Effect of physical exercise and age on knee joint position sense

Effects of Pilates Exercise Training on Static Balance and Lower Limbs Proprioception in Adult Females With and Without Flexible Flatfeet

BACKGROUND

It is well known that flatfeet are associated with a higher incidence of lower limb injuries in different populations. Thus, we examine how Pilates exercise training affects static balance and ankle and knee proprioception in females with and without flexible flatfeet. Study Design. Case series; Level of evidence.

METHODS

This quasi-experimental study involves 91 healthy 18- to 25-year-old female university students. The Navicular Drop Test was used to diagnose flatfeet. Pilates included core strength, balance, and flexibility exercises for 16 weeks. Static balance was assessed using the sharpened Romberg test and ankle and knee joint proprioception were measured using joint position reproduction tests. The Wilcoxon test indicated within-group pre-post improvements in static balance, and ankle and knee joint proprioception in the Pilates and the healthy control group (P < .05).

RESULTS

The between-group comparisons at post-test showed significant differences for joint position reproduction test of the dorsiflexion (P < .05, η2 = 0.10) and the plantarflexion (P < 0.05, η2 = 0.08) in favor of the healthy controls group. Joint proprioception of ankle and knee was positively correlated with increasing static balance in the healthy control group.

CONCLUSION

The results showed that Pilates has the potential to improve static balance, and ankle and knee proprioception. However, it did not improve postural control and proprioception in individuals with flatfeet. Our findings advise combining Pilates with other interventions to develop flexible flatfeet in females.

LEVELS OF EVIDENCE

Level I.

Acute and Acclimated Effects of Wearing Compression Garments on Balance Control in Community-Dwelling Older Adults

Falls are very serious health concerns among older adults. Providing additional cutaneous and proprioceptive feedback to older adults may enhance their balance control and therefore reduce the incidents of falls. This study aimed to investigate the acute and acclimated effect of wearing waist-to-above-ankle compression garments (CGs) on balance control in community-dwelling older adults. Thirty-one older adults participated in the study. The Timed Up and Go, Berg Balance Scale, and the Fall Risk Test of the Biodex Balance System were used in a random order to examine balance control in three testing sessions 1 week apart. Results indicated wearing CGs had a significant impact on the Timed Up and Go test (p < .001), Berg Balance Scale (p = .001), and the Fall Risk Test (p = .001). For the Timed Up and Go test, participants exhibited significant improvement in both the acute (8.68 vs. 7.91 s) and acclimated effect (7.91 vs. 7.41 s) of wearing CGs. For the Berg Balance Scale, participants showed significant improvement after wearing CGs for 1 week in comparison to the no CGs condition (55.77 vs. 55.39 points). For the Fall Risk Test, participants showed a significant improvement in the acute effect of wearing CGs in comparison to the no CGs condition (1.55° vs. 1.31°). This exploratory study showed that wearing waist-to-above-ankle CGs provided a positive impact on balance control in healthy community-dwelling older adults. It lays the foundation for future studies with a larger sample size to investigate the potential benefits of wearing CGs in individuals with balance control deficits and/or other comorbidities.

Effectiveness of a sensorimotor exercise program on proprioception, balance, muscle strength, functional mobility and risk of falls in older people

Introduction

Sensory systems provide the necessary information for a motor response to be provided. In this sense, the objective of this study is to evaluate the effectiveness of a sensorimotor exercise program on proprioceptive acuity, balance, muscle strength, functional mobility and risk of falls in institutionalized elderly.

Methodology

56 participants (84.6 ± 8.4 years) were randomly distributed between the control (CG, n = 28) and intervention groups (IG, n = 28). The CG performed a protocol based on warm-up, muscle strengthening and warm down and the IG performed the same intervention, with the addition of sensorimotor exercises. Joint Position Sensation (JPS) was evaluated in both limbs at angles of 20° and 45°, balance, functional mobility, fear of falling in the elderly and muscle strength of quadriceps, hamstrings, adductors and abductors in both limbs, before and after the 12 weeks of intervention.

Results

Both groups showed gains in muscle strength. When analyzing functionality through Timed Up and Go (TUG), before and after for each group separately, both showed a significant difference (CG p = 0.002; IG p < 0.001). For the Short Physical Performance Battery (SPPB) variable, there were significant differences in IG in balance (p < 0.001), gait speed time (s) (p = 0.004) and sit-to-stand (p = 0.002). In JPS, significant differences were recorded for Absolute Error 45° Non-Dominant (p = 0.045) and Relative Error 45° Non-Dominant (p = 0.045) in the CG and Relative Error 45° Non-Dominant for IG (p = 0.018). In the Falls Efficacy Scale International (FES-I) variable there were significant improvements in the CG (p = 0.006) and in the GI (p = 0.002). However, only IG showed significant improvements (p = 0.013) for Activities-Specific Balance Confident (ABC) in a comparison between before and after the 12-week research period. When comparing the differences verified with the intervention between CG and IG, only balance SPPB (p < 0.001) and sit-to-stand SPPB (p = 0.022) showed significant values.

Conclusion

He effectiveness of sensorimotor exercises provides balance gain in the elderly (p < 0.001) and positively impacts their confidence (p = 0.013) when performing their duties. It is concluded that the protocol presented in its different levels of difficulty is effective and important for the quality of life of the institutionalized sedentary elderly.

A Physically Active Lifestyle Can Protect against Age-Related Decline in Ankle Proprioception

This study examined whether physically active middle-aged (50-64 years) and older adults (65-80 years) demonstrate age-related ankle proprioceptive decline relative to younger counterparts. Empirical data indicate that ankle proprioception declines with aging and such sensory decline negatively affects balance. Using a passive motion apparatus, we employed a psychophysical forced-choice paradigm in which the ankle was passively plantarflexed to a reference position (15° or 25°) and a comparison position that was always smaller than the reference. Subsequently, participants indicated which position was more plantarflexed. As outcome measures of ankle position sense acuity, a just-noticeable-difference (JND) threshold and the uncertainty area (UA) were derived from the psychometric stimulus-response difference function for each participant. The JND threshold is a measure of proprioceptive bias and UA constitutes a measure of precision. The main results are: First, at the 15° reference, most middle-aged (74%) and older adults (71%) had thresholds within the range of the young adults. The respective median JND threshold of young adults was statistically lower when compared to both older groups. Second, no differences between age groups were observed at the 25° reference. Third, no age-related differences were found for UA at either reference. These data indicate that physically active aging adults may be spared from age-related decline in ankle position sense and that age-related differences emerge for small ankle displacements. The findings underscore the importance of remaining active during aging.

The neurobiological effects of mind-body exercise: a systematic review and meta-analysis of neuroimaging studies

The neurobiological effects of mind-body exercise on brain activation, functional neural connections and structural changes in the brain remain elusive. This systematic review and coordinate-based meta-analysis investigated the changes in resting-state and task-based brain activation, as well as structural brain changes before and after mind-body exercise compared to waitlist or active controls based on published structural or functional magnetic resonance imaging randomized controlled trials or cross-sectional studies. Electronic database search and manual search in relevant publications yielded 34 empirical studies with low-to-moderate risk of bias (assessed by Cochrane risk-of-bias tool for randomized trials or Joanna Briggs Institute's critical appraisal checklist for analytical cross-sectional studies) that fulfilled the inclusion criteria, with 26 studies included in the narrative synthesis and 8 studies included in the meta-analysis. Coordinate-based meta-analysis showed that, while mind-body exercise enhanced the activation of the left anterior cingulate cortex within the default mode network (DMN), it induced more deactivation in the left supramarginal gyrus within the ventral attention network (uncorrected ps < 0.05). Meta-regression with duration of mind-body practice as a factor showed that, the activation of right inferior parietal gyrus within the DMN showed a positive association with increasing years of practice (voxel-corrected p < 0.005). Although mind-body exercise is shown to selectively modulate brain functional networks supporting attentional control and self-awareness, the overall certainty of evidence is limited by small number of studies. Further investigations are needed to understand the effects of both short-term and long-term mind-body exercise on structural changes in the brain.PROSPERO registration number: CRD42021248984.

Comparison of postural sway in individuals with and without dynamic knee valgus

BACKGROUND

Dynamic knee valgus (DKV) is a multi-planar faulty movement pattern that can cause faulty postural control. The primary objective of this study is to investigate the differences in postural sway (PS) between individuals aged 18-30 years old diagnosed with and without DKV.

METHODS

In this cross-sectional study, 62 students (39 males and 23 females) with and without DKV (age: 24.58 ± 2.63 years) were selected and assigned to two groups by conducting the single-leg squat test in the screening stage. The Biodex balance system was then employed to compare the two groups in PS. Mann-Whitney U test was conducted to compare the groups in PS (p ≤ 0.05).

RESULTS

The study's findings indicate that individuals with DKV did not exhibit any significant differences, compared to those without, about the anterior-posterior stability index (with p values for both static and dynamic situations at 0.309 and 0.198, respectively), medial-lateral stability index (with p values for both static and dynamic situations at 0.883 and 0.500, respectively), and overall stability index (with p values for both static and dynamic situations at 0.277 and 0.086, respectively).

CONCLUSION

Though several possible factors could contribute to the lack of significant differences in postural sway between individuals with and without DKV, such as measurement tool differences, variable sensitivity in postural stability tests, and differences in movement variability and test stance, we recommend analyzing postural sway in more functional tasks and with different methodological patterns in future studies. Such research could help develop targeted interventions for individuals with DKV and offer a better understanding of the relationship between postural control and DKV.

Elbow Joint Position and Force Senses in Young and Adult Untrained People and Gymnasts

Joint position (JPS) and force senses (FS) are the proprioception modalities. While the development of JPS was investigated both in children/adult and athlete/untrained conditions, there is a lack of insight into the development of FS. Overall, 28 gymnasts and 25 untrained controls underwent proprioception testing. They were divided into two groups: 9 to 11-year-old boys (13 gymnasts and 10 non-athletes) and 18 to 25-year-old adults (15 gymnasts and 15 non-athletes). The testing was performed at an isokinetic dynamometer and included elbow JPS and FS (20% and 50% maximal voluntary contraction) tasks. Children had two times higher error in JPS (p < 0.01) and 50% higher errors in FS of both flexor (p < 0.001) and extensor muscles (p < 0.05) in comparison with adults. Only in the 50% maximal voluntary contraction task, gymnasts showed 33% lower error than the controls (p < 0.01). Untrained boys presented 54%, 132%, and 169% higher error for elbow flexor performance than young gymnasts, untrained adults, and adult gymnasts, respectively (p < 0.01). The 9 to 11-year-old participants were characterized by a lower precision of JPS and FS performance in comparison with adults. Gymnastic training can possibly accelerate the development of FS when higher loads are considered.

Range of Motion Remains Constant as Movement Rate Decreases During a Repetitive High-Speed Knee Flexion-Extension Task

Maintaining the range of motion in repetitive movement tasks is a crucial point since it directly influences the movement rate. Ensuring the movement amplitude can be reliably maintained when motor function is assessed by measuring the maximum movement rate is therefore a key consideration. However, the performed range of motion during such tasks is often not reported. This study aimed to determine whether individuals are able to maintain an intended range of motion during a knee flexion/extension maximum movement rate task in the absence of tactile and visual feedback. Twelve healthy male individuals performed knee flexion/extension at maximum speed for eight 10-s blocks in a 45° arc between 45° and 90°. The range of motion was monitored using a marker system and the movement rate was measured. The performed range of motion was not significantly different from the 45° arc during the task despite a 13.47% decrease in movement rate from the start to the end of the task. Nevertheless, there was only anecdotal evidence of no difference from 45° in most blocks, while on the second and seventh blocks, there was anecdotal evidence of differences in the Bayesian one-sample test. There was also no significant shift in the maximum flexion/extension angles throughout the task. Healthy male individuals were thus able to perform a consistent average predefined knee range of motion in a maximum movement rate task despite decreases in movement rate. This was achieved without constraint-inducing devices during the task, using only basic equipment and verbal feedback.

Cross-legged sitting posture effect on lumbar proprioception in young adults: a cross-sectional study

Background

The cross-legged sitting posture (CLS) is assumed by young adults’ results in a bent and unbalanced posture. The study purpose was to assess the effect of sitting in a cross-legged position (knee on knee) on lumbar proprioception. Thirty-six participants of both genders aged from 18 to 25 were selected and divided equally into group A who adapt to a cross-legged sitting posture and group B who adapt to erect sitting (not prefer cross-legged sitting). The Biodex System 3 pro isokinetic dynamometer was utilized to assess the lumbar proprioception by testing the lumbar region repositioning accuracy.

Results

The lumbar repositioning error of group A increased statistically significantly as compared to group B (p < 0.05).

Conclusions

Cross-legged sitting posture negatively affects lumbar proprioception compared with participants who adapt to erect sitting, and this effect should be considered in the avoidance of sitting in a cross-legged position and in prevention and intervention programs of lumbar proprioception impairment.

Reliability of joint position sense measured in the knee using the level function of the iPhone "Measure" application

An impaired joint position sense (JPS) causes activity limitations, postural imbalance, and falls. This study compares the reliability of knee JPS measurements between the iPhone's "Measure" application and VICON motion capture system. Eleven healthy participants were recruited for the study. To conduct the study measures, the blindfolded participant, with an iPhone fixed to the lower non-dominant leg, was seated with their lower limbs in a relaxed position. The examiner held the participant's leg at the target angle (30°/60° from initial position) for 5 s before releasing it. The participant was then instructed to move the leg to the same target angle and hold it for 5 s (replicated angle). Absolute angular error (AAE), i.e., the difference between the target and replicated angles, was measured. Intraclass and Pearson correlation coefficients established statistically significant relationships. The study comprised 6 males and 5 females of mean age 27.6±5.6 years, mean height 1.67±0.10 m, and mean body weight 60.7±10.3 kg. Strong correlations existed between iPhone and VICON 30° (ICC = 0.969, r = 0.960, P < 0.001) and 60° AAEs (ICC 0.969, r = 0.960, P < 0.001). Bland-Altman plots showed a mean difference of 0.43° and 0.20° between the AAE measurements at 30° and 60°, respectively. The iPhone's "Measure" application is a simple and reliable method for measuring JPS in clinical practice and sports/fitness settings.

The influence of sports practice, dominance and gender on the knee joint position sense

BACKGROUND

Physical activity, muscle fatigue or age have been suggested as factors that positively or negatively influence the knee joint position sense (KJPS). However, conflicting results about the influence of sports practice, limb dominance and gender are found in the literature. This study aimed to assess the influence of sports practice, limb dominance and gender on the KJPS of soccer players and untrained individuals.

METHODOLOGY

Sixty subjects participated in this study: 29 soccer players (SPs) and 31 untrained participants (UPs). KJPS was tested in a seated position, for the target angles of 20° and 45° of knee flexion, through an open kinetic chain technique and active repositioning method. Intergroup analysis was performed to compare KJPS between SPs and UPs and between gender, and intragroup analysis was performed to compare proprioceptive acuity between dominant and non-dominant limbs.

RESULTS

Knee repositioning errors were lower in SPs than in the UPs. Repositioning errors of the dominant and non-dominant limb were not significantly different in SPs (P > 0.05), but in UPs the dominant limb showed significantly lower repositioning errors, both for 20° (P = 0.046) and 45° target (P = 0.036). There were no gender differences in the KJPS in both groups (P > 0.05).

CONCLUSIONS

Proprioceptive acuity is higher in trained than in untrained participants. Dominance seems not to influence KJPS of SPs, but in UPs the dominant limb showed a higher accuracy. There were no differences in KJPS related to gender. These results suggest that sports practice, but neither gender nor limb dominance, may positively influence proprioceptive acuity.

Effects of two exercise programmes on joint position sense, dynamic balance and countermovement jump in male amateur football players. A randomised controlled trial

Introduction: The injury prevention and warm-up exercises programmes improve physical performance and injury ratio, but it is poorly investigated in amateur football. Objectives: To assess the effects of two warm-up multi-station programmes (IAI-Programme and FIFA11+) through JPS, LSDT and CMJ. Study design: Randomised controlled trial. Methods: 36 football players were randomised into 2 groups: IAI-Programme (n = 18) and FIFA11+ (n = 18) and performed the intervention protocol for 6 weeks. JPS, LSDT and CMJ were measured at baseline, after 6, 10 and 18 weeks (from baseline). The inter-group and intra-group differences were assessed by repeated-measures analysis of variance test (ANOVA). Results: Significant differences between groups were found after 18 weeks in the absolute angular error (-2.18[-4.33,-0.047], d = 0.69, p < 0.05) of the JPS and in the CMJ (p = 0.001, ŋ²p=,0.298) in favour of IAI-Programme when compared to FIFA11 +. No significant differences between groups were found in the LSDT. There were also intra-group differences observed in the LSDT in both groups. Conclusions: IAI-Programme can provide sensitive benefits with respect to the proprioceptive ability of knee flexion and CMJ than FIFA11 +. Both IAI-Programme and FIFA11+ present improvements in the dynamic postural control measured by the LSDT.

Comparison of the effects between low- versus medium-energy radial extracorporeal shock wave therapy on knee osteoarthritis: A randomised controlled trial

Objective

This study aimed to compare the effects between low- versus medium-energy radial extracorporeal shock wave therapy on knee osteoarthritis (KOA).

Method

Forty-five patients (26 women and 19 men) aged 45–55 years with grade 2 KOA were randomly assigned into the following three groups (all n = 15): Group A received low-energy radial shock wave therapy (2000 shock/session [10 Hz], energy flux density [EFD] 0.02 mJ/mm²) with strengthening exercises once per week for 4 weeks; Group B received medium-energy radial shock wave therapy (2000 shock/session [10 Hz], EFD 0.178 mJ/mm²) with strengthening exercises once per week for 4 weeks; and Group C (control group) received sham shock wave therapy with strengthening exercises once per week for 4 weeks. Severity of pain was determined using the visual analogue scale, and knee physical function was assessed using the Arabic version of the knee injury and osteoarthritis outcome score physical function short form. Knee proprioception was measured before and after the treatment programme using an isokinetic dynamometer.

Results

The within-group analysis showed significant differences in severity of pain, knee physical function, and knee proprioception in Groups A and B before and after the treatment programme (p < 0.05). The between-group analysis showed significant differences in all variables after treatment, with more significant differences observed in Group B than in Groups A and C (p < 0.05).

Conclusion

Low- and medium-energy radial shock wave therapies are effective modalities for the treatment of KOA, with medium-energy radial shock wave therapy being superior to low-energy radial shock wave therapy.

Age has no effect on ankle proprioception when movement history is controlled

It is generally accepted that proprioceptive ability deteriorates with age, although not all data support this view. We tested proprioception using three reliable tests at the ankle in 80 adults (19–80 yr). For all tests, the effects of muscle thixotropy were controlled. Under these conditions, we found no difference in proprioceptive acuity between young and old people.

Correlation of force sense error test measured by a pressure biofeedback unit and EMG activity of quadriceps femoris in healthy individuals

BACKGROUND

Our study developed a force sense error test (FSET) method for use on the quadriceps muscle, which could be employed in clinical practice to correlate the results of quadriceps muscle activity levels determined by surface electromyography (sEMG).

METHODS

Twenty-four healthy individuals were included in the study. A pressure biofeedback unit (PBU) placed under the knee joint, was used for force sense error test (FSET) evaluation. First, a maximum contraction value was determined with the PBU. Next, 50% and 65% of the maximum contraction value were used for the analysis. Concurrently, norm values for the quadriceps muscle activity levels were determined by sEMG. Simultaneously, quadriceps muscle activity levels were recorded while testing the FSET using the PBU. Each measurement was repeated in triplicate, and the average constant errors observed by the PBU were recorded in mmHg.

RESULTS

The FSET for both 50% and 65% of the normal mmHg value determined using the PBU positively correlated with activity change levels in the quadriceps muscle determined by sEMG (p < 0.05).

CONCLUSIONS

The relationship between the FSET measured using PBU and changes in the level of activity in the quadriceps muscle showed that a PBU can be used in clinical practice for proprioceptive evaluation of the knee region.

The long-term effect of complex regional pain syndrome type 1 on disability and quality of life after foot injury

PURPOSE

To study the long-term evolution of patients with lower-limb Complex Regional Pain Syndrome (CRPS), focusing on functional and proprioceptive aspects and quality of life.

METHODS

In 20 patients suffering from chronic distal lower-limb CRPS diagnosed using Budapest criteria, we assessed joint position sense and strength of the knee muscles at the CRPS and unaffected leg, functional exercise capacity, pain, CRPS severity score, quality of life and kinesiophobia. Similar assessments were performed in 20 age-matched controls.

RESULTS

The joint position performance (at 45°) was significantly lower for the CRPS leg as compared to controls. The knee extensor strength of the CRPS leg was significantly reduced as compared to the unaffected leg (-27%) and controls (-42%). CRPS patients showed significantly reduced performance at the 6 min-walk test as compared to their age group predicted value and controls. Patients suffering from CRPS for 3.8 years in average still exhibit high pain, severity and kinesiophobia scores.

CONCLUSIONS

Long-term deficits in strength and proprioceptive impairments are observed at the knee joint of the CRPS leg. This persistent functional disability has significant repercussions on the quality of life. We highlight the importance of including strength and proprioceptive exercises in the therapeutic approaches for CPRS patients.IMPLICATIONS FOR REHABILITATIONThe long-term evolution of patients suffering from lower-limb Complex Regional Pain Syndrome is associated with persistent disability, pain and impacts the quality of life.Strength, proprioceptive, functional and subjective assessments are necessary to better identify deficits.Rehabilitation should focus on the overall deficit of the affected and contralateral limb.

Age-related changes in leg proprioception: implications for postural control

In addition to being a prerequisite for many activities of daily living, the ability to maintain steady upright standing is a relevant model to study sensorimotor integrative function. Upright standing requires managing multimodal sensory inputs to produce finely tuned motor output that can be adjusted to accommodate changes in standing conditions and environment. The sensory information used for postural control mainly arises from the vestibular system of the inner ear, vision, and proprioception. Proprioception (sense of body position and movement) encompasses signals from mechanoreceptors (proprioceptors) located in muscles, tendons, and joint capsules. There is general agreement that proprioception signals from leg muscles provide the primary source of information for postural control. This is because of their exquisite sensitivity to detect body sway during unperturbed upright standing that mainly results from variations in leg muscle length induced by rotations around the ankle joint. However, aging is associated with alterations of muscle spindles and their neural pathways, which induce a decrease in the sensitivity, acuity, and integration of the proprioceptive signal. These alterations promote changes in postural control that reduce its efficiency and thereby may have deleterious consequences for the functional independence of an individual. This narrative review provides an overview of how aging alters the proprioceptive signal from the legs and presents compelling evidence that these changes modify the neural control of upright standing.

Effects of Tai Chi on partial anterior cruciate ligament injury: A single-blind, randomized-controlled trial

Objectives

This study aims to investigate the effects of Tai Chi (TC) exercises on muscle strength, pain, proprioception, and knee function in patients with partial anterior cruciate ligament (ACL) injuries.

Patients and methods

Between March 2017 and January 2018, a total of 58 patients with partial ACL injuries (30 male, 28 female; mean age 25.5±6.4; range, 18 to 36 years) were included in the study. The patients were randomly divided into two groups: TC group (n=29) and control group (n=29). For both groups, an activity modification approach was applied. The TC group participated in a 24-week TC exercise program, while no exercise or home-based program was administered to the control group. Isokinetic knee extension and flexion muscle strengths were evaluated at angular velocities of 60°/sec and 180°/sec. The visual analog scale (VAS), isokinetic system, Lysholm Knee Scale (LKS), and International Knee Documentation Committee 2000 (IKDC-2000) were used for the evaluation of pain, proprioception, and knee function, respectively.

Results

Significant changes were found in the TC group for the knee extensor muscle strength measured at an angular velocity of 60°/sec (p=0.012) and 180°/sec (p=0.011), VAS pain (p=0.005), and proprioception (measured with isokinetic device) (p<0.001). While knee extensor muscle strength, pain, proprioception, LKS, and IKDC-2000 scores improved in the TC group, improvements were recorded only for LKS and IKDC-2000 scores in the control group.

Conclusion

Based on these results, we conclude that TC exercises can yield positive outcomes on the knee extensor muscle strength, pain, proprioception and knee function in patients with partial ACL injuries. Hence, TC exercises can be used as a novel method by researchers and clinicians in the treatment of partial ACL injuries.

Superior Effects of High-Intensity Interval vs. Moderate-Intensity Continuous Training on Endothelial Function and Cardiorespiratory Fitness in Patients With Type 1 Diabetes: A Randomized Controlled Trial

This study aimed to compare the effect of high-intensity interval training (HIIT) with moderate-intensity continuous training (MCT) on endothelial function, oxidative stress and clinical fitness in patients with type 1 diabetes. Thirty-six type 1 diabetic patients (mean age 23.5 ± 6 years) were randomized into 3 groups: HIIT, MCT, and a non-exercising group (CON). Exercise was performed in a stationary cycle ergometers during 40 min, 3 times/week, for 8 weeks at 50–85% maximal heart rate (HR_max) in HIIT and 50% HR_max in MCT. Endothelial function was measured by flow-mediated dilation (FMD) [endothelium-dependent vasodilation (EDVD)], and smooth-muscle function by nitroglycerin-mediated dilation [endothelium-independent vasodilation (EIVD)]. Peak oxygen consumption (VO_2peak) and oxidative stress markers were determined before and after training. Endothelial dysfunction was defined as an increase < 8% in vascular diameter after cuff release. The trial is registered at ClinicalTrials.gov, identifier: NCT03451201. Twenty-seven patients completed the 8-week protocol, 9 in each group (3 random dropouts per group). Mean baseline EDVD was similar in all groups. After training, mean absolute EDVD response improved from baseline in HIIT: + 5.5 ± 5.4%, (P = 0.0059), but remained unchanged in MCT: 0.2 ± 4.1% (P = 0.8593) and in CON: −2.6 ± 6.4% (P = 0.2635). EDVD increase was greater in HIIT vs. MCT (P = 0.0074) and CON (P = 0.0042) (ANOVA with Bonferroni). Baseline VO_2peak was similar in all groups (P = 0.96). VO_2peak increased 17.6% from baseline after HIIT (P = 0.0001), but only 3% after MCT (P = 0.055); no change was detected in CON (P = 0.63). EIVD was unchanged in all groups (P = 0.18). Glycemic control was similar in all groups. In patients with type 1 diabetes without microvascular complications, 8-week HIIT produced greater improvement in endothelial function and physical fitness than MCT at a similar glycemic control.

O efeito da idade, da dupla tarefa e da visão no senso de posicionamento do tornozelo

RESUMO O objetivo desta pesquisa foi mensurar de forma objetiva a propriocepção, em diferentes situações (com e sem o auxílio da visão, com e sem tarefa cognitiva concomitante e de forma ativa ou passiva), em indivíduos idosos e adultos. Participaram do estudo dez adultos saudáveis e dez idosos saudáveis. Foram estudados os efeitos de diferentes restrições no desempenho do movimento por meio dos erros absoluto (precisão) e relativo (consistência). A mensuração do senso de posicionamento do tornozelo foi realizada com o dinamômetro isocinético Biodex Sistem 3. A análise de variância de quatro fatores e o teste post hoc de Tukey foram utilizados para analisar os parâmetros. Os resultados mostraram que o fator sujeito interfere no erro absoluto, pois os grupos apresentaram diferença significativa: os idosos erram mais quando comparados com os adultos. Os demais fatores (visão, tarefa cognitiva e tipo de movimento) não apresentaram diferença significativa. No erro relativo os resultados mostraram que a tarefa cognitiva concomitante ao movimento foi capaz de produzir diferença significante; entretanto os demais fatores (indivíduos, visão e tipo de movimentação) não foram capazes de produzir uma diferença significativa. A idade afeta a precisão do sentido proprioceptivo, independentemente da situação. Não houve diferença entre a realização do movimento com e sem o auxílio da visão, e a dupla tarefa (motora associada à cognitiva) afeta a consistência do movimento.

Does gender make a difference in knee rotation proprioception and range of motion in healthy subjects?

BACKGROUND

Knee proprioception is an integral component of neuromuscular control system that stabilizes the joints, reducing incidence of injury. Knee injuries' incidences differ between genders. Knee rotation is a component of different knee injury mechanisms. Gender differences in knee proprioception in internal (IR) and external (ER) rotations are not sufficiently studied.

OBJECTIVE

To check whether proprioceptive acuity in IR and ER directions of knee rotation is inherently lower in women compared to men. Moreover, to assess gender difference in ranges of knee rotation.

METHODS

Thirty volunteers (15 women and 15 men) participated. Knee proprioception acuity and ranges of knee rotation were assessed using the knee rotatory kinesthetic device (KRKD). Proprioception was tested using absolute judgment task, subject's ability to discriminate different rotation movements (stimuli) randomly presented, then just notable difference (JND) was calculated; least difference accurately discriminated in 75% of trials.

RESULTS

Women had lower proprioception acuity in IR than men (1.70∘± 0.79∘ and 1.12∘± 0.32∘, p= 0.011) respectively. Active IR (women: 41.29∘± 7.46∘, men 32.80∘± 3.64∘, p= 0.000), and passive IR (women: 53.43∘±11.67∘, men: 37.94∘± 5.22∘, p= 0.000) were higher in women compared to men. Active ER (women: 49.71∘± 11.37∘, men: 39.16∘± 5.46∘, p= 0.003), and passive ER (women: 62.29∘± 13.74∘, men: 48.89∘± 7.09∘, p= 0.002) were, also, higher in women.

CONCLUSION

Gender difference in knee proprioception acuity was found in IR, which is the direction of rotation that anterior cruciate ligament (ACL) stabilize. Women's ranges of knee rotation are greater than men in both IR and ER.

Knee position sense: does the time interval at the target angle affect position accuracy?

[Purpose] This study examined whether the interval at the target angle during knee joint position sense (JPS) affected reposition accuracy, and evaluated the consequence of this factor on test-retest reliability. [Subjects and Methods] Twenty healthy subjects participated in this study. Reposition ability was measured after the knee was placed at a target angle (ranging from 40° to 60°) for intervals of 3, 6, 9, and 12 seconds, in randomized order. Two trials were performed for each condition. The measurement was repeated after a week. The absolute error (AE) of each trial and average AE under each condition within the two measures were used for data analysis. [Results] No significant difference was found in comparing the AE or the average AE during all trials and between the two measures. Fair-to-good reliability was found for the AE results of all trials under the conditions of 3, 6, and 12 seconds. Poor reliability was found with time interval of 9 seconds. [Conclusion] The length of time needed to memorize the target angle during knee JPS test might affect test reliability. Practitioners can use this information when collecting JPS data.

The effect of kinesiology tape on knee proprioception in healthy subjects

BACKGROUND

Kinesiology tape can improve athletic performance; however, due to cutaneous stimulation its application can have an influence on proprioception.

OBJECTIVES

To determine the effects of kinesiology tape on knee proprioception applied to quadriceps, namely in the joint position sense (JPS) and in the threshold to detect passive movement (TTDPM), both immediately after and 24 h after its application.

METHODS

Thirty young healthy participants were randomly divided into experimental and control group. In the experimental group, a kinesiology tape on the quadriceps muscle was applied. The JPS and the TTDPM of the knee was assessed before, immediately after and 24 h after the kinesiology tape intervention.

RESULTS

No significant differences were found in the assessment made before intervention. The Friedman Test showed that kinesiology tape had no influence on JPS in either group over time (p > 0.05). However, the TTDPM decreased significantly immediately after and 24 h after its application (p < 0.05).

The effects of knee direction, physical activity and age on knee joint position sense

BACKGROUND

Previous research has suggested a decline in knee proprioception with age. Furthermore, regular participation in physical activity may improve proprioceptive ability. However, there is no large scale data on uninjured populations to confirm these theories. The aim of this study was to provide normative knee joint position data (JPS) from healthy participants aged 18-82years to evaluate the effects of age, physical activity and knee direction.

METHODS

A sample of 116 participants across five age groups was used. The main outcome measures were knee JPS absolute error scores into flexion and extension, Tegner activity levels and General Practitioner Physical Activity Questionnaire results.

RESULTS

Absolute error scores in to knee flexion were 3.6°, 3.9°, 3.5°, 3.7° and 3.1° and knee extension were 2.7°, 2.5°, 2.9°, 3.4° and 3.9° for ages 15-29, 30-44, 45-59, 60-74 and 75 years old respectively. Knee extension and flexion absolute error scores were significantly different when age group data were pooled. There was a significant effect of age and activity level on joint position sense into knee extension. Age and lower Tegner scores were also negatively correlated to joint position sense into knee extension.

CONCLUSIONS

The results provide some evidence for a decline in knee joint position sense with age. Further, active populations may have heightened static proprioception compared to inactive groups. Normative knee joint position sense data is provided and may be used by practitioners to identify patients with reduced proprioceptive ability.

Correlation study of knee joint proprioception test results using common test methods

[Purpose] To study the correlation of the results obtained from different proprioception test methods, namely, the joint angle reset method, the motion minimum threshold measurement method, and the force sense reproduction method, performed on the same subjects' knees. [Subjects and Methods] Different proprioception test methods, the joint angle reset method, the motion minimum threshold measurement method and the force sense reproduction method were used to test the knees of 30 healthy young men. [Results] Correlations were found in the following descending order from strong to weak: the correlation between the joint angle reset method and the force sense reproduction method (correlation coefficient of 0.41), the correlation between the joint angle reset method and the motion minimum threshold measurement method (correlation coefficient of 0.29), the correlation between the motion minimum threshold measurement method and the force sense reproduce method (correlation coefficient of 0.15). [Conclusion] No correlation was found among the results obtained using the joint angle reset method, the motion minimum threshold measurement method and the force sense reproduction method. Therefore, no correlation was found among the position sense, the motion sense and the force sense represented by these methods. Using the results of only one of the test methods to represent proprioception is one-sided. Force sensation depends more on the sensory input of information from the Golgi tendon organs, motion sense depends more on the input information of the muscle spindles, and position sense relies on the double input information of the muscle spindles and the Golgi tendon organs.

Comparison of the effect of weight-bearing and non-weight-bearing positions on knee position sense in patients with chronic stroke

[Purpose] The purpose of this study was to investigate the knee joint proprioception in weight-bearing (WB) and non-weight-bearing (NWB) positions and to study the difference between the methods in chronic stroke patients. [Subjects and Methods] The subjects were 15 stroke patients who were randomly scheduled to perform both positions by a physical therapist not involved in the study. The subjects performed the positions (WB and NWB) based on a randomized controlled cross-sectional design. WB subjects were positioned in one-leg standing to assess the knee joint position sense. NWB subjects were instructed to sit comfortably in a chair and maintain the knees at 90° of flexion with the leg out of the plinth. [Results] The results revealed that the WB position showed a significant difference in knee position sense. The proprioception sense in the WB position was a higher than that in the NWB position. [Conclusion] The knee proprioception of chronic stroke patients differs between the weight-bearing and non-weight-bearing positions.

Comparisons of changes in the two-point discrimination test following muscle fatigue in healthy adults

[Purpose] This study aimed to examine the effects of muscle fatigue on skin sensation by looking at changes in two-point discrimination (2PD) after inducing muscle fatigue. [Subjects] Thirty-four young and healthy adults with no pathological symptoms (17 males; 17 females) participated in this study. [Methods] Continuous isometric contraction was applied to the upper and lower extremities with an intensity of 50% of the maximal muscle strength to trigger muscle fatigue, and then the 2PD test was conducted on the 3 cm medial area of the elbow and 5 cm area of the knee bone. [Results] After muscle fatigue was induced, the 2PD distance significantly increased in the upper and lower extremities of both males and females. Before triggering muscle fatigue, the 2PD distance was longer in males than females, but after causing muscle fatigue, there was no difference between males and females. The increase in 2PD distance after the experiment was more significant in females than males. [Conclusion] Muscle fatigue has an effect of reducing the skin’s sensory faculty by increasing the 2PD distance in the skin. There is a difference in the response of the skin according to body area and gender; therefore, caution is needed to avoid triggering fatigue during exercise.

Postural sway in single-limb and bilateral quiet standing after unilateral total knee arthroplasty

AIM

To investigate whether total knee arthroplasty (TKA) was associated with stability in single-limb stance and whether reduced stability in single-limb stance was associated with increased postural sway in bilateral quiet standing.

METHODS

3D kinematics for center of mass was used to assess postural sway in 23 subjects with TKA and 23 controls. Tests included bilateral quiet standing with and without vision and on a compliant surface, and single-limb stance.

RESULTS

30% of the subjects in the TKA group were unable to maintain single-limb stance for 20s on any leg. Of the 70% in the TKA group able to stand on one leg, mean sway velocity in the medio-lateral direction was marginally higher for the prosthetic side (p=.02), but no differences were found between the TKA and the control group in single-limb stance. Performance in bilateral quiet standing was similar in TKA-subjects, able as well as unable to stand on one leg, and controls. Reduced quadriceps strength in the contralateral leg, higher BMI, and older age predicted failure to maintain single-limb stance.

CONCLUSION

In subjects able to stand on one leg, performance was considered comparable between the prosthetic and contralateral side and between groups. Inability to stand on one leg did not affect postural sway in bilateral quiet standing. The results suggest that inability to maintain single-limb stance is explained by reduced physical capacity rather than the knee condition in itself. The present study emphasizes the importance of physical activity to improve strength and functional capacity.

Home based exercise to improve turning and mobility performance among community dwelling older adults: protocol for a randomized controlled trial

BACKGROUND

Turning is a common activity for older people, and is one of the activities commonly associated with falls during walking. Falls that occur while walking and turning have also been associated with an increased risk of hip fracture in older people. Despite the importance of stability during turning, there has been little focus on identifying this impairment in at risk older people, or in evaluating interventions aiming to improve this outcome. This study will evaluate the effectiveness of a 16 week tailored home based exercise program in older adults aged (50 years and above) who were identified as having unsteadiness during turning.

METHODS/DESIGN

A single blind randomized controlled trial will be conducted, with assessors blind to group allocation. Study participants will be aged 50 years and above, living in the community and have been identified as having impaired turning ability [outside of age and gender normal limits on the Step Quick Turn (180 degree turn) task on the Neurocom® Balance Master with long plate]. After a comprehensive baseline assessment, those classified as having balance impairment while turning will be randomized to intervention or control group. The intervention group will receive a 16 week individualized balance and strength home exercise program, based on the Otago Exercise Program with additional exercises focused on improving turning ability. Intervention group will attend four visit to the assessment centre over 16 weeks period, for provision, monitoring, modification of the exercise and encourage ongoing participation. Participants in the control group will continue with their usual activities. All participants will be re-assessed on completion of the 16 week program. Primary outcome measures will be the Step Quick Turn Test and Timed-Up and Go test. Secondary outcomes will include other clinical measures of balance, psychological aspects of falls, incidence of falls and falls risk factors.

DISCUSSION

Results of this study will provide useful information for clinicians on the types of exercises to improve turning ability in older people with increased falls risk and the effectiveness of these exercises in improving outcomes.

TRIAL REGISTRATION

ACTRN12613000855729.

Accuracy and precision of a custom camera-based system for 2-d and 3-d motion tracking during speech and nonspeech motor tasks

PURPOSE Studying normal or disordered motor control requires accurate motion tracking of the effectors (e.g., orofacial structures). The cost of electromagnetic, optoelectronic, and ultrasound systems is prohibitive for many laboratories and limits clinical applications. For external movements (lips, jaw), video-based systems may be a viable alternative, provided that they offer high temporal resolution and submillimeter accuracy. METHOD The authors examined the accuracy and precision of 2-D and 3-D data recorded with a system that combines consumer-grade digital cameras capturing 60, 120, or 240 frames per second (fps), retro-reflective markers, commercially available computer software (APAS, Ariel Dynamics), and a custom calibration device. RESULTS Overall root-mean-square error (RMSE) across tests was 0.15 mm for static tracking and 0.26 mm for dynamic tracking, with corresponding precision (SD) values of 0.11 and 0.19 mm, respectively. The effect of frame rate varied across conditions, but, generally, accuracy was reduced at 240 fps. The effect of marker size (3- vs. 6-mm diameter) was negligible at all frame rates for both 2-D and 3-D data. CONCLUSION Motion tracking with consumer-grade digital cameras and the APAS software can achieve submillimeter accuracy at frame rates that are appropriate for kinematic analyses of lip/jaw movements for both research and clinical purposes.

A systematic review to determine the reliability of knee joint position sense assessment measures

BACKGROUND

The assessment of joint position sense (JPS) is the most widely used measurement of knee proprioceptive capability within the literature. However, it remains unclear what the most reliable method is to assess this. The purpose of this study was to determine the intra- and inter-rater reliability of the various methods used to assess knee JPS.

METHODS

A systematic review of published and unpublished literature sources was conducted up to June 2012. All studies principally assessing the reliability (intra- or inter-rater) or reproducibility of a JPS of the knee were included. The methodological quality of each study was reviewed using the Critical Appraisal Skills Programme tool.

RESULTS

A total of 18 studies were eligible, assessing the reliability of JPS with 456 knees. The reliability of four methods of JPS has been recorded: position replication using a model, image recorded angulation, electrogoniometry and dynamometry/angular motion chair. Intra-rater reliability was good for the assessment of JPS using photographs and digital images, and replicating knee position using a paper model, this was good but variable when electrogoniometry was used, and moderate but variable when assessed using dynamometry/angle motion chairs. The assessment of JPS by image recorded angulation, electrogoniometry and dynamometry/angular motion chair has demonstrated good inter-rater reliability.

CONCLUSIONS

Whilst JPS methods appear to have variable reliability, the four assessment methods should be further assessed with pathological populations such as those following patellar dislocation or anterior cruciate ligament rupture. This will better facilitate the generalisability of JPS assessment methods to inform clinical practice.