Comparative assessment of knee extensor and flexor muscle strength measured using a hand-held vs. isokinetic dynamometer

Association of endothelial dysfunction and peripheral arterial disease with sarcopenia in chronic kidney disease

BACKGROUND

Endothelial dysfunction and peripheral arterial disease (PAD), which disturb skeletal muscle microperfusion, are highly prevalent in patients with chronic kidney disease (CKD). We evaluated the association of endothelial dysfunction and PAD with sarcopenia in patients with non-dialysis CKD.

METHODS

This cross-sectional study included 420 patients with stages 3-5 non-dialysis CKD aged 69.0 ± 11.8 years. Skeletal muscle index (skeletal muscle mass/height2), handgrip strength, 6-m gait speed and strength of hip flexion and knee extension were measured. Sarcopenia was defined according to the Asian Working Group for Sarcopenia 2019. Endothelial dysfunction and PAD were assessed using the vascular reactivity index (VRI) and ankle-brachial index (ABI), respectively. A VRI < 1.0 was classified as poor endothelial function, and an ABI < 0.9 was defined as PAD. Additionally, endothelial and inflammatory biomarkers, including intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), asymmetric dimethylarginine, endothelin-1 (ET-1) and interleukin-6, were measured in a subgroup of 262 patients.

RESULTS

Among the participants, 103 (24.5%) were classified as having sarcopenia. Compared with patients without sarcopenia, those with sarcopenia had significantly lower ABI (1.04 ± 0.16 vs. 1.08 ± 0.15, P = 0.028 for the right ABI; 1.01 ± 0.16 vs. 1.06 ± 0.16, P = 0.002 for the left ABI) and VRI (0.83 ± 0.57 vs. 1.08 ± 0.56, P < 0.001) and had higher serum levels of ICAM-1 (P < 0.001), VCAM-1 (P = 0.003) and ET-1 (P = 0.037). Multivariate logistic regression revealed that, beyond age and body mass index, the average ABI (odds ratio [OR]: 0.81/0.1 increase; 95% confidence interval [CI]: 0.67-0.98; P = 0.032) and VRI (OR: 0.93/0.1 increase; 95% CI: 0.88-0.98; P = 0.010) were independently associated with sarcopenia. Among the endothelial biomarkers measured, ICAM-1 (OR: 2.47/1-SD increase; 95% CI: 1.62-3.75) and VCAM-1 (OR: 1.91/1-SD increase; 95% CI: 1.27-2.87) were independent predictors of sarcopenia. Group stratification based on the cut-offs of VRI and ABI showed that those with both poor VRI and ABI had the greatest risk for sarcopenia (OR: 4.22; 95% CI: 1.69-10.49), compared with those with normal VRI and ABI.

CONCLUSIONS

Endothelial dysfunction and PAD are independently associated with sarcopenia in patients with stages 3-5 CKD, suggesting the dominant role of vascular dysfunction in sarcopenia.

Investigation of factors associated with static and dynamic balance in early-stage lung cancer survivors

PURPOSE

Balance impairment and falls are common among patients after cancer treatment. This study aimed to compare static and dynamic balance functions in lung cancer survivors (LCS) and healthy controls and to investigate the factors related to balance in LCS.

METHODS

Cross-sectional data were collected from lung cancer patients whose treatment had been completed within the previous 3 months (n = 60) and age and gender-matched healthy controls (n = 60). Clinical characteristics and history of falls were recorded. Pulmonary function tests and measurements of respiratory muscle strength were performed. Dynamic and static balance, fear of falling, knee-extension strength, physical activity level, dyspnea, comorbidity, and quality of life (QoL) were assessed using the Time Up and Go Test, Single Leg Standing Test, the Fall Efficacy Scale-International, hand-held dynamometer, the International Physical Activity Questionnaire, the Modified Medical Research Dyspnea Scale, the Charlson Comorbidity Index, and the European Organization for Research and Treatment of Cancer QoL Scale.

RESULTS

LCS reported a higher fall rate and exhibited lower dynamic balance compared to controls (p < 0.05). The number of chemotherapy cycles, number of falls in the past year, fear of falling, perceived dyspnea, forced expiratory volume in 1 s (%), maximal inspiratory pressure (%), knee-extension strength, physical activity score, and QoL score related to physical function were correlated with balance function in LCS (p < 0.05).

CONCLUSION

LCS had a higher risk of falls and lower dynamic balance function which might be related to various clinical and physical parameters.

IMPLICATIONS FOR CANCER SURVIVORS

Identifying factors related to balance should be considered within the scope of fall prevention approaches for these patients.

Changes in Functional Outcomes After an Inpatient Rehabilitation Program for Solid-Organ Transplant Recipients

Introduction: Outpatient exercise training has been shown to be beneficial for solid organ transplant recipients. Little is known about the effects of inpatient rehabilitation programs for recipients with a more complicated postoperative course. Research Question: This study was designed to (1) describe the changes in functional outcomes after an inpatient rehabilitation program, and (2) determine whether the changes in lower body strength and quadriceps strength are associated with changes in functional exercise capacity. Design: This was a single-arm prospective longitudinal study. The recipients participated in an inpatient rehabilitation program twice a day, 7 days a week for 3 to 4 weeks. Outcome Measures Included: 2-Minute Walking Test, Timed Up and Go, Berg Balance Scale, 30-Second Sit to Stand, biceps and quadriceps strength, Functional Independence Measure, SF-36, and Canadian Occupational Performance Measure. Results: Twenty-eight patients (54% female, mean age = 55 [11]) completed the study. Participants were mostly liver (42%) and lung recipients (35%). There were statistically significant improvements in all outcomes after the intervention. There was no relationship between changes in functional exercise capacity and quadriceps strength or lower body strength. Conclusion: An inpatient rehabilitation program may improve several functional outcomes and health-related quality of life in transplant recipients with a complicated postoperative course.

The Effect of High-Speed Power Training on Physical Frailty in Older Adults: Effect of a Visual-Guided Exercise Program in South Korean Rural Areas

Objective

Exercise has been shown to be an effective intervention; the difficulty still lies in providing exercise programs to the older adults in rural areas. Therefore, this study aimed to examine the effects of a 12-week exercise program provided with visual guidelines (prerecorded video) on frailty among older adults in rural areas.

Methods

Fifty participants (71.7 ± 4.9 years) from 5 different rural areas were recruited and divided into two groups: the exercise group (EX, n = 24 (male: 8, female: 18)) and the control group (CON, n = 26 (male: 7, female: 17)). With the commencement of the exercise intervention, a prerecorded high-speed power training program for frail older adults was distributed to the EX group. A new prerecorded exercise program was delivered to the EX group every 4 weeks. Frailty status was diagnosed with Fried's criteria before and after the intervention. Muscle strength was measured in the upper and lower limb strength (hand-grip strength and leg extension and flexion), and physical function was measured using a short physical performance battery and gait speed. Fasting blood was collected before and after the intervention and analyzed for blood lipid profile.

Results

After 12 weeks of the intervention period, a significant difference in frailty status (P < 0.01) and score (P < 0.01) favoring the EX group was observed. Physical functions (gait speed (P=0.01) and time for sit to stand (P < 0.01)) were significantly improved in the EX group with a significant increase in knee extensor strength (P < 0.01). A significant difference in serum high-density lipoprotein levels favoring the EX group (P=0.03) was also observed.

Conclusions

This study confirmed the positive effect of a visual-guided exercise program on older adults' residents in rural areas and provided alternative methods to effectively provide exercise program for the older adults with limited resources.

Investigating The Association Between Supraspinatus Tendon Abnormality, Shoulder Pain and Isokinetic Strength in Elite Swimmers: A Cross-Sectional Study

Shoulder pain is common among elite swimmers due to the tremendous stress over shoulders during swimming. Supraspinatus muscle is one of the major prime movers and stabilizers of shoulder and is highly susceptible to overloading and tendinopathy. An understanding of the relationship between supraspinatus tendon and pain; and between supraspinatus tendon and strength would assist health care practitioners for developing training regime. The objectives of this study are to evaluate 1) the association between structural abnormality of supraspinatus tendon and shoulder pain and 2) the association between structural abnormality of supraspinatus tendon and shoulder strength. We hypothesized that structural abnormality of supraspinatus tendons positively associated with shoulder pain and negatively associated with shoulder muscle strength among elite swimmers. 44 elite swimmers were recruited from the Hong Kong China Swimming Association. Supraspinatus tendon condition was evaluated using diagnostic ultrasound imaging and shoulder internal and external rotation strength was evaluated by the isokinetic dynamometer. Pearson's R was used to study the correlation between shoulder pain and supraspinatus tendon condition and to evaluate the association between isokinetic strength of shoulders and supraspinatus tendon condition. 82 shoulders had supraspinatus tendinopathy or tendon tear (93.18%). However, there was no statistically significant association between structural abnormality of supraspinatus tendon and shoulder pain. The results showed that there was no association between supraspinatus tendon abnormality and shoulder pain and there was a significant correlation between left maximal supraspinatus tendon thickness (LMSTT) and left external rotation/ concentric (LER/Con) and left external rotation/ eccentric (LER/Ecc) shoulder strength (p < 0.05) while internal rotation/ external rotation (IR/ER) ratio can also be a significant predicator on LMSTT >6mm (R² = 0.462, F = 7.016, df = 1, p = 0.038). Structural change of supraspinatus tendon was not associated with shoulder pain, but could be a predictor on MSTT >6mm in elite swimmers.

RELIABILITY OF THE ISOMETRIC DYNAMOMETER IN CONTROL, PARAPLEGIC, AND AMPUTEE INDIVIDUALS

Objective

To determine the Intraclass Correlation Coefficient (ICC), Standard Error of Measurement (SEM), Minimum Detectable Change (MDC), and the Minimum Clinically Important Difference (MCID) of the isometric measurements of muscle strength of trunk extension and of flexion and knee extension at maximum contraction in healthy, paraplegic, and amputee individuals, by using an isometric dynamometer with a belt for stabilization.

Methods

An observational cross-sectional study was carried out to assess the reliability of a portable isometric dynamometer in the trunk extension and flexion and knee extension movements of each group.

Results

In all measurements, ICC ranged from 0.66 to 0.99, SEM from 0.11 to 3.73 kgf, and MDC from 0.30 to 10.3 kgf. The MCID of the movements ranged from 3.1 to 4.9 kgf in the amputee group and from 2.2 to 3.66 kgf in the paraplegic group.

Conclusion

The manual dynamometer demonstrated good intra-examiner reliability, presenting moderate and excellent ICC results. Thus, this device is a reliable resource to measure muscle strength in amputees and paraplegics. Level of Evidence II, Cross-Sectional Study.

Can Clinician-Stabilization with Hand-Held Dynamometry Yield a Reliable Measure of Knee Flexion Torque?

Background

Assessment of knee flexion torque is a relevant clinical measure following various injuries and surgeries to determine progress in rehabilitation and inform decision making. A variety of methods using hand-held dynamometry have been shown to be reliable in obtaining this measure, and typically require a means of external fixation or stabilization. Clinically efficient methods of reliable clinician-stabilization are sparse in the literature.

Hypothesis/Purpose

Determine inter and intra-rater reliability of two clinically efficient methods of assessing isometric knee flexion torque using hand-held dynamometry with clinician-stabilization. The hypothesis was that each method would yield good to excellent reliability.

Study Design

Cross-Sectional Study.

Methods

Twenty healthy individuals were assessed by two clinicians on two separate days. During each session, knee flexion torque was assessed with hand-held dynamometry with two methods: 1) in the seated position with the hip and knee flexed to 90 degrees while the clinician stabilized the dynamometer between the participant's leg and table and 2) in prone with the hip at 0 degrees and knee at 90 degrees while the clinician assumed a stride stance with elbows locked in extension to stabilize the dynamometer on the participant's leg. Inter and intra-rater reliability were determined for each method.

Results

ICC values were 0.88-0.94 and 0.77-0.90 for inter and intra-rater reliability respectively with the seated method. The prone method yielded ICC values of 0.84-0.96 and 0.89-0.94 for inter and intra-rater reliability respectively. MDC values ranged from 30-62% with the seated method and 21-40% with the prone method.

Conclusion

Inter and intra-rater reliability were good to excellent for assessing knee flexion torque with hand-held dynamometry using both the seated and prone methods with clinically efficient clinician-stabilization approaches. The prone method may be more sensitive to detecting change over time due to lower MDC values.

Level of Evidence

2b.

The reliability of and agreement between devices used to measure eccentric hamstring strength: a systematic review protocol

BACKGROUND

Isokinetic dynamometry (IKD) is considered as the gold standard method of eccentric hamstring strength measurement, but other devices are more portable, cost-effective, provide real-time data and are thus better suited to the mass testing required in sport. This review aims to synthesise the evidence related to the reliability of and agreement between devices that measure eccentric hamstring strength and isokinetic dynamometers in adults.

METHODS

The MEDLINE, EMBASE, PubMed, CINAHL and Sport Discus databases, alongside a search of grey and pre-print literature (from inception to 2021), are used. Forward and backward snowballing will also be used. Studies will be included if the reliability and/or agreement between devices used to quantify eccentric hamstring strength in healthy, recreationally active or amateur/elite sportspeople has been investigated. Studies will be excluded if (1) participants were injured or unwell at the time of testing and (2) concentric strength measurements or if non-hamstring muscle groups were investigated. The COnsenus-based Standards for the selection of health Measurement INstruments (COSMIN) tool will be used to assess the quality of reporting of included studies. If possible, data will be pooled and a meta-analysis and/or meta-regression may be performed if appropriate. We will aim to conduct a narrative synthesis using an adapted Grading of Recommendation, Assessment, Development and Evaluation (GRADE).

DISCUSSION

This systematic review will aim to analyse the reliability of devices that measure eccentric hamstring strength, and the agreement of these devices with isokinetic dynamometers when used in an adult population. It is anticipated that the results of this review could be used to inform clinicians regarding suitable devices that can be employed to monitor eccentric hamstring strength in clinical practice. No ethics approval is required. It is anticipated that this review will be submitted to a leading peer-reviewed journal in this field for publication consideration.

SYSTEMATIC REVIEW REGISTRATION

www.researchregistry.com (reviewregistry1070).

Impaired Balance and Gait Characteristics in Patients With Chronic Heart Failure

BACKGROUND AND AIMS

Heart failure affects most systems of the body and causes various problems in patients. Balance deficits and gait deviations can be a result of these effects. There is little information in the literature about balance and gait parameters in chronic heart failure (CHF). This study aimed to investigate balance abnormalities together with gait deficits for possible associations in patients with CHF and compare them to healthy controls.

METHODS

Twenty-two (22) patients with CHF (59±2.5 years) and 22 age- and gender-matched healthy subjects (59.4±6.8 years) participated in the study. This study is a cross-sectional/comparison study. Balance was evaluated using the Activity-Specific Balance Confidence Scale (ABC) and the Mini-Balance Evaluation Systems Test (Mini-BESTest) balance battery, which includes the timed up-and-go test (TUG) and dual-task TUG. Gait analysis was performed using a Biodex Gait Trainer. Peripheral muscle strength (quadriceps muscle and handgrip strength) was assessed using a hand dynamometer and exercise capacity using the six-minute walk test (6MWT).

RESULTS

The CHF patients had significantly lower Mini-BESTest total, reactive postural control, and gait stability scores, significantly longer TUG/dual-task TUG time, and lower ABC score compared to the healthy control group (p<0.05). Chronic heart failure patients also showed significantly lower gait speed, stride length, gait cycle and step length (p<0.05). Dominant-side quadriceps muscle and handgrip strength and 6MWT distance were significantly reduced in CHF (p<0.05). Anticipatory postural adjustments and sensory orientation did not differ between groups.

CONCLUSIONS

Our study demonstrated impaired balance and gait performance and reduced muscle strength and exercise capacity in patients with CHF. Cardiac rehabilitation including balance and walking training should be planned for CHF patients to eliminate balance disorders, gait impairment and prevent falls in this patient group.

Investigating and defining outcomes of suprapatellar versus infrapatellar intramedullary nailing of tibial shaft fractures: a protocol for a pilot randomised controlled trial

Background

Anterior knee pain is often reported following intramedullary nailing of tibial shaft fractures. The aetiology remains unclear, but the surgical approach may play an important role. To date, no biomechanically validated method exists to assess patient outcomes specific to anterior knee pain in this cohort. The central aims of this study are to (1) evaluate the feasibility of a full-scale randomised controlled trial (RCT) investigating the influence of surgical approach on intramedullary nailing of tibial shaft fractures (suprapatellar versus infrapatellar nailing), (2) explore differences in clinical outcomes between the approaches, and (3) explore the development of a biomechanically validated methodology for assessing post-operative anterior knee pain and knee function specific to intramedullary nailing of tibial shaft fractures.

Methods

This pilot study will follow a prospective randomised controlled design at the Royal Adelaide Hospital and The Queen Elizabeth Hospital (South Australia). This study aims to recruit 60 patients between 18 and 60 years old who will be randomly assigned to either the suprapatellar or infrapatellar approach following a decision for intramedullary surgical fixation by the treating surgeon. All nails in this study will be Stryker T2 Alpha nails. Patients will undergo standard radiograph, magnetic resonance imaging, and clinical assessments in-line with their standard operative care, and complete a number of patient-reported and performance-based outcome measures. Performance-based outcome measures will be assessed utilising three-dimensional motion capture techniques. Follow-up time points are 3, 6, 12, and 18 months. Feasibility outcomes include ability to meet enrolment and retention metrics, compliance with all questionnaires and assessment procedures, and the occurrence of any adverse events. The primary clinical outcome is the incidence of anterior knee pain at 12 months after surgery.

Discussion

This study will establish the feasibility and inform the design of a large-scale RCT. Evaluation of all clinical data and patient outcomes will lead to the development of a new tool for assessing patient outcomes in this cohort. Limitations of the study include an unpredictable enrolment rate and loss to follow-up, small sample size, and the unknown ability of three-dimensional motion analysis to pick up the effects of anterior knee pain after tibial nailing.

Trial registration

This trial was prospectively registered on the 7 February 2020 on ANZCTR, ACTRN12620000109909.

Assessing isometric kicking force and post-match responses using the Kicker test

This study examined the inter-session reliability of force output from a novel isometric strength assessment protocol (the Kicker); and its suitability to monitor soccer player's combined hip flexion and knee extension force capacity over 72-h post-competitive matches. Reliability (Part-A) testing was completed over three sessions on 20 individuals participating in various sports at a recreational level or higher. Post-match strength response (Part-B) data were collected for 72-h after a game (24-h (+24), 48-h (+48) and 72-h (+72) post-match) in 17 male academy soccer players. After familiarisation, Kicker force for each limb showed high inter-session reliability (ICC >0.95; typical error <14 N, CV <6%); minimum detectable change at a 95% confidence interval <40 N). Across the 72-h post-match period, Kicker force for each limb was suppressed compared to baseline (force loss range = -5.8% to -12.5%; effect sizes range = -0.26 to -0.43) at all time points. The Kicker assessment protocol measures combined isometric hip flexor and knee extensor force capacity with high inter-session reliability. The proof of concept that the protocol can be used as a monitoring tool was evidenced by sustained suppression of baseline force capacity in both kicking limbs for 72-h post soccer matches.

Quadriceps and Hamstrings Strength Reference Values for Athletes With and Without Anterior Cruciate Ligament Reconstruction Who Play Popular Pivoting Sports, Including Soccer, Basketball, and Handball: A Scoping Review

OBJECTIVE

To synthesize and present reference values for quadriceps and hamstrings strength tests in healthy athletes who play pivoting sports and in athletes with anterior cruciate ligament reconstruction (ACLR) who play pivoting sports.

DESIGN

Scoping review.

LITERATURE SEARCH

We searched PubMed, the Cochrane Library, MEDLINE, Embase, and Web of Science up to January 26, 2021.

STUDY SELECTION CRITERIA

We included reference values in 2 different categories: (1) quadriceps and hamstrings strength test outcomes in healthy pivoting-sport athletes, and (2) quadriceps and hamstrings strength test outcomes in pivoting-sport athletes with ACLR at a specific time point during rehabilitation.

DATA SYNTHESIS

We performed a qualitative synthesis for reference values from isokinetic (at 60°/s, 180°/s, and 300°/s) and isometric quadriceps and hamstrings strength tests. We summarized the data for type of sport, sex, sport participation level, and age group.

RESULTS

Of the 42 included studies, 26 reported reference values from healthy soccer players, 4 from healthy basketball players, 4 from healthy handball players, and 11 from other healthy pivoting-sport athletes. The limb symmetry index dominant/nondominant limb (LSI-D/ND) ranged from 98% to 114% for healthy athletes. Six studies reported reference values in pivoting-sport athletes with ACLR at a specific time point during rehabilitation. After 7 months, strength values for athletes with ACLR were comparable to those of healthy pivoting-sport athletes.

CONCLUSION

This scoping review summarizes quadriceps and hamstrings strength reference values for athletes who play the most common pivoting sports, including soccer, basketball, and handball. J Orthop Sports Phys Ther 2022;52(3):142-155. Epub 31 Dec 2021. doi:10.2519/jospt.2022.10693.

Interrater and Intrarater Reliability of the EasyForce Dynamometer for Assessment of Maximal Shoulder, Knee and Hip Strength

This study aimed to determine the interrater and intrarater reliability of EasyForce dynamometer for assessing shoulder, knee, and hip muscle strength in healthy young adults. Shoulder, knee, and hip maximal isometric strength were measured using the EasyForce in healthy adults (11 women and 12 men). Three repetitions of shoulder internal rotation, abduction, knee flexion, extension, and hip abduction and adduction were performed. The tests were performed by three raters on the same day. The results showed good to high inter- and intrarater reliability (intraclass correlation coefficient range: 0.63–0.91). Moreover, the absolute reliability of the EasyForce was slightly higher than acceptable for all tests (CV > 10%) except for hip abduction on the right leg (CV = 7.2%). The EasyForce dynamometer can be considered a reliable tool for assessing shoulder internal rotation and abduction, knee extension and flexion, as well as hip abduction and adduction strength. The EasyForce dynamometer showed no differences between the raters’ measurements, which could be of great importance for professionals who want to perform the tests regardless of their strength on the values.

Should knee extension strength testing be implemented as a screening test for identifying probable and confirmed sarcopenia in older T2DM patients?

Background

The accelerated loss of muscle strength and mass observed in older type 2 diabetes mellitus (T2DM) patients due to the combined effects of diabetes and obesity, greatly increases their risk for sarcopenia. Early detection and treatment of probable and confirmed sarcopenia is paramount to delay mobility disability. Using low handgrip strength cut-off points for the initial identification of sarcopenia according to the new European Working Group on Sarcopenia in Older People (EWGSOP2) guidelines may mask the presence of sarcopenia. Relative knee extension strength cut-off points using a simple hand-held dynamometer can assist clinicians in the diagnosis of probable and confirmed sarcopenia by possibly reducing false negative results.

Methods

A cohort of one hundred T2DM older patients (60% women) (mean age 74.5 years) mostly obese community dwelling older adults were evaluated for body composition by Bioelectrical impedance analysis (BIA), yielding appendicular skeletal mass index (ASMI) results. Patients underwent handgrip strength (HGS) and knee extension strength (KES) tests as well as functional ability tests. Prevalence of probable and confirmed sarcopenia using HGS and KES cut-off points were calculated. Pearson correlations were performed to evaluate the relationship between ASMI and limbs strength. A regression analysis was conducted to examine which variables best predict ASMI values. A multivariate analysis of covariance was performed to assess the effect of independent variables on KES and HGS.

Results

Using cutoff points for low KES identified 24 patients with probable sarcopenia and two with confirmed sarcopenia. Conversely, using the EWGSOP2 cut off points for low HGS, identified only one patient with probable sarcopenia and none of the patients with confirmed sarcopenia.

Conclusion

KES cut-off points using a simple hand-held dynamometer can assist in the identification of probable and confirmed sarcopenia using EWGSOP2 cut off points for low muscle mass in a population of older T2DM patients for further analysis and early treatment. This is notably true in patients possessing high body mass index (BMI) alongside normal ASMI and HGS, potentially reducing false positive sarcopenia screening results.

Trial registration

ClinicalTrials.gov PRS: NCT03560375. Last registration date (last update): 06/06/2018. The trial was a-priori registered before actual recruitment of subjects.

Meeting movement quantity or quality return to sport criteria is associated with reduced second ACL injury rate

The purposes of this prospective cohort study were (1) to assess if second anterior cruciate ligament (ACL) injury rate 2 years after ACL reconstruction (ACLR) in those who returned to pivoting sport was associated with meeting (a) quantitative return to sport (RTS) criteria, (b) qualitative RTS criteria, and (c) combined quantitative and qualitative RTS criteria, and (2) to determine why athletes did not return to their preinjury (level of) sport. Athletes after ACLR performed RTS tests immediately before RTS: seven movement quantity (strength and hop test battery) and two movement quality (countermovement jump with LESS score and hop-and-hold test) tests. A 2-year postoperative questionnaire asked for RTS, reasons for not returning to the same (level of) sport and second ACL injuries. One hundred and forty-four athletes (82%) completed the questionnaire and 97 of them returned to a pivoting sport. Seven of these athletes had a second ACL injury. Meeting the hop test battery RTS criterion (absolute risk reduction 11%; p = .047) and hop-and-hold test RTS criterion (absolute risk reduction 15%; p = .031) were both significantly associated with a reduced second ACL injury rate. Meeting combined RTS criteria were not significantly associated with second ACL injury rate. Therefore, RTS tests after ACLR should at least comprise a hop test battery or the hop-and-hold test to reduce second ACL injury risk after return to pivoting sport. Also, one-third of all athletes mentioned fear of reinjury as the main reason for not returning to their preinjury (level of) sport. This psychological component should be taken seriously and discussed during rehabilitation.

Effect of a common exercise programme with an individualised progression criterion based on the measurement of neuromuscular capacity versus current best practice for lower limb tendinopathies (MaLaGa trial): a protocol for a randomised clinical trial

INTRODUCTION

High-load resistance training has shown positive effects in pain and function in lower limb tendinopathies. However, some authors suggest that current exercise programmes produce an increase in tolerance to load and exercise in general but without fixing some existing issues in tendinopathy. This may indicate the need to include training aspects not currently taken into account in the current programmes. The main objective of this study will be to compare the effect of a common exercise protocol for the three predominant lower limb tendinopathies (Achilles, patellar and gluteal), based on an individualised control of the dose and training of specific aspects of the neuromuscular system versus the current best practice for each location.

METHODS AND ANALYSIS

This study will be conducted among people with mid-portion Achilles, patellar or gluteal tendinopathy. The participants allocated to the experimental group will perform a 14-week innovative common therapeutic exercise programme. Participants allocated to the control group will carry out a 14-week exercise programme based on the best current practice for each of the studied locations. The Victorian Institute of Sports Assessment questionnaire will be considered the primary outcome. Pain, central sensitisation, fear avoidance behaviour, quality of life, treatment satisfaction, lower-limb strength and function, and high-density electromyography profile will be evaluated as secondary outcomes. Outcomes will be assessed at baseline, 7 weeks, after the intervention (week 14), 26 weeks and 52 weeks.

ETHICS AND DISSEMINATION

The study has been approved by the Portal de Ética de la Investigación Biomédica de Andalucía Ethics Committee (1221-N-19). All participants will be informed about the purpose and content of the study and written informed consent will be completed. The results of this study will be published in a peer-reviewed journal and will be disseminated electronically and in print.

TRIAL REGISTRATION NUMBER

NCT03853122; Pre-results.

CHANGES IN THE FLEXOR AND EXTENSOR MUSCLES AT DIFFERENT SPEEDS

ABSTRACT Introduction: Centrifugal strength is an important element for strength quality. Developing muscle centrifugal strength can effectively increase the stability of lower limbs and reduce the risk of injury. Objective: To explore the characteristics of contractile force of flexor ahods in strength training and rehabilitation training, and the extensor muscles of the knee joint in athletes with different speeds of centripetal force. Methods: The knee joint muscle group of 8 first-level male high jumpers and 8 second-level male high jumpers were tested by isokinetic centrifugal contraction; the angular test velocity was 60 °/s, 120 °/s, 240 °/s, and the indexes included peak torque, relative peak torque (peak torque/body weight), and the peak torque flexural extension ratio. Results: With the centrifugal contraction of the knee joint muscle group (P < 0.05), the second-level high jumpers should increase the ability of the knee flexor muscle group of the take-off leg. In the case of constant velocity centrifugal contraction (P < 0.01), taking off time must be reduced, that is, taking off speed must be accelerated. Conclusions: The difference in the knee joint muscle isokinetic test results is one of the reasons for the difference in knee joint flexor and extensor muscle contractility under the different speed forces of high jumpers. Level of evidence II; Therapeutic studies - investigation of treatment results.

Strength and endurance deficits in adults with moderate-to-severe hip osteoarthritis, compared to healthy, older adults

PURPOSE

This study compares lower limb muscle strength and endurance in adults with hip osteoarthritis, to an age-matched control group.

METHODS

Thirteen adults with moderate-to-severe hip osteoarthritis (as graded by the Oxford Hip Score) and fifteen older adults participated. Maximal voluntary isometric contraction of the knee extensors, knee flexors and hip abductors and isotonic endurance of the knee extensors were measured using a dynamometer. Function was assessed using the 30-second chair stand test, the 40 m fast-paced walk test and a stair negotiation test. Data were compared between groups using t-tests.

RESULTS

Participants with hip osteoarthritis demonstrated weakness in the affected limb when compared to the control limb during knee flexion (34%, p = 0.004) and hip abduction (46%, p = 0.001). Weakness was also observed in the contralateral knee flexors (31%, p = 0.01). When compared to the control limb, the knee extensors of the hip osteoarthritis group were exhausted prematurely in the affected (70%, p = 0.001) and contralateral limb (62%, p = 0.005). The hip osteoarthritis group took twice as long to stair climb (p = 0.002), walked 40% slower, (p < 0.001), and had a 35% lower sit-stand performance (p < 0.001).

CONCLUSIONS

Moderate-to-severe hip osteoarthritis may be characterised by bilateral deficits in lower-limb maximal strength, markedly lower knee extensor endurance and impaired functional performance.Implications for rehabilitationIn addition to bilateral deficits in maximal strength of the hip and knee muscles, moderate-to-severe hip osteoarthritis may be characterised by markedly lower muscular endurance of the knee extensors and impaired functional performance.The endurance capacity of the knee extensors can play an important role in daily function, and thus it is important to consider endurance training principles when prescribing exercise for this patient group.Research studies evaluating exercise programmes underpinned by endurance training principles are required to understand the benefits to patients with hip osteoarthritis, and to inform specific exercise prescription in clinical practice.

Quadriceps Strength After Anterior Cruciate Ligament Reconstruction Compared With Uninjured Matched Controls: A Systematic Review and Meta-analysis

Background:

The limb symmetry index may overestimate the recovery of quadriceps muscle strength after anterior cruciate ligament reconstruction. Comparison of individuals who have had anterior cruciate ligament reconstruction with age-, sex-, and activity-matched individuals might be more appropriate to guide rehabilitation interventions.

Purpose:

To compare the quadriceps strength between the injured limb of people with anterior cruciate ligament reconstruction and the limb of an age-, sex-, and activity-matched control group.

Study Design:

Systematic review; Level of evidence, 3.

Methods:

MEDLINE, CINAHL, EMBASE, SCOPUS, and SPORTDiscus were searched between inception and April 2019. Studies were included if they reported the peak quadriceps strength for persons with anterior cruciate ligament reconstruction and age-, sex-, and activity-matched control groups measured using isometric or isokinetic dynamometry. Risk of bias was assessed, and meta-analyses and metaregression (for effect of time since surgery) were performed.

Results:

A total of 2759 studies were identified and 21 were included for analyses. Quadriceps strength was lower in the limbs with anterior cruciate ligament reconstruction compared with the limb from matched controls within 6 months of anterior cruciate ligament reconstruction (standardized mean difference [SMD], –1.42; 95% CI, –1.62 to –1.23), 6 to 18 months after anterior cruciate ligament reconstruction (SMD, –0.92; 95% CI, –1.18 to –0.66), and >18 to 48 months after anterior cruciate ligament reconstruction (SMD, –0.38; 95% CI, –0.79 to 0.03). Results of the metaregression were significant, with the difference between anterior cruciate ligament reconstruction and matched controls decreasing with time since surgery (P < .001).

Conclusion:

In people with anterior cruciate ligament reconstruction, the injured limb had lower quadriceps strength compared with the limb of age-, sex-, and activity-matched controls up to 4 years after surgery. Clinicians should consider comparison with matched cohorts for return to sports decision making.

Comparison of Common Methodologies for the Determination of Knee Flexor Muscle Strength

BACKGROUND

Knee flexion strength may hold important clinical implications for the determination of injury risk and readiness to return to sport following injury and orthopedic surgery. A wide array of testing methodologies and positioning options are available that require validation prior to clinical integration. The purpose of this study was to 1) investigate the validity and test-retest reliability of isometric knee flexion strength measured by a fixed handheld dynamometer (HHD) apparatus compared to a Biodex Dynamometer (BD), 2) determine the impact of body position (seated versus supine) and foot position (plantar- vs dorsiflexed) on knee flexion peak torque and 3) establish the validity and test-retest reliability of the NordBord Hamstring Dynamometer.

STUDY DESIGN

Validity and reliability study, test-retest design.

METHODS

Forty-four healthy participants (aged 27 ± 4.8 years) were assessed by two raters over two testing sessions separated by three to seven days. Maximal isometric knee flexion in the seated and supine position at 90o knee flexion was measured with both a BD and an externally fixed HHD with the foot held in maximal dorsiflexion or in plantar flexion. The validity and test-retest reliability of eccentric knee flexor strength on the NordBord hamstring dynamometer was assessed and compared with isometric strength on the BD.

RESULTS

Level of agreement between HHD and BD torque demonstrated low bias (bias -0.33 Nm, SD of bias 13.5 Nm; 95% LOA 26.13 Nm, -26.79 Nm). Interrater reliability of the HHD was high, varying slightly with body position (ICC range 0.9-0.97, n=44). Isometric knee flexion torque was higher in the seated versus supine position and with the foot dorsiflexed versus plantarflexed. Eccentric knee flexion torque had a high degree of correlation with isometric knee flexion torque as measured via the BD (r=0.61-0.86). The NordBord had high test-retest reliability (0.993 (95%CI 0.983-0.997, n=19) for eccentric knee flexor strength, with an MDC95 of 26.88 N and 28.76 N for the left and right limbs respectively.

CONCLUSION

Common measures of maximal isometric knee flexion display high levels of correlation and test-retest reliability. However, values obtained by an externally fixed HHD are not interchangeable with values obtained via the BD. Foot and body position should be considered and controlled during testing.

LEVEL OF EVIDENCE

2b.

Assessing the Reliability of Handheld Dynamometry and Ultrasonography to Measure Quadriceps Strength and Muscle Thickness in Children, Adolescents, and Young Adults

Aims: Muscle strength testing is a core aspect in the pediatric physical and occupational therapy clinical examination and evaluation, and quadriceps muscle strength is associated with the ability to perform gross motor skills. The aim of this study was to assess the reliability of handheld dyamometry (HHD) and ultrasonography to measure quadriceps muscle strength and thickness in children, adolescents, and young adults. Methods: In 30 participants (6-26 years), without motor impairment, quadriceps strength was measured with HHD in seated and supine with the knee flexed to 90° and 35°. Rectus femoris (RF) and vastus lateralis (VL) muscle thickness was measured using ultrasonography. Typical error of measurement (TEM), coefficient of variation (CV%), and intra-class correlation coefficient (ICC) were used to assess the error and reliability of measures. Results: The average CV% among three trials of strength testing was 7.07%-9.94% and improved when using the top two trials (4.49%-5.61%). The average TEM was 2.21 Nm for strength and 0.03 cm for muscle thickness. Intra-rater and inter-rater reliability of muscle thickness was good to excellent (0.91-1.00).Conclusions: The results of this study suggest quadriceps muscle strength and thickness measurements using HHD and ultrasonography are reliable in children, adolescents, and young adults.

Real-time measurement of isometric peak torque and rate of torque development using a novel strength testing device: a validity and reliability study

Objective: Isometric peak torque (PT) and rate of torque development (RTD) are important characteristics relevant to athletic performance. A novel device called the Dynamo Torque Analyzer calculates and displays real-time measurements of isometric PT and RTD. However, the ability of the Dynamo to provide valid and reliable isometric PT and RTD measurements similar to those of an isokinetic dynamometer remains unclear. This study aimed to compare the reliability and magnitude of isometric leg extension and flexion PT and RTD measurements between an isokinetic dynamometer and the Dynamo Torque Analyzer.Approach: Twenty healthy, recreationally-active adults (age = 22 ± 3 years; height = 169 ± 10 cm; mass = 71 ± 18 kg) performed three isometric leg extension and flexion maximal voluntary contractions on two different occasions, from which isometric PT and early (RTD100), late (RTD200), and maximum (Peak RTD) RTD characteristics were measured by an isokinetic dynamometer and the Dynamo.Main results: Isometric leg extension and flexion PT and RTD characteristics were highly consistent across sessions for both the isokinetic dynamometer and Dynamo devices, with intraclass correlation coefficients of 0.935-0.984 and standard errors of measurement expressed as a percentage of the mean of 4.93-14.46%. There were significant positive relationships between the isokinetic dynamometer and Dynamo for all PT and RTD characteristics (r≥ 0.994;P< 0.001). Moreover, no significant differences between devices were observed for these variables (P= 0.107-0.555).Significance: These findings suggest that the Dynamo Torque Analyzer may be a valid and reliable device for measuring isometric PT and RTD of the lower-body musculature.

LESS THAN HALF OF ACL-RECONSTRUCTED ATHLETES ARE CLEARED FOR RETURN TO PLAY BASED ON PRACTICE GUIDELINE CRITERIA: RESULTS FROM A PROSPECTIVE COHORT STUDY

Background

A recently published Dutch practice guideline emphasizes criterion-based rehabilitation after anterior cruciate ligament reconstruction (ACLR) instead of time-based. As a consequence of this criterion-based rehabilitation, return to play is only suggested when athletes meet specific return to play (RTP) criteria.

Purpose

The goal of this prospective observational study was to analyze if physical therapists adhere to ACLR practice guideline RTP criteria for testing and return to sport decisions, and to explore whether there is a difference in adherence between physical therapists specialized in sports versus those who are not.

Methods

When the treating physical therapist cleared an athlete for RTP after ACLR, the primary researcher performed RTP measurements according to the ACLR practice guideline to investigate if all nine quantitative and qualitative RTP criteria were met.

Results

Of the 158 athletes (54 females and 104 males, mean age 24 ± 6 years, 12 ± 3 months after surgery), 69 (44%) had performed the RTP measurements with their primary physical therapist. Of the athletes tested by their primary physical therapist 23% met all RTP criteria compared to 10% of the athletes who were not tested at all by their primary physical therapist (p = 0.026). Of the athletes rehabilitating with a sports physical therapist, 52% had been tested by their primary physical therapist compared to 34% of the athletes rehabilitating with a non-sports physical therapist (p = 0.024).

Conclusion

Only 44% of the athletes were tested according to the guideline RTP criteria and only 23% of them were given an RTP advice consistent with the ACLR guideline. Although sports physical therapists adhered to the guideline more often than non-sports physical therapists, the adherence is still alarmingly low. More attention for the implementation of ACLR guidelines and RTP criteria is needed.

Level of evidence

Therapy, level 2b.

High-intensity downhill running exacerbates heart rate and muscular fatigue in trail runners

This study explores the cardiorespiratory and muscular fatigue responses to downhill (DR) vs uphill running (UR) at similar running speed or similar oxygen uptake (⩒O₂). Eight well-trained, male, trail runners completed a maximal level incremental test and three 15-min treadmill running trials at ±15% slope: i) DR at ~6 km·h^-1 and ~19% ⩒O_2max (LDR); ii) UR at ~6 km·h^-1 and ~70% ⩒O_2max (HUR); iii) DR at ~19 km·h^-1 and ~70% ⩒O_2max (HDR). Cardiorespiratory responses and spatiotemporal gait parameters were measured continuously. Maximal isometric torque was assessed before and after each trial for hip and knee extensors and plantar flexor muscles. At similar speed (~6 km·h^-1), cardiorespiratory responses were attenuated in LDR vs HUR with altered running kinematics (all p < 0.05). At similar ⩒O₂ (~3 l·min^-1), heart rate, pulmonary ventilation and breathing frequency were exacerbated in HDR vs HUR (p < 0.01), with reduced torque in knee (-15%) and hip (-11%) extensors and altered spatiotemporal gait parameters (all p < 0.01). Despite submaximal metabolic intensity (70% ⩒O_2max), heart rate and respiratory frequency reached maximal values in HDR. These results further our understanding of the particular cardiorespiratory and muscular fatigue responses to DR and provide the bases for future DR training programs for trail runners.

Association of SARC-F Questionnaire and Mortality in Prevalent Hemodialysis Patients

Sarcopenia is common in patients undergoing chronic hemodialysis, which leads to poor outcomes. SARC-F (sluggishness, assistance in walking, rising from a chair, climb stairs, falls), a self-report questionnaire, is recommended as an easily applied tool for screening sarcopenia in older people. However, there are limited data regarding its use in patients undergoing chronic hemodialysis. Therefore, we aimed to evaluate the association between SARC-F and mortality in these patients. SARC-F questionnaire was applied in 271 hemodialysis patients (mean age 64.4 ± 14.3 years) at baseline. The association between SARC-F and mortality during a 24-month follow-up was analyzed. During this follow-up period, 40 patients (14.8%) died. The discriminative power of SARC-F score for predicting mortality was 0.716 (95% confidence interval (CI) = 0.659–0.769; p < 0.001). The best cut-off was a score ≥1, which provided 85.0% sensitivity, 47.2% specificity, 21.8% positive predictive value, and 94.8% negative predictive value. Kaplan–Meier curves showed that patients with SARC-F ≥ 1 exhibited a higher risk of mortality than those with SARC-F < 1 (p < 0.001). Moreover, a stepwise decline in survival with higher SARC-F scores was also observed. After full adjustments, SARC-F ≥ 1 was independently associated with increased mortality (hazard ratio = 2.87, 95% CI = 1.11–7.38; p = 0.029). In conclusion, SARC-F applied for sarcopenia screening predicted mortality in patients undergoing chronic hemodialysis.

Limited Support for Trunk and Hip Deficits as Risk Factors for Athletic Knee Injuries: A Systematic Review With Meta-analysis and Best-Evidence Synthesis

OBJECTIVE

To determine whether neuromuscular deficits in trunk and hip-related function are risk factors for athletic knee injuries.

DESIGN

Etiology systematic review with meta-analysis.

LITERATURE SEARCH

Six online databases (MEDLINE, Web of Science, Embase, CINAHL, Scopus, and SPORTDiscus) were searched up to April 2019.

STUDY SELECTION CRITERIA

Studies assessing trunk and hip neuromuscular function as risk factors for knee injuries in healthy athletic populations were included.

DATA SYNTHESIS

Outcomes were synthesized quantitatively using meta-analysis of odds ratios, and qualitatively using best-evidence synthesis.

RESULTS

Twenty-one studies met the inclusion criteria. There was very low-certainty evidence that greater hip external rotation strength protected against knee injuries (odds ratio = 0.78; 95% confidence interval: 0.70, 0.87; P<.05). There was limited evidence that deficits in trunk proprioception and neuromuscular control, and the combination of excessive knee valgus and ipsilateral trunk angle when landing unilaterally from a jump, may be risk factors for knee injuries.

CONCLUSION

Most variables of trunk and hip function were not risk factors for injuries. Further research is required to confirm whether hip external rotation strength, trunk proprioception and neuromuscular control, and the combination of knee valgus angle and ipsilateral trunk control are risk factors for future knee injuries. J Orthop Sports Phys Ther 2020;50(9):476-489. Epub 1 Aug 2020. doi:10.2519/jospt.2020.9705.

Validity and reliability of isometric knee extension muscle strength measurements using a belt-stabilized hand-held dynamometer: a comparison with the measurement using an isokinetic dynamometer in a sitting posture

[Purpose] This study aimed to determine the validity and reliability of isometric knee extension muscle strength measurements using a belt-stabilized hand-held dynamometer compared to that using an isokinetic dynamometer with the participant in a sitting posture. [Participants and Methods] Forty-two university students participated. The isometric knee extension muscle strength was measured using a hand-held dynamometer and an isokinetic dynamometer. For both measurements, the participants were in the similar sitting posture. The sitting posture maintained trunk stability, with the hands on the bed, and the non-measurement-side toe touching the floor or table. The intra-class correlation coefficient and the relevance were verified. [Results] Intra-rater correlation coefficient (1, 1) of the two measurements was ≥0.75. A significant difference was found in the measurement value between males and females. No significant difference was found between the measurements value of the two devices. A significant positive correlation was found in the measurement value of two devices in the male participants. [Conclusion] When compared to the standard method of isometric knee extension muscle strength measurements using an isokinetic dynamometer with the participant in the sitting posture, measurements using the belt-stabilized hand-held dynamometer were considered valid and highly reliable in the male participants.

The Tolerability and Efficacy of 4 mA Transcranial Direct Current Stimulation on Leg Muscle Fatigability

Transcranial direct current stimulation (tDCS) modulates cortical excitability and affects a variety of outcomes. tDCS at intensities ≤2 mA is well-tolerated, but the tolerability and efficacy of tDCS at intensities >2 mA merits systematic investigation. The study objective was to determine the tolerability and effects of 4 mA tDCS on leg muscle fatigability. Thirty-one young, healthy adults underwent two randomly ordered tDCS conditions (sham, 4 mA) applied before and during an isokinetic fatigue test of the knee extensors and flexors. Subjects reported the severity of the sensations felt from tDCS. Primary outcomes were sensation tolerability and the fatigue index of the knee extensors and flexors. A repeated-measures ANOVA determined statistical significance (p < 0.05). Sensation severity at 4 mA tDCS was not substantially different than sham. However, two subjects reported a moderate–severe headache, which dissipated soon after the stimulation ended. The left knee flexors had significantly greater fatigability with 4 mA tDCS compared with sham (p = 0.018). tDCS at 4 mA was well-tolerated by young, healthy subjects and increased left knee flexor fatigability. Exploration of higher intensity tDCS (>2 mA) to determine the potential benefits of increasing intensity, especially in clinical populations with decreased brain activity/excitability, is warranted.

Hand-held dynamometer identifies asymmetries in torque of the quadriceps muscle after anterior cruciate ligament reconstruction

PURPOSE

To verify the validity and diagnostic accuracy of the hand-held dynamometer (HHD) with the isokinetic dynamometer for evaluating the quadriceps strength of subjects who have undergone ACL reconstruction (ACLR).

METHODS

This validity and diagnostic accuracy study was conducted prospectively by examining 70 consecutive participants who had undergone ACLR at least 6 months previously. All participants performed strength evaluation of the quadriceps muscle using the HHD and isokinetic dynamometer.

RESULTS

The HHD presented high test-retest reliability [intraclass correlation coefficient (ICC) = 0.98], moderate to good validity with the isokinetic dynamometer when compared for the quadriceps strength (r = 0.62), 100% perfect specificity [LR + infinity, 95% confidence interval (CI) 81.4%-100%] to identify those with LSI > 10%, and a sensitivity of 63.4% (48.9%-76.3%).

CONCLUSION

The HHD is an instrument valid and reliable of low cost and easy handling compared to the isokinetic dynamometer to evaluate the quadriceps torque and the limb symmetry index after the ACLR with high diagnostic accuracy.

LEVEL OF EVIDENCE

I.

Força muscular e habilidade de locomoção em indivíduos pós-acidente vascular encefálico crônico

RESUMO O objetivo do estudo foi verificar se existem diferenças na força muscular dos membros inferiores (MMII) e na habilidade de locomoção de indivíduos pós-acidente vascular encefálico (AVE) crônico, classificados como deambuladores comunitários ou não comunitários. Foi realizado um estudo transversal em 60 indivíduos pós-AVE crônico, divididos em deambuladores comunitários (n=33) e não comunitários (n=27) pela velocidade de marcha. A força muscular de sete grupos musculares bilaterais de MMII foi avaliada por meio do teste do esfigmomanômetro modificado e habilidade de locomoção pelo ABILOCO. Estatísticas descritivas foram utilizadas para caracterizar a amostra, e o teste t de Student para amostras independentes, a fim de comparar os dois grupos de indivíduos pós-AVE. Observou-se que os deambuladores comunitários apresentaram maiores valores de força muscular para a maioria dos grupos musculares de MMII (−0,973≥t≥−3,189; p≤0,04), e na habilidade de locomoção (t=−2,841; p=0,006). Os indivíduos pós-AVE crônico deambuladores comunitários possuem maior força muscular de MMII e mais habilidade de locomoção em comparação aos deambuladores não comunitários. Sugere-se que a avaliação fisioterapêutica de indivíduos pós-AVE inclua, além da mensuração da força muscular de MMII e seu tratamento, a mensuração da percepção da habilidade de locomoção, para análises da evolução do paciente e da eficácia da conduta terapêutica.

Different strength declines in leg primary movers versus stabilizers across age-Implications for the risk of falls in older adults?

This study investigated differences in the declines of isometric strength in hip abductors and adductors versus knee extensors across four different age groups (n = 31: 11.2 ± 1.0 y, n = 30: 23.1 ± 2.7 y, n = 27: 48.9 ± 4.4 y, and n = 33: 70.1 ± 4.2 y) with a total of 121 female subjects. As a starting point, we assumed that, during their daily activities, elderly people would use their leg stabilizers less frequently than their leg primary movers as compared to younger people. Given that muscle strength decreases in the course of the aging process, we hypothesized that larger strength declines in hip abductors and hip adductors as compared to knee extensors would be detected across age. Maximal isometric force for these muscle groups was assessed with a digital hand-held dynamometer. Measurements were taken at 75% of the thigh or shank length and expressed relative to body weight and lever arm length. Intratester reliability of the normalized maximal torques was estimated by using Cronbach’s alpha and calculated to be larger than 0.95. The obtained results indicate a clearly more pronounced strength decline in hip abductors and hip adductors across age than in the knee extensors. Therefore, a particular need for strength training of the lower extremity stabilizer muscles during the aging process is implied.

Exercise training increases skeletal muscle strength independent of hypertrophy in older adults aged 75 years and older

AIM

We investigated whether exercise-mediated acquisition of muscle mass and strength would occur in a concurrent manner in older adults.

METHODS

A total of 152 community-dwelling older adults (young-old aged 65-74 years, old-old aged >75 years) were allocated into either 8-week comprehensive exercise training or the control group. Participants (n = 136) completed all pre- and post-intervention testing visits (young-old n = 73, old-old n = 63). Older adults in exercise groups were subjected to a series of programmed elastic band and free exercises twice per week at three to five sets of 15-20 repetitions. Body composition, skeletal muscle mass, knee strength (extensors and flexors) and gait-related physical function were evaluated as main variables.

RESULTS

As expected, muscular mass and knee strength (both extensors and flexors) were inversely correlated with age in the old-old group (all P < 0.001). However, knee extensor strength was the only lower limb component inversely correlated with age in the young-old group (P < 0.043). Knee extensor strength was significantly increased by exercise training in both the young-old and old-old groups (young old P < 0.042, old-old P < 0.011). Training-induced muscle hypertrophy was observed only in the young-old group (P < 0.025). the correlation of knee extensor strength against gait-related physical function was the greatest, followed by knee flexor strength and muscle mass.

CONCLUSIONS

The present results showed that age-associated strength decline of the knee extensor occurs earlier compared with the knee flexor during the aging process, and exercise training increases muscular strength without significant changes of muscle mass in older adults aged aged ≥75 years. Geriatr Gerontol Int 2019; 19: 265-270.

Physical Frailty and Cognitive Functioning in Korea Rural Community-Dwelling Older Adults

Cognitive frailty is a heterogeneous clinical manifestation characterized by the simultaneous presence of physical frailty and cognitive impairment. The objective of this study was to investigate the association between physical frailty and cognitive function in rural community-dwelling older Korean adults, taking four cognitive domains into account. We carried out a cross-sectional population-based study which enrolled 104 community-dwelling elderly. Physical frailty phenotype, as well as its individual criteria, were used. Cognitive functioning was examined in the four domains of memory, processing speed, cognitive flexibility, and working memory. Demographic data, lipid profile, muscle strength, physical function, and 25-hydroxyvitamin D (25[OH]D) concentration collected from questionnaire interviews and assessments were included. Of the 104 older adults (77% female), 24.3% were classified as robust, 49.6% as prefrail, and 16.5% as frail. Linear regression analyses showed that the severity of frailty index was associated with four cognitive domains Muscle strength (i.e., Grip strength, Knee extensor and flexor), physical function (i.e., SPPB and Gait speed), and 25[OH]D were associated with poorer cognitive function. Within our population of Korean rural community-dwelling older adults, physical frailty status, muscle strength, physical functions, and biochemical measurements were associated with poorer cognitive function. Synchronicity of physical frailty and cognitive dysfunction may contribute to the negative health-related effects associated with aging.

Postoperative rehabilitation of simultaneous rupture of anterior cruciate ligament and patellar ligament: A case report

INTRODUCTION

The simultaneous rupture of anterior cruciate ligament (ACL) and patellar ligament (PL) is an infrequent condition. Each isolated injury has surgical techniques and rehabilitation protocols that differ widely among each other. Nonetheless, there is no established physical rehabilitation approach when both injuries are associated.

OBJECTIVE

The aim of this report is to describe the rehabilitation and the outcomes obtained in the postoperative period of simultaneous rupture of ACL and PL and the follow-up period.

CASE REPORT

A 21-year-old male patient suffered the rupture of ACL and PL after landing from a jump while playing soccer. The knee was immediately immobilized, and 10 weeks later, he was operated in a one-stage surgery. He initiated his rehabilitation 3 weeks after the surgical resolution. A three-times a week rehabilitation was implemented to restore range of motion and improve functional status. An extensive evaluation was carried out monthly using dynamic neuromuscular tests and self-reported questionnaires.

RESULTS

At the end of the rehabilitation, he presented a complete extension and 130° of knee flexion in passive open kinetic chain. The Single Leg Squat and Landing Error Scoring System showed a good performance, while the Star Excursion Balance Test and the single hops assessments were symmetrical. The International Knee Documentation Committee and Lower Extremity Functional Scale questionnaires yielded values of 90.8% and 77 points, respectively.

CONCLUSION

An approach based on mobility exercises and strengthening of the lower limbs and the core muscles, considering the biological healing times of each particular structure, made it possible to obtain satisfactory results in mobility, functional tests, self-reported questionnaires, and patient's satisfaction.

Associations among knee muscle strength, structural damage, and pain and mobility in individuals with osteoarthritis and symptomatic meniscal tear

Background

Sufficient lower extremity muscle strength is necessary for performing functional tasks, and individuals with knee osteoarthritis demonstrate thigh muscle weakness compared to controls. It has been suggested that lower muscle strength is associated with a variety of clinical features including pain, mobility, and functional performance, yet these relationships have not been fully explored in patients with symptomatic meniscal tear in addition to knee osteoarthritis. Our purpose was to evaluate the associations of quadriceps and hamstrings muscle strength with structural damage and clinical features in individuals with knee osteoarthritis and symptomatic meniscal tear.

Methods

We performed a cross-sectional study using baseline data from the Meniscal Tear in Osteoarthritis Research (MeTeOR) trial. We assessed structural damage using Kellgren-Lawrence grade and the magnetic resonance imaging osteoarthritis knee score (MOAKS) for cartilage damage. We used the Knee Injury and Osteoarthritis Outcomes Score (KOOS) to evaluate pain, symptoms, and activities of daily living (ADL), and the Timed Up and Go (TUG) test to assess mobility. We assessed quadriceps and hamstrings strength using a hand-held dynamometer and classified each into quartiles (Q). We used Chi square tests to evaluate the association between strength and structural damage; and separate analysis of covariance models to establish the association between pain, symptoms, ADL and mobility with strength, after adjusting for demographic characteristics (age, sex and BMI) and structural damage.

Results

Two hundred fifty two participants were evaluated. For quadriceps strength, subjects in the strongest quartile scored 14 and 13 points higher on the KOOS Pain and ADL subscales, respectively, and completed the TUG two seconds faster than subjects in the weakest quartile. For hamstrings strength, subjects in the strongest quartile scored 13 and 14 points higher on the KOOS pain and ADL subscales, respectively, and completed the TUG two seconds faster than subjects in the weakest quartile. Strength was not associated with structural damage.

Conclusions

Greater quadriceps and hamstrings muscle strength was associated with less pain, less difficulty completing activities of daily living, and better mobility. These relationships should be evaluated longitudinally.

Association between knee extensor strength and pulmonary function in the female elderly

[Purpose] The purpose of this study is to study the impact of knee extensor strength, which is an index of the degree of physical activity on lung capacity in older women. [Subjects and Methods] Thirty-three older women who participated in the exercise program hosted by a senior citizen center and S University located in Busan. Force vital capacity (FVC) was measured with digital spirometry (Pony FX, COSMED Inc., Italy). Three rounds of measurements were taken for each participant, with one-minute rests between the tests. The means were computed for analysis. Knee extensor strength was measured with a hand-held dynamometer (HHD, MicroFET2^®, Hogan Health Industries, Inc., UT, USA). Three rounds of measurements were taken for each knee extensor muscle, after which the mean of the measurements was taken for each side. The higher knee extensor muscle strength value was used for the analysis. [Results] Knee extensor muscle strength had significant positive correlations with Forced vital capacity (FVC), Forced expiratory volume in 1 second (FEV₁), Peak expiratory flow (PEF), and Forced expiratory flow (FEF 25–75%). Association between knee extensor muscle strength and pulmonary function suggested that weakening of the elderly’s knee extensor muscle strength has an adverse effect on pulmonary function, although the explanatory power was weak. [Conclusion] Knee extensor muscle weakness in elderly females restricts their physical activity and mobility, thereby serving as a key factor in decreasing their lung capacity.

Effects of Whole Body Vibration on Muscle Strength and Quality of Life in Health Elderly: A Meta-Analysis

Abstract Introduction: The literature presents different findings about the vibration training efficacy on muscle per- formance, even using protocols with similar parameters. Objective: The purpose of this systematic review was to investigate the effects of whole body vibration (WBV) on strength and quality of life in health elderly people, presenting a meta-analisys. Methods: PubMed, CINAHL, SciELO, LILACS and PEDro databases were systematically searched for studies that used WBV in healthy elderly. These searches were supplemented with material identified in references and a qualitative and quantitative analysis was performed to sum- marize the findings. The search was performed by two independent researchers with a third was selected to solve problems of search disagreement, data collection, and quality score. Results: Nine studies with strength outcome and two studies with quality of life outcome were identified, with sample ranging 21 to 220 elderly, all studies had control groups performing exercises or guidelines. Some studies have shown sig- nificant improvements in muscle strength, muscle power, vertical jump height, timed get up and go test and quality of life. Conclusion: The meta-analysis of the findings in these studies shows that WBV could benefit health elderly, increasing muscle strength and improving the quality of life mainly in functional capacity. The number of publications found in the databanks searched is small, with limitations in design of protocols with a weakness to the interpretation of the findings, suggesting the need of investigation with WBV with well-designed protocols and controlled parameters into the effects of WBV training in elderly people.