extension, and internal and external rotation measured using a fixed uniaxial load cell (custom rig) and commercial dynamometer (Biodex). Three intermediate hip actions were also tested using the custom rig: extension with abduction, extension with external rotation, and extension with both abduction and external rotation.

RESULTS

Moderate-to-excellent intraclass correlation coefficients were observed for all principal and intermediate muscle actions using the custom rig (0.72-0.95) and the Biodex (0.85-0.95). The minimum detectable change was also similar between devices (custom rig = 11-31%; Biodex = 9-20%). Bland-Altman analysis revealed poor agreement between devices (range between upper and lower limits of agreement = 77-131%).

CONCLUSIONS

Although the custom rig and Biodex showed similar reliability, both devices may lack the sensitivity to detect small changes in hip strength commonly observed following intervention.

Handgrip strength: Normative reference values in males and females aged 6-64 Years old in a Colombian population

BACKGROUND

Handgrip strength (HGS) is an indicator of overall strength; therefore, individual HGS measurements should be interpreted using geographic region and ethnic group references.

AIMS

The aim of this study was to develop new normative values for absolute and relative HGS in the Colombian population after stratification by sex, age, and body mass using the large National Representative Nutrition Survey 2015.

METHODS

This cross-sectional study included 3803 subjects aged 6-64 years. Absolute HGS was measured using a hand dynamometer with an adjustable grip, and normalized HGS was calculated by dividing the HGS by body mass. Smoothed centile tables for the P3, P10, P25, P50, P75, P90, and P97 centiles were calculated using Cole's lambda-mu-sigma (LMS) method. This study used a cutoff at 2 standard deviations (SDs) below the sex-specific peak mean value across the life course to define weak, absolute and relative HGS.

RESULTS

In men, HGS peaked at 26-33 years of age (~43.0 kg in P50), especially in the upper centiles, and fell away quickly. The pattern was different in females, where this value peaked at ages 25-33 (~26.0 kg in P50). We found a curvilinear pattern for HGS that declined with age in both sexes. There was significant variation in the slope for HGS in men and women around the age of 25 and 35 years, respectively.

CONCLUSION

The normative values presented here are a valuable source of information for the clinical assessment of HGS and for comparison with studies from other countries.

Prospective randomized clinical trial of open operative, minimally invasive and conservative treatments of acute Achilles tendon tear

INTRODUCTION

The acute Achilles tendon rupture (AATR) is a common injury of great importance in an increasingly active society. When early functional treatment is established, recent literature shows comparable rates of re-rupture in conservative and surgical treatments of AATR. However, there is no study comparing the outcome using a dynamometer. The aim of this study is to evaluate the results of patients with AATR treated conservatively and surgically using a dynamometer. In addition, the data are compared to evaluation of the Achilles tendon with ultrasound.

MATERIALS AND METHODS

Between 2012 and 2015, 90 patients (mean age 41 years, male-to-female ratio 81:9) with AATR were enrolled in a prospective, randomized, and monocentric study. Thirty patients were assigned to each of the three different treatment groups. Group OPEN received a conventional open suture of the Achilles tendon, group MIN received a minimally invasive suture and patients in group CONS were treated conservatively. Follow-up treatment was the same for all patients regardless of the group they were assigned to. Plantar flexion force was assessed using a dynamometer (Biodex® System 3 Pro, Biodex Medical Systems). Further evaluation included a physical test and ultrasound of the Achilles tendon.

RESULTS

Sixty-nine patients were available for a 24-month follow-up. In each of the OPEN and MIN groups, there was one re-rupture. In the CONS group, there were two re-ruptures. A positive correlation between the Biodex® dynamometer measurement and the American Orthopaedic Foot and Ankle Society Ankle-Hindfoot Score (AOFAS-AH) could be found in all groups. Nevertheless, there were no significant differences between the treatment groups after 2 years. On sonography, all patients showed isolated structure loosening and a significantly thickened cross-sectional area compared with the non-injured opposite side, without differences between the groups. There was no correlation between the Biodex® measurement and sonographic outcome.

CONCLUSION

At 24-month follow-up, no significant difference can be found in patients with AATR treated operatively or conservatively. It is, therefore, important to inform patients with AATR regarding the respective advantages and disadvantages of the individual treatment strategies.

LEVEL OF EVIDENCE

Randomized controlled trial; level 1.

Effects of resistance training interventions on muscular strength in adults with intellectual disability: a systematic review and meta-analysis

PURPOSE

Muscular strength is critical for adults with an intellectual disability (ID) to promote their mobility, cardiovascular capacity, and performance of daily living/recreational/vocational activities. This article reports the results of the first systematic review and meta-analysis of peer-reviewed clinical trials that evaluated the effects of resistance training (RT) interventions on muscular strength in adults with ID.

METHODS

The protocol was registered with PROSPERO (CRD42020184905). The review focuses on clinical trials that recorded quantitative measures of maximum muscular strength. Eleven electronic databases were searched from their earliest available record up to May 2020. After screening 1996 search records, 11 clinical trials were reviewed.

RESULTS

The RT interventions, while heterogeneous, had an overall significant (p ≤ 0.05) effect on muscular strength in adults with ID, ages 25-58 years. The findings were more significant and less heterogeneous for non-combined RT interventions than for interventions that combined RT exercises with aerobic or balance exercises. The TESTEX overall score was 8.3 ± 3.6.

CONCLUSIONS

RT interventions (particularly when not combined with other exercises) are effective in promoting muscular strength in adults with ID. The limited number of studies and the low study quality scores indicate a potential risk of bias, which limits the interpretation of the findings and warrants further investigation.IMPLICATIONS FOR REHABILITATIONMuscular strength is critical for adults with an intellectual disability (ID) to promote their mobility, cardiovascular capacity, and performance of daily living/recreational/vocational activities.RT interventions are an effective means of improving muscular strength in adults with ID, especially when not combined with other forms of exercise.Testing and assessment protocols used in RT programs should be individualized for adults with ID to accommodate their characteristics and should be implemented under conditions similar to those experienced during the training regimen.It is important to implement familiarization sessions before carrying out muscular strength testing or initiating an RT program to ensure safety, accuracy, and effectiveness of the program for adults with ID.

Preoperative and postoperative shoulder position sense in patients who underwent arthroscopic Bankart repair for traumatic shoulder joint instability

Background

Proprioceptive feedback is a reflex dislocation prevention mechanism that contributes to shoulder joint stability. In patients with Bankart lesions, the anteroinferior glenohumeral ligament complex is damaged and reduces the likelihood of tensile stress. As a result, proprioceptive feedback does not work, which leads to instability. Surgical reconstruction is indicated to restore proprioception, but the details of recovery after arthroscopic surgery are unknown. The purpose of this study is to investigate whether arthroscopic Bankart repair can improve the position sense of the shoulder.

Methods

We used the isokinetic dynamometer Biodex System 3 (Biodex, Shirley, NY, USA) to investigate preoperative and postoperative joint position sense in 140 shoulders (137 men, 3 women) undergoing arthroscopic Bankart repair for traumatic shoulder joint instability. The control subjects comprised 40 shoulders of healthy volunteers (all men). Active position sense was measured by setting the shoulder external rotation to 75° based on 90° abduction and neutral internal/external rotation position. Reproductive angle inaccuracy (RAI) was measured thrice, and the mean value was calculated. The RAI was measured preoperatively, 6 months and 1 year postoperatively, and at the final observation (range, 16-96 months; mean, 31.5 months).

Results

Mean RAI was significantly higher (6.4°) preoperatively in the traumatic shoulder instability group than in the control group (5.0°). Mean postoperative RAI changed to 5.0, 4.9, and 4.7° at 6 months, 1 year, and final observation, respectively (mean, 31.5 months). RAI recovered to the same level as the control group at 6 months after the surgery and was maintained the same level until final observation.

Conclusion

Position sense was significantly worse in patients with traumatic shoulder joint instability than in healthy volunteers, and a significant improvement in position sense was observed after reconstruction of the anteroinferior glenohumeral ligament complex by arthroscopic Bankart repair. Therefore, arthroscopic Bankart repair is a favorable procedure that can improve the position sense of the shoulder in patients with traumatic shoulder instability.

Knee Extensor Strength Measurement in Patients With Limited Physical Activity Using a Supine Dynamometer Anchoring Frame

OBJECTIVE

To investigate the reliability of knee extensor strength measurements using a supine hand-held dynamometer (HHD) anchoring frame in patients with limited physical activity. Although an HHD is suitable for bedside use, its inter-rater reliability is low because measurements can be influenced by tester strength.

METHODS

Maximal knee extensor isometric strength was measured using an HHD anchored to the supine frame. Three trials of three maximal contractions were assessed by two raters.

RESULTS

A total of 33 inpatients who were non-ambulatory due to acute illness participated in the study. The intraclass correlation coefficients were 0.974 (inter-rater) and 0.959 (intra-rater). The minimal detectable changes in intra- and inter-observer measurements were 29.46 N (24.10%) and 36.73 N (29.26%), respectively. The limits of agreement ranged from -19.79% to 24.81% for intra-rater agreement and from -21.45% to 37.07% for inter-rater agreement.

CONCLUSION

The portable dynamometer anchoring system can measure the isometric strength of the knee extensor reliably in the supine position, and could be used for measurements in patients who have difficulty visiting the laboratory and maintaining a seated posture.

Utility of peak torque and rate of torque development characteristics to identify walking performance ability in older women

OBJECTIVES

It is unclear whether peak torque and rate of torque development (RTD) measurements can characterize functional differences in older adults according to their performance on a six-minute walk test. This study aimed to examine the efficacy of isometric peak torque and RTD characteristics of the knee extensors to differentiate between functional status in older women who are able (higher functioning) versus those who are unable (lower functioning) to walk 550 m in six minutes.

METHODS

Ten higher functioning (67±4 years) and 10 lower functioning (68±4 years) older women performed three isometric knee extension maximal voluntary contractions followed by a six-minute walk test. Peak torque and early (RTD100), late (RTD200), and maximum (Peak RTD) RTD measurements were obtained from each contraction.

RESULTS

The higher functioning group exhibited greater peak torque, Peak RTD, RTD100, and RTD200 compared to the lower functioning group (P≤0.011), with larger differences occurring for RTD characteristics (39.9-54.9%) than peak torque (20.3%). Multiple regression analysis indicated that RTD200 was the single best predictor of the distance covered during the six-minute walk test (R2=0.437, P=0.002).

CONCLUSIONS

These findings suggest that knee extensor muscle strength, and in particular RTD, may be an effective discriminator and predictor of walking performance ability in older women.

External rotator strength deficits in non-athletic people with rotator cuff related shoulder pain are not associated with pain intensity or disability levels

BACKGROUND

Strength deficits are often reported in people with rotator cuff related shoulder pain. However, these have mainly been tested in athletic populations and pain interference with testing has not been considered.

OBJECTIVES

To examine strength without pain interference in non-athletic people with rotator cuff related shoulder pain and its association with pain intensity and disability.

DESIGN

Cross-sectional study.

METHODS

Sixty-seven participants with rotator cuff related shoulder pain were assessed for isometric strength of shoulder external rotator and internal rotator muscles without pain interference with a hand-held dynamometer. Strength was normalized (%body weight). Differences in external and internal rotation strength and external:internal rotator strength ratio between symptomatic and asymptomatic sides were examined (Independent t-tests, Wilcoxon rank sum tests). Spearman's rank correlation coefficients were used to examine associations between strength and pain and disability levels.

RESULTS

There was no significant difference in internal rotator strength normalized to body weight between symptomatic and asymptomatic sides. There was a significant difference in external rotator strength normalized to body weight (p < .001) and external:internal ratio (p < .001) between sides. No significant correlations were found between strength and pain or disability levels.

CONCLUSION

Non-athletic people with rotator cuff related shoulder pain had external rotator strength deficits without pain interference during strength testing, which were not associated with pain and disability levels.

Normative reference values on handgrip strength among healthy adults of Dhulikhel, Nepal: A cross-sectional study

Context

Handgrip strength (HGS) is the amount of static force that the hand can generate around the dynamometer and can be defined as the ability of the hand to hold the objects between the thumb and fingers. Handgrip measurement is simple but also a valid measure of overall muscle strength and also provides an objective index of functional integrity of upper extremity.

Aims

To provide population-based HGS reference values for Nepalese adults from 19 to 70 years of age.

Settings and Design

A cross-sectional study was conducted in Dhulikhel community among 526 participants.

Methods and Materials

Jamar Dynamometer was used for measuring HGS based on the recommendation provided by the American Society of Hand Therapists.

Statistical Analysis Used

Data were analyzed using STATA version 14.

Results

Men exhibited higher HGS compared to women with maximum grip strength observed in age group of 19-29 which were 47.24 kg and 32.51 kg for men and women, respectively. HGS decreases with increasing age in both dominant and nondominant hands.

Conclusions

The normative reference values provided in this study may serve as a guide for interpreting grip-strength measurements obtained from tested individuals.

Force direction and arm position affect contribution of clavicular and sternal parts of pectoralis major muscle during muscle strength testing

STUDY DESIGN

Cross-sectional study.

PURPOSE OF THE STUDY

The study aims to determine the effects of force direction and arm position in differentiating the clavicular (PMc) and sternal (PMs) parts of the pectoralis major (PM) muscle during maximal voluntary isometric contraction (MVIC) to provide basic evidence to support the clinical thinking behind muscle strength testing of PM.

METHODS

Nine experimental conditions with 3 force directions of horizontal adduction (+30° oblique, horizontal, and -30° oblique to the transverse plane) and 3 arm rotation positions (0°, 45°, and 90° shoulder external rotation from the transverse plane) were randomly tested for 26 healthy male participants. The MVIC force level was monitored and measured with a fixed dynamometer, and the surface electromyographic (EMG) signals of the PMc, PMs, anterior deltoid, middle deltoid, and latissimus dorsi were collected during the test for each condition. The PMc/PMs EMG ratio and normalized EMG amplitude were used to quantify the contribution of the tested muscles.

RESULTS

The MVIC force level significantly declined when the arm's external rotation increased (P < .01; the grand mean decreased from 106.7 N ± 27.8 N to 89.5 N ± 22.6 N). The PMc/PMs EMG ratio showed that the best test condition to differentiate the PMc and PMs was the force direction of +30° oblique to the transverse plane and the 45° arm rotation position. Other muscles contributed less than 40% of their MVIC activity levels, with a higher activation level found in the anterior deltoid muscle (P < .01).

CONCLUSIONS

Arm rotation position should be considered as a predominant factor when clinically examining the strength of horizontal adduction movement. All tested conditions failed to fully separate PMc and PMs activation during MVIC and suggested that functional differentiation of the PM might not be applicable to maximal exertion.

LEVEL OF EVIDENCE

NA.

Muscle structure governs joint function: linking natural variation in medial gastrocnemius structure with isokinetic plantar flexor function

Despite the robust findings linking plantar flexor muscle structure to gross function within athletes, the elderly and patients following Achilles tendon ruptures, the link between natural variation in plantar flexor structure and function in healthy adults is unclear. In this study, we determined the relationship between medial gastrocnemius structure and peak torque and total work about the ankle during maximal effort contractions. We measured resting fascicle length and pennation angle using ultrasound in healthy adults (N=12). Subjects performed maximal effort isometric and isokinetic contractions on a dynamometer. We found that longer fascicles were positively correlated with higher peak torque and total work (R²>0.41, P<0.013) across all isokinetic velocities, ranging from slow (30°/s) to fast (210°/s) contractions. Higher pennation angles were negatively correlated with peak torque and total work (R²>0.296, P<0.067). These correlations were not significant in isometric conditions. We further explored this relationship using a simple computational model to simulate isokinetic contractions. These simulations confirmed that longer fascicle lengths generate more joint torque and work throughout a greater range of motion. This study provides evidence that ankle function is strongly influenced by muscle structure in healthy adults.

Summary: Using ultrasound measurements of muscle structure and dynamometer measurements of ankle function, we found that longer muscle fascicles positively correlated with increased ankle kinetics.

Pilates versus resistance training on trunk strength and balance adaptations in older women: a randomized controlled trial

Background

The neuromuscular decline impact in the functional independence of older women is determining the necessity of implementing new strategies focused on core strength training and postural stability maintenance to promote healthy aging.

Objectives

To define whether Pilates or resistance training is better at improving (a) core isometric and isokinetic muscular strength, and (b) static and dynamic balance, in older women.

Methods

This was a cluster randomized controlled trial. Physically independent older women (60–80 years) from day centers were randomly allocated to Pilates, Muscular and Control Groups (PG, MG and CG) using a block randomization method. Only the research staff performing the assessment and statistical analysis were blinded. Exercise groups trained twice a week (1 h per session) for 18 weeks in a moderate-to-vigorous intensity. Core strength (primary outcome): trunk and hip isometric and hip isokinetic muscular strength (Biodex System III Pro Isokinetic Dynamometer), alongside one leg static balance (portable force platform Kistler 9286AA) and dynamic balance (timed up and go (TUG)) were assessed.

Results

A total of 60 participants were randomized (PG, n = 20; MG, n = 20; CG, n = 20) and 49 completed the trial (PG, n = 16; MG, n = 19; CG, n = 14). Regarding hip isometric extension strength, PG was statistically better than CG (P = 0.004). There were no differences between groups regarding isokinetic strength or balance. Intra-group comparisons showed significant improvements (P < 0.05) in the dynamic balance and trunk and hip isometric extension strength for PG and MG, whereas every hip isokinetic measurement was improved in MG. Exercise programs did not produce any adverse event.

Conclusions

The Pilates training program was more effective for improving isometric hip and trunk extension strength, while the Muscular training program generated greater benefits on trunk and hip isokinetic strength. Moreover, both training programs showed moderate effects for the TUG.

Clinical Trial Registration

The trial was registered at ClinicalTrials.gov (identifier: NCT02506491).

Quantification of weakness caused by distal median nerve lesion by dynamometry

INTRODUCTION

In the assessment of hand and upper limb function, grip strength is of major importance. Use of the JAMAR dynamometer has been an accepted test of grip strength and routinely part of the physical examination.

PURPOSE OF THE STUDY

The aim of this study was to determine by means of a median nerve block simulating a patient group if the measurement of different types of grip force can improve the quantification of impairment of the hand beyond the sole power grip measurements.

METHODS

In 29 healthy volunteers, grip force measurement was done by the JAMAR dynamometer for power grip and by a pinch grip dynamometer for pincer grip, precision grip, pinch grip, and palmar abduction. At the power grip, the force of digit 2-5 was measured separately by a sensor glove. For each measurement, 3 trials were recorded subsequently.

STUDY DESIGN

A within-subject research design was used in this prospective study. Each subject served as the control by preinjection measurements of grip and pinch strength. Subsequent measurements after median nerve block were used to examine within-subject change.

RESULTS

In power grip, there was no significant reduction of maximum grip force with median nerve block compared with grip force without block. By measuring the finger forces by a sensor glove, a reduction of force at the individual fingers was found compared with the setting with no block, although significant only at the middle finger (P < .017). With median nerve block, average grip force decreased significantly 20% in pincer grip (P < .021), 29.5% in pinch grip (P < .002), 39.5% in precision grip (P < .001), and 70.7% in palmar abduction (P < .013).

CONCLUSIONS

These experiments suggest a minor role of the measurement of the power grip force in the diagnostics of distal median nerve block with the dynamometer, which could not be substantially improved by the digit forces and the force distribution of the individual fingers. The assessment of other grip forms, such as pincer grasp, precision grip, pinch grip, and especially palmar abduction, leads to a relevant improvement in the diagnostics of distal median nerve lesion.

LEVEL OF EVIDENCE

II.

Measurement of Active Motor Threshold Using a Dynamometer During Navigated Transcranial Magnetic Stimulation in a Patient with Postoperative Brain Tumor: Technical Note

BACKGROUND

Navigated transcranial magnetic stimulation (nTMS) is being used for different purposes in patients with brain tumors. However, the procedure requires a positive electrophysiological response. For patients with negative response in rest conditions, active motor threshold (AMT) may be used. However, sometimes it is difficult to obtain AMT measures owing to inability of the patient to sustain steady muscle contraction. Herein, we describe a simple method by using a hand dynamometer to obtain AMT measures during nTMS session.

CASE DESCRIPTION

A woman aged 68 years underwent total removal of a right frontal lobe oligodendroglioma World Health Organization grade II 15 years ago. Cranial magnetic resonance imaging during follow-up revealed local recurrence. In the postoperative period, she developed left upper limb paresis. A postoperative nTMS session was performed for motor electrophysiological evaluation. However, using the standard technique for AMT measurement, the patient was unable to perform sustained muscle contraction as required. A hand dynamometer was used. It allowed sustained muscle contraction for AMT measurement. A counter force for the index finger flexion, the hand support to stabilize hand joints, and a numerical screen serving for both the examiner and the patient as a feedback parameter may explain the success obtained with this simple device.

CONCLUSIONS

Although more studies are necessary to validate the method, the hand dynamometer should be considered for patients unable to sustain muscle contraction during AMT measurement.

Comparison of psychometric properties between the Labin, a new electronic dynamometer, and the Jamar: Preliminary results in healthy subjects

Many instruments exist for measuring grip strength. The Jamar hydraulic hand dynamometer is currently the gold standard. The Labin is a prototype electronic dynamometer that can also measure maximum grip strength. The main objective was to compare the Labin dynamometer with the gold standard instrument, the Jamar, in a healthy population, and secondarily to compare discomfort during use. A single-center exploratory study was conducted. The subjects enrolled had to be aged between 20 and 60, be volunteers and give consent. The required number of subjects was 30. The subjects were positioned according to American Society of Hand Therapists recommendations. Maximum grip force was measured in kilograms using the mean of three successive trials. The first dynamometer used was chosen randomly. The handle's discomfort during use was rated on a simple verbal scale from 0 to 10. Thirty-four subjects were included. The concordance coefficient for peak torque between the Labin and Jamar dynamometers was 0.90 for the dominant hand and 0.83 for the non-dominant hand. The intraclass correlation coefficient for peak torque with the Labin was 0.81 [0.69; 0.89] for the dominant hand and 0.86 [0.76; 0.92] for the non-dominant hand. In our study, we have shown that the Labin prototype has acceptable validity and reproducibility. The Labin will need to be tested in pathological conditions next.

The Measurement Methods of Movement and Grip Strength in Children with a Previous Upper Extremity Fracture: A Comparative, Prospective Research

BACKGROUND AND AIMS

Decreased range of motion of the elbow and forearm and decreased grip strength are potential findings following a childhood upper extremity fracture. Clinical follow-up is essential because spontaneous improvement is seen several months after the injury. Freehand measuring with a goniometer and hydraulic dynamometer is used to evaluate clinical result. The new methods are justified in avoiding human typewriting errors, thus improving patient safety. Nevertheless, their feasibility in child patients is unknown. This study aimed to evaluate congruence between the computer-assisted and the free-hand measuring methods.

MATERIALS AND METHODS

A total of 59 children with a previous supracondylar humerus fracture were clinically examined by means of free-hand (transparent goniometer and hydraulic dynamometer; Jamar, Lafayette Ltd.) and computer-assisted (E-Link System Packages, Biometrics Ltd.) methods. The range of motion and grip strength were measured separately using both methods. Agreement between the measurements was evaluated using the Bland-Altman method.

RESULTS

The results between the two methods were incongruent and the differences between measurements increased along with the mean of measurements in all categories except elbow extension. Rotational range of motions were smaller and grip strength was weaker while measuring with the computer-assisted method. The mean discrepancy was 0.97° (95% confidence interval = -2.46 to 0.53) for elbow extension and 7.97° (95% confidence interval = 6.60-9.33) for elbow flexion.

CONCLUSIONS

Grip strength is used to evaluate impairment of hand function. The study method showed slightly lower results in grip strength. Range of motion is essential when evaluating the outcome of supracondylar humerus fracture, while >10° of change in elbow range of motion associate with impaired function. As compared with the gold-standard goniometer, the methods were not congruent. However, all differences were under 10° and probably beyond clinical importance. Because of its advantages in recording the outcomes to electronical charts, the computer-assisted method is recommended option in performing the follow-up of complicated pediatric supracondylar humerus fractures.

Potentials of Smart dynamometer use for clinical and self-management of rehabilitation in breast cancer survivors: a feasibility study

The aim of this study was to examine the feasibility of the Smart dynamometer as a rehabilitation exercise device in a daily care by comparing with the existing medical devices. We used and analyzed clinical and measurement data of breast cancer survivors who have used Smart dynamometer during their rehabilitation after breast cancer surgery. The Smart dynamometer was compared with the two existing devices of Takei dynamometer and surface electromyography (sEMG) that were used in routine care, respectively. Three key components of the rehabilitation exercise devices were analyzed to validate the feasibility of the Smart dynamometer: grip strength, reaction time, and grip endurance time. Pearson's correlation analysis was performed to compare the statistical significance between the devices. The data of 12 and 15 female breast cancer patients were analyzed for comparing the Smart dynamometer with Takei dynamometer and sEMG, respectively. There was a very weak correlation between the maximum values from the Takei and the Smart dynamometers in the affected and non-affected arms of breast cancer patients (r = 0.5321, 0.4733). Comparisons of 3 features between the Smart dynamometer and sEMG showed that there were strong positive correlations for both reaction time and endurance time in the affected and non-affected arms (r > 0.9). The feasibility of the Smart dynamometer for the possible use in a daily rehabilitation exercise was partially verified. Moreover, since the Smart dynamometer was highly correlated with time-related variables, it was important and significant to measure both grip strength and time-related information.

Comparison of shoulder strength assessment in scaption with an isometric dynamometer and a weighing machine: a pilot study

Background

Strength testing is an important aspect of shoulder examination. To date, strength assessment has many limitations. There is no single standard instrument for measuring, and various current devices have problems in reliability, accuracy, and cost. This study compared the results of an innovative and simple method of strength testing (weighing machine) with an existing method (isometric dynamometer).

Methods

Shoulder strength was tested in 80 individuals, 60 with normal shoulders (group 1) and 20 with shoulder pathology (group 2). Strength was tested in the standard position of 90° of elevation in the scapular plane (scaption) with the elbow extended and forearm pronated while resistance was applied just proximal to the wrist. A weighing machine and an isometric dynamometer were used for strength testing.

Results

There was a mean difference of 0.26 kg in group 1 (95% confidence interval [CI], 0.16-0.36; P < .0001) and 0.30 kg in group 2 (95% CI, 0,04-0,72; P = .0291) between the weighing machine and the isometric dynamometer. Although statistically significant, these differences were not clinically significant.

Conclusions

This pilot study shows that strength assessment by an innovative and simpler technique with a weighing machine gives similar results as an isometric dynamometer.

Easy method for measuring stretching intensities in real clinical settings and effects of different stretching intensities on flexibility

BACKGROUND

Flexibility changes according to stretching intensity have been rarely investigated. I aimed to assess the effect of different stretching intensities on hamstring flexibility by measuring them in a setting similar to real clinical settings.

METHODS

Stretching intensities were quantified using an easy method, and participants were grouped according to intensity: 100% (P100), 70% (P70), 40% (P40), and 10% (P10) of maximum voluntary isometric contraction. Proprioceptive neuromuscular facilitation stretching intensities were measured using a sling system and tension dynamometer. Hamstring flexibility was measured (before; immediately after; and 3, 6, 9, 12, and 15 min after stretching) using the active knee extension test. Flexibility was compared between subgroups, and longitudinal changes in flexibility were additionally observed in each group.

RESULTS

At identical time points, no significant difference in hamstring flexibility was found between the high-intensity (P100) and moderate-intensity (P70, P40) groups. A significant difference was found between P100 and P10 immediately after and 12 and 15 min after stretching. Increased flexibility was maintained until the end in P100 and P70 but not P40 and P10.

CONCLUSIONS

High-intensity and moderate-intensity stretching increases flexibility compared with low-intensity stretching. Furthermore, high-intensity stretching was superior to moderate-intensity stretching in terms of maintaining flexibility over time.

The late effect of Kinesio Taping® on handgrip strength

Kinesio Taping^® elastic tape is increasingly used in physiotherapy treatment. However, there is a lack of scientific research regarding the late effects of its use. This study quantified the late effects of applying the Kinesio Taping^® elastic tape by measuring changes in handgrip muscle strength after 24, 48 and 72 h of application. The Kinesio Taping^® elastic tape was applied on the dominant and non-dominant limbs of 36 volunteers randomly assigned to three groups: muscle facilitation, muscle inhibition and control group. The statistical test showed there was a statistically significant difference among all groups of dominant limb and non-dominant limb. However, the analysis on intragroup relationship to periods of application (Initial, 24, 48 and 72 h) and the interaction among repeated measures showed there was no statistically significant difference. This result may contribute to the investigation of the late effects of the Kinesio Taping^® elastic tape on the physical rehabilitation.

Bone mineral density, hand grip strength, smoking status and physical activity in Polish young men

The human skeleton undergoes constant changes encompassing the phases of growth, consolidation and involution of the bone tissue. The aim of the research was to assess the relationship between bone mineral density (BMD) and such factors as hand grip strength, somatic structure or attitudes to tobacco smoking in men with different levels of physical activity. The study included 172 males aged 20-30 years. Mineral density and forearm bone mass were measured using the dual-energy X-ray absorptiometry method. Physical activity levels were assessed with the use of the International Physical Activity Questionnaire. Hand grip strength was measured with Jamar hand dynamometer. Attitudes towards smoking were assessed using the Global Adult Tobacco Survey. The correlation between a high level of physical activity among men and higher BMD and bone mass both in the distal and proximal parts of the forearm was statistically significantly greater compared to individuals with an insufficient level of physical activity. A better state of BMD and higher bone mass in both forearm bones was noted among non-smoking men. A high level of physical activity was the most significant predictor of BMD in the distal part of the forearm. The regression analysis in the proximal part revealed that body mass and a high level of physical activity were the most important predictors of BMD. The lack of physical activity was associated with more frequent occurrence of low bone mass in men. Tobacco smoking may be one of the most important risk factors of poor bone mineralization in young men.

Association of hand grip strength with disease activity, disability and quality of life in children and adolescents with Juvenile Idiopathic Arthritis

BACKGROUND

Juvenile idiopathic arthritis (JIA) affects wrist and hand joints leading to decrease hand function and patients' daily living activities. The assessment of hand grip strength (HGS) in children and adolescents with JIA is of major importance, and the association of HGS with JIA disease activity, disability and quality of life has not been explored. The primary objective of this study was to evaluate hand grip strength (HGS) in children and adolescents with Juvenile Idiopathic Arthritis (JIA) compared to matched healthy peers. The secondary objective was to explore the relationship between HGS and JIA disease activity, disability, and quality of life.

METHODS

This study involved 23 patients with JIA and 46 age and sex matched healthy controls. Hand held dynamometer was used to evaluate HGS for all study participants. Anthropometric parameters for all study participants were measured. Disease activity, physical function, and quality of life were assessed for the JIA group using juvenile arthritis disease activity score (JADAS-27), juvenile arthritis functionality scale (JAFS), and pediatric quality of life inventory (PedsQL) respectively. Laboratory marker of inflammation, erythrocyte sedimentation rate (ESR), and plain radiography of hands were performed for all patients.

RESULTS

Hand grip strength of children and adolescents with JIA was significantly weaker compared to matched controls (p < 0.001). Hand grip strength had a significant inverse correlation with JADAS-27 (r = - 0.467, p = 0.025), JAFS (r = - 0.650, p = 0.001) and a significant direct correlation with PedsQL (r = 0.438, p = 0.036). In addition, HGS was negatively correlated with ESR and duration of morning stiffness (r = - 0.489, p = 0.018 and r = - 0.201, p = 0.359, respectively). HGS was detected as an independent predictor of disease activity, disability, and quality of life in JIA patients in multivariate linear regression.

CONCLUSIONS

Assessment of HGS could be a simple non-invasive tool for assessing disease activity, disability and quality of life in JIA patients in clinical practice.

Assessment of lower extremity muscle mass, muscle strength, and exercise therapy in elderly patients with diabetes mellitus

The increase in the proportion of elderly people in the population is one of the most remarkable sociodemographic phenomena of the twenty-first century. The number of patients with diabetes is also increasing worldwide with this demographic change. Given these facts, consideration of the problems the general elderly population is facing in the management of diabetes is essential. In this review article, we focus on sarcopenia, which is the decrease in lower extremity muscle mass and muscle strength accompanying aging, describe the relationship between sarcopenia and diabetes, and highlight the specific factors through which diabetes contributes to loss of muscle strength. The quantitative methods for evaluating lower extremity muscle strength will also be described. These methods hold the key to assessing the effectiveness of exercise therapy and optimizing the assessment of the degree of autonomy in the activities of daily living. Exercise is one of the basic treatments for type 2 diabetes and may also prevent and improve sarcopenia. This review discusses the aspects common to the two health conditions and elucidates the effectiveness and necessity of exercise as a preventive measure against diabetes among the elderly.

Trunk musculoskeletal response in maximum voluntary exertions: A combined measurement-modeling investigation

Maximum voluntary exertion (MVE) tasks quantify trunk strength and maximal muscle electromyography (EMG) activities with both clinical and biomechanical implications. The aims here are to evaluate the performance of an existing trunk musculoskeletal model, estimate maximum muscle stresses and spinal forces, and explore likely differences between males and females in maximum voluntary exertions. We, therefore, measured trunk strength and EMG activities of 19 healthy right-handed subjects (9 females and 10 males) in flexion, extension, lateral and axial directions. MVEs for all subjects were then simulated in a subject-specific trunk musculoskeletal model, and estimated muscle activities were compared with EMGs. Analysis of variance was used to compare measured moments and estimated spinal loads at the L5-S1 level between females and males. MVE moments in both sexes were greatest in extension (means of 236 Nm in males and 190 Nm in females) and least in left axial torque (97 Nm in males and 64 Nm in females). Being much greater in lateral and axial MVEs, coupled moments reached ∼50% of primary moments in average. Females exerted less moments in all directions reaching significance except in flexion. Muscle activity estimations were strongly correlated with measurements in flexion and extension (Pearson's r = 0.69 and 0.76), but the correlations were very weak in lateral and axial MVEs (Pearson's r = 0.27 and 0.13). Maximum muscle stress was in average 0.80 ± 0.42 MPa but varied among muscles from 0.40 ± 0.22  MPa in rectus abdominis to 0.99 ± 0.29 MPa in external oblique. To estimate maximum muscle stresses and evaluate validity of a musculoskeletal model, MVEs in all directions with all coupled moments should be considered.

The Scientific Illusion of Victor Burq (1822-1884)

Victor Burq (1822-1884) is closely associated with a therapy named "burquism" by Jean-Martin Charcot, which was used in treating hysteria, especially hysteric anesthesia and paralysis, by applying metals, mainly copper, to affected zones. In 1876, Charcot, Luys, and Dumontpallier, commissioned by the Société de Biologie, issued 2 opinions validating the results obtained by Burq during the 25 years he dedicated to his research. From that point forward, the careers of these 3 famous physicians were lastingly reoriented toward the practice of hypnosis. This neo-mesmeric resurgence at the end of the nineteenth century can be considered the cause of an epistemological change that gave rise to "psychological medicine." During the repeated cholera epidemics in the mid-nineteenth century, Burq recommended preventive and corrective ingestion of copper, after observing that smelter workers were unaffected by the disease. The mechanisms of copper's anti-bacterial action have since been elucidated and legitimize Burq's anti-cholera campaign. Burq also advocated the ingestion of copper sulphate to treat diabetes. Current-day findings on intestinal microbiota and how these organisms influence blood sugar regulation support Burq's claims, considered far-fetched for many years.

High-intensity stretch-shortening contraction training modifies responsivity of skeletal muscle in old male rats

Utilization of high-intensity resistance training to counter age-related sarcopenia is currently debated because of the potential for maladaptation when training design is inappropriate. Training design is problematic because the influence of various loading variables (e.g. contraction mode, repetition number, and training frequency) is still not well characterized at old age. To address this in a precisely controlled manner, we developed a rodent model of high-intensity training consisting of maximally-activated stretch-shortening contractions (SSCs), contractions typical during resistance training. With this model, we determined that at old age, high-repetition SSC training (80 SSCs: 8 sets of 10 repetitions) performed frequently (i.e. 3 days per week) for 4.5 weeks induced strength deficits with no muscle mass gain while decreasing frequency to 2 days per week promoted increases in muscle mass and muscle quality (i.e. performance normalized to muscle mass). This finding confirmed the popular notion that decreasing training frequency has a robust effect with age. Meanwhile, the influence of other loading variables remains contentious. The aim of the present study was to assess muscle adaptation following modulation of contraction mode and repetition number during high-intensity SSC training. Muscles of young (3 month old) and old (30 month old) male rats were exposed to 4.5 weeks of low-repetition static training of 4 (i.e. 4 sets of one repetition) isometric (ISO) contractions 3 days per week or a more moderate-repetition dynamic training of 40 SSCs (i.e. 4 sets of 10 repetitions) 3 days per week. For young rats, performance and muscle mass increased regardless of training protocol. For old rats, no muscle mass adaptation was observed for 4 ISO training while 40 SSC training induced muscle mass gain without improvement in muscle quality, an outcome distinct from modulating training frequency. Muscle mass gain for old rats was accompanied by decreased protein levels of tumor necrosis factor alpha, a mediator of age-related chronic inflammatory signaling, to young levels. These findings suggest that while dynamic high-intensity training with a moderate number of repetitions has a limited capacity for altering muscle quality, such training is a viable strategy for countering age-related inflammatory signaling and modifying muscle mass.

No significant correlation between the intensity of static stretching and subject's perception of pain

[Purpose] The purpose of this study was to determine whether the intensity of static stretching measured quantitatively is related to subjects’ perception of pain. [Subjects and Methods] Sixty-eight participants were recruited. Static stretching was performed once for 30 seconds while maintaining the knee at 0° flexion and was continued to the point where pain was recognized. The intensity of stretching exerted by the practitioner was quantitatively measured by using a handheld dynamometer (HHD). A subject’s pain scaled on one’s perception was measured by using the visual analog scale (VAS). [Results] No significant correlation was found between the intensity of stretching and the VAS score representing the subject’s pain scaled on one’s perception. In this study, the most frequent VAS score was 7, and the mean VAS score was 5.57 ± 1.77. The stretching intensity measured by using a HHD ranged from 28.4 to 133.0 N (mean, 72.04 ± 22.37 N). [Conclusion] This study showed that the intensity of stretching quantitatively measured by using HHD did not correlate with the degree of pain reported by the subjects. Therefore, subjective responses cannot guarantee a consistent application of intensity.

Forces generated in stabbing attacks: an evaluation of the utility of the mild, moderate and severe scale

The commonest way of killing in the UK is by a sharp instrument. Knight reported in 1975 that it is impossible to discern with any degree of certainty the degree of force used to create a stab wound. Despite this, expert witnesses continue to approximate the degree of force used for their reports and evidence in court. It is usually subjectively categorized as mild, moderate or severe, based solely on the examination of the wound. We undertook a study considering forces generated in a range of blunt trauma actions, using a novel force plate dynamometer to measure the peak forces obtained by adult male and female volunteers. We then studied forces generated by stabbing skin simulants and porcine samples with knives and screwdrivers. Men generated more force than women during stabbings which was found to be equivalent to somewhere between the blunt trauma actions of pushing a button to a single-handed push. When asked to stab using what they thought was mild, moderate and severe force, although volunteers were able to actively decide the force used, the actual force was found to be influenced by the weapon, sex of the individual, hand used and biological/anatomical site penetrated. This study shows that the forces generated by volunteers in mild, moderate and severe stabbing tests in almost all cases were significantly greater than the forces required for skin penetration. We suggest that the use of subjective force scales is inappropriate. Rather than use of a subjective scale, we suggest that the force required in any stabbing requires investigation in four areas: the tip radius of the weapon, minimal force required for penetration, the sex of the assailant and whether the force required for penetration is greater than that that can be generated by a person stabbing. This allows for the use of an evidence-based two-tier scale to suggest the force required.

Do isometric, isotonic and/or isokinetic strength trainings produce different strength outcomes?

INTRODUCTION

Several studies have been developed to determine which type of muscular action (isometric, isotonic and isokinetic) elicits more gains in functional strength and muscle mass. The comparisons between training outcomes are inconclusive due to lack of exercise standardization.

OBJECTIVE

To compare muscle strength, mass, and functional performance in response to isometric, isotonic, and isokinetic contractions, when training loads (volume and intensity) are equated.

METHOD

Data were derived from a university community-recruited sample (n = 31 men).

INTERVENTIONS

Untrained men were assigned to isotonic (IT), isometric (IM), or isokinetic (IK) group, and trained their dominant quadriceps muscle 3 sessions/week for 8 weeks with a dynamometer. Muscle strength was assessed using Cybex 6000 dynamometer; the triple-hop-distance test was used to assess functional performance, and dual energy x-ray absorptiometry to assess lean muscle mass.

RESULTS

After training, muscle lean muscle mass increased in isometric (+3.1%, p < 0.01) and isotonic groups (+3.9%, p < 0.01); only the isokinetic group showed a significant improvement in the triple-hop-distance test (4.84%, p < 0.01).

CONCLUSION

Clinicians should consider isometric training as an alternative for isotonic training to gain muscle mass, and isokinetic training to improve functional performance of daily activities and/or sports.

PEAK HIP MUSCLE TORQUE MEASUREMENTS ARE INFLUENCED BY SAGITTAL PLANE HIP POSITION

BACKGROUND

An optimal position for strength testing of the hip musculature has not been identified. However, sagittal plane hip position during testing has been shown to influence hip external rotation strength.

HYPOTHESIS/PURPOSE

The purpose of this study was to compare hip extension, external rotation, and abduction isometric torque at positions with differing degrees of hip flexion using a handheld dynamometer.

STUDY DESIGN

A cross-sectional laboratory study.

METHODS

Twenty-nine healthy and physically active females participated in this study. Peak isometric contractions were measured with a handheld dynamometer secured with a non-elastic strap and then converted to torque using segment lengths. Hip external rotation and extension were tested at 0°, 30°, and 90° of hip flexion. Hip abduction was tested at 0° and 30° of hip flexion and 5° of extension. Testing was randomized and counterbalanced. Repeated measures ANOVAs with Sidak's test for multiple comparisons were used for statistical analysis. Significance was set at p<0.05.

RESULTS

Significant main effects were found for hip extension (p<0.001) and external rotation (p<0.027), but not for abduction (p=0.085). Pairwise comparisons showed significant differences between all three testing positions for hip extension torque (0°v30° : p<0.001, 0°v90° : p<0.001, 30°v90°: p=0.002). Extension torque was highest in 90° of flexion (1.43 ± 0.50 Nm/kg*m) and lowest in 0° of flexion (0.83 ± 0.30 Nm/kg*m). Comparisons of hip external rotation torque tested at 0°v90° (p=0.096) and 30°v90° (p=0.080) were not significantly different but did have medium effect sizes. External rotation torque was highest in 90° of flexion (0.29 ± 0.13 Nm/kg*m).

CONCLUSIONS

Direct comparisons of torque values of hip extension and external rotation tested at different sagittal plane positions should be cautioned due to differences. Hip extension and external rotation should be measured in consistent sagittal plane positions across examiners and testing sessions. Test position will be dependent upon the goals of strength testing.

LEVEL OF EVIDENCE

2b.

Mean Hand Grip Strength and Cut-off Value for Sarcopenia in Korean Adults Using KNHANES VI

The purpose of this study was to report age- and gender-specific distribution of the hand grip strength (HGS) using data from the Korea National Health and Nutrition Examination Survey (KNHANES) VI-3 (2015) survey and determine cut-off values for low muscle strength of HGS of Koreans. Of a total of 7,380 participants, 4,553 were subjected to measurements of HGS, including 1,997 men and 2,556 women with a mean age of 49.3 years (range, 19-80 years). The mean ages of men and women were 49.0 and 49.5 years, respectively. HGS was measured using a digital hand dynamometer. It was defined as maximal measured grip strength of the dominant hand. The cut-off value for low muscle strength was defined as the lower 20th percentile of HGS of the study population. Maximum grip strength of men was significantly higher than that of women (40.2 kg in men vs. 24.2 kg in women, P < 0.001). The mean HGS was increased from the age of 19 to 39 years. It was peaked in the age of 35 to 39 years range for both men and women. It was then decreased after 39 years. The cut-off values of HGS in male and female elderly healthy populations were 28.6 and 16.4 kg, respectively. These data might be used as reference values when evaluating sarcopenia and assessing hand injuries.

Handgrip strength as a means of monitoring progression of cognitive decline - A scoping review

Cognitive decline in older adults contributes to reduced ability to perform daily tasks and continued disuse leads to muscle weakness and potentiates functional loss. Despite explicit links between the motor and cognitive systems, few health care providers assess motor function when addressing the needs of individuals with cognitive loss. Early and easy measurable biomarkers of cognitive decline have the potential to improve care for individuals with dementia and mild cognitive impairment. The aim of this study was to conduct a systematic search to determine the relationship among handgrip strength, as a measure of global muscle strength, and cognitive decline over time. Fifteen prospective, cohort, longitudinal studies of adults >60years old who were healthy or at risk of cognitive decline at study onset were included in the review. Studies that investigated changes in cognition relative to baseline grip strength and, those that investigated changes in grip strength relative to cognitive function were revealed. Findings here support the use of handgrip strength as a way to monitor cognitive changes and show that reduced handgrip strength over time may serve as a predictor of cognitive loss with advancing age.

[Diagnostic ability of power measurement of different grip forms for distal median nerve lesion]

BACKGROUND

Peripheral lesions of the median nerve cause characteristic changes of the grip function of the hand. For evaluating grip force changes, measurement by dynamometers (JAMAR dynamometer and pinch dynamometer) is of high relevance. In this study the ability of grip force measurements of different grip forms was evaluated to discriminate between a simulated median nerve lesion and healthy subjects.

MATERIAL AND METHODS

In 21 healthy subjects, the grip force of power grip was measured by the JAMAR dynamometer at the second stage including measurement of force at the fingertips and the thenar by a sensor glove. With a pinch dynamometer the power of palmar abduction, precision grip, pincer grip and pinch grip was determined. Measurements were performed with and without median nerve block at the wrist.

RESULTS

In power grip of the JAMAR dynamometer at the second stage a significant reduction of the grip force of 13.4% was found (p < 0.03). The power distribution between the fingers D2-D5 did not change with median nerve block. The most relevant reduction of grip force in median nerve block compared with the healthy control was measured in palmar abduction (72.1%, p < 0.0002), followed by precision grip 31.0% (p < 0.0001), pincer grip 23.6% (p < 0.0004) and pinch grip 18.8% (p < 0.0002).

CONCLUSIONS

For the discrimination between healthy subjects and subjects with a median nerve block there was a limited relevance of the measurement of the power grip and force distribution at the fingers by the JAMAR dynamometer. However, the best distinction was observed by dynamometric measurement of other grips than power grip, such as palmar abduction, precision grip, pincer grip and pinch grip. The results could be relevant for the clinical diagnostics and rehabilitation of median nerve lesion, complementing the widespread measurement of the power grip by other grip forms.