Test-retest reliability of isokinetic dynamometry for the assessment of spasticity of the knee flexors and knee extensors in children with cerebral palsy

Use of Isokinetic Dynamometry To Assess Muscle Function In Burned Patients Is A Reliable Tool To Assist Progressive Resistance Exercise Prescription

Isokinetic dynamometry is used during exercise testing and rehabilitation to obtain a quantitative strength measurement on which progressive strength training programs can be based. This study assesses the test-retest reliability of isokinetic leg function in the knee flexors and extensors at 150°/s in children and young adults with severe burns to be used for rehabilitation exercise program prescription. In 39 severely burned patients (49 ± 14% total body surface area burn [TBSA], mean ± SD; 34 ± 21% TBSA 3rd degree; 14 ± 5 years, 153.3 ± 16.5 cm height; 53.8 ± 17.9 kg) knee flexion/extension isokinetic dynamometry at 150°/s was performed on each patient's dominant leg in two sessions. The patient was acquainted with the test and performed 1 set of 10 repetitions at 150°/s. A second session of 1 set of 10 repetitions at 150°/ was performed within 24 h of the first. Muscle function outcomes were knee flexion/extension peak torque, average peak torque, and average power. One-sample paired t tests were performed for all muscle function outcomes; intraclass correlation coefficients and r2 values with session two as a function of session one were calculated. Sessions did not differ significantly in knee extension or flexion for any muscle function outcome or the hamstrings to quadriceps ratio. All intraclass correlation coefficients were >0.89 and r2 > 0.79. Test-retest isokinetic dynamometry functional measurements in the knee flexors and extensors at 150°/s are reliable in the burn population and may aid resistance rehabilitation program prescriptions.

Combining intensive rehabilitation with a non-functional isokinetic strengthening program in adolescents with cerebral palsy: a study protocol for a randomized controlled trial

BACKGROUND

Cerebral palsy (CP) is the most common brain injury in the pediatric population. CP patients present different affectations such as decreased muscle strength, gait deviations, impaired proprioception, and spasticity. Isokinetic strengthening programs combined with an intensive rehabilitation may improve muscle strength and therefore gait efficiency. Clinical Trials: The protocol has been accepted by the French National Ethics Committee (IDRCB: 2022-A00431-42).

OBJECTIVE

The primary aim of this randomized controlled trial is to compare the effect of an intensive rehabilitation combined with a non-functional isokinetic progressive strengthening program to an intensive rehabilitation alone on gait parameters and muscle strength in CP patients. Another goal of the current study is to determine whether adding an isokinetic program to an intensive rehabilitation is more effective than an intensive reha-bilitation alone on decreasing spasticity and improving joint position sense in CP patients.

METHODS

Thirty adolescents with spastic diplegia CP (GMFCS level I to III) will be randomized, by an independent researcher, into a 3-week intensive rehabilitation and isokinetic pro-gressive strengthening group or an intensive rehabilitation control group. Gait param-eters, muscle strength, spasticity and knee joint position sense will be assessed. These variables will be evaluated at baseline (T0) and at the end of the intervention (T1). The intensive rehabilitation will consist of physiotherapy sessions twice a day and hydro-therapy and virtual reality gait training once a day. The isokinetic training group will have a total of 9 supervised isokinetic strength training focusing on knee flexors and extensors with different execution speeds.

RESULTS

The protocol has been accepted by the French National Ethics Committee in October 2022. Inclusion of patients will start in November 2022.

CONCLUSIONS

The combination of an intensive rehabilitation with an isokinetic program on knee flexors and extensors have not been studied yet. The findings of this study may determine if an isokinetic strength training program of knee flexors and extensors is benefic to improve gait parameters, muscle strength, spasticity, and joint position sense in adolescents with spastic diplegia.

CLINICALTRIAL

The protocol has been accepted by the French National Ethics Committee (IDRCB: 2022-A00431-42).

Effects of Home-Based Electrical Stimulation on Plasma Cytokines Profile, Redox Biomarkers, and Metalloproteinases in the Heart Failure with Reduced Ejection Fraction: A Randomized Trial

Background: Low-frequency electrical stimulation (LFES) is an adjuvant method for heart failure (HF) patients with restrictions to start an exercise. However, the impact on molecular changes in circulating is unknown. We investigated the effects of 10 weeks of home-based LFES on plasma cytokines profile, redox biomarkers, metalloproteinases (MMPs) activity, and exercise performance in HF patients. Methods: Twenty-four HF patients (52.45 ± 9.15 years) with reduced ejection fraction (HFrEF) (EF < 40%), were randomly assigned to a home-based LFES or sham protocol. Plasma cytokines profile was assessed through interleukins, interferon-gamma, and tumor necrosis factor levels. Oxidative stress was evaluated through ferric reducing antioxidant power, thiobarbituric acid-reactive substances, and inducible nitric oxide synthase. The MMPs activity were analyzed by zymography. Cardiorespiratory capacity and muscle strength were evaluated by cardiopulmonary test and isokinetic. Results: LFES was able to increase the active-MMP2 activity post compared to pre-training (0.057 to 0.163, p = 0.0001), while it decreased the active-MMP9 (0.135 to 0.093, p = 0.02). However, it did not elicit changes in cytokines, redox biomarkers, or exercise performance (p > 0.05). Conclusion: LFES protocol is a promising intervention to modulate MMPs activity in HFrEF patients, although with limited functional effects. These preliminary responses may help the muscle to adapt to future mechanical demands dynamically.

Technology-assisted assessment of spasticity: a systematic review

BACKGROUND

Spasticity is defined as "a motor disorder characterised by a velocity dependent increase in tonic stretch reflexes (muscle tone) with exaggerated tendon jerks". It is a highly prevalent condition following stroke and other neurological conditions. Clinical assessment of spasticity relies predominantly on manual, non-instrumented, clinical scales. Technology based solutions have been developed in the last decades to offer more specific, sensitive and accurate alternatives but no consensus exists on these different approaches.

METHOD

A systematic review of literature of technology-based methods aiming at the assessment of spasticity was performed. The approaches taken in the studies were classified based on the method used as well as their outcome measures. The psychometric properties and usability of the methods and outcome measures reported were evaluated.

RESULTS

124 studies were included in the analysis. 78 different outcome measures were identified, among which seven were used in more than 10 different studies each. The different methods rely on a wide range of different equipment (from robotic systems to simple goniometers) affecting their cost and usability. Studies equivalently applied to the lower and upper limbs (48% and 52%, respectively). A majority of studies applied to a stroke population (N = 79). More than half the papers did not report thoroughly the psychometric properties of the measures. Analysis identified that only 54 studies used measures specific to spasticity. Repeatability and discriminant validity were found to be of good quality in respectively 25 and 42 studies but were most often not evaluated (N = 95 and N = 78). Clinical validity was commonly assessed only against clinical scales (N = 33). Sensitivity of the measure was assessed in only three studies.

CONCLUSION

The development of a large diversity of assessment approaches appears to be done at the expense of their careful evaluation. Still, among the well validated approaches, the ones based on manual stretching and measuring a muscle activity reaction and the ones leveraging controlled stretches while isolating the stretch-reflex torque component appear as the two promising practical alternatives to clinical scales. These methods should be further evaluated, including on their sensitivity, to fully inform on their potential.

Spasticity Measurement Tools and Their Psychometric Properties Among Children and Adolescents With Cerebral Palsy: A Systematic Review

PURPOSE

To identify and appraise the literature on the psychometric properties of spasticity measures that have been used among children and adolescents with cerebral palsy (CP).

METHODS

A comprehensive literature search was conducted in 5 databases. Two independent reviewers screened the literature search results for relevant studies. Reviewers extracted the data using a standardized form and study quality was assessed using a critical appraisal tool.

RESULTS

A total of 44 studies met the selection criteria and were included. We identified 22 different spasticity assessment tools, with different levels of evidence regarding their psychometric properties.

CONCLUSION

The findings of the current review indicate that there is limited evidence to recommend 1 spasticity assessment method for children and adolescents with CP. Spasticity assessment in its current state lacks a method that possesses the necessary psychometric properties and is easily used in the clinical setting.

Effect of extracorporeal shock wave therapy on spastic equinus foot in children with unilateral cerebral palsy

Objectives

This study aims to investigate the effects of radial extracorporeal shock wave therapy on selective motor control, spasticity, gross motor function, and balance in children with unilateral cerebral palsy.

Methods

This randomised controlled study recruited 34 children aged 7–9 with spastic unilateral cerebral palsy. They were randomly allocated to either the control or study group. Both groups undertook traditional exercises for 12 weeks. The study group received shock waves (one session/week) on the calf muscle (1500 shocks, frequency of 4 Hz, energy of 0.030 mJ/mm²). All children were evaluated at baseline and after 12 weeks using the Modified Ashworth Scale, a Biodex System 4 isokinetic dynamometer, dimensions D (standing) and E (walking) of the Gross Motor Function Measure – 88, the Trost Selective Motor Control test, and the single leg standing test.

Results

Mixed analysis of variance and Mann–Whitney results showed significant improvement in eccentric peak torque, torque threshold angles, gross motor function, selective motor control, and balance in the study group compared with the control group (p < 0.05).

Conclusions

Shock wave therapy may be a valuable instrument for reducing spasticity, improving the ability to isolate and control movement, and consequently, improving balance and gross motor function in children with unilateral cerebral palsy.

Applying Stretch to Evoke Hyperreflexia in Spasticity Testing: Velocity vs. Acceleration

In neurological diseases, muscles often become hyper-resistant to stretch due to hyperreflexia, an exaggerated stretch reflex response that is considered to primarily depend on the muscle's stretch velocity. However, there is still limited understanding of how different biomechanical triggers applied during clinical tests evoke these reflex responses. We examined the effect of imposing a rotation with increasing velocity vs. increasing acceleration on triceps surae muscle repsonse in children with spastic paresis (SP) and compared the responses to those measured in typically developing (TD) children. A motor-operated ankle manipulator was used to apply different bell-shaped movement profiles, with three levels of maximum velocity (70, 110, and 150°/s) and three levels of maximum acceleration (500, 750, and 1,000°/s²). For each profile and both groups, we evaluated the amount of evoked triceps surae muscle activation. In SP, we evaluated two additional characteristics: the intensity of the response (peak EMG burst) and the time from movement initiation to onset of the EMG burst. As expected, the amount of evoked muscle activation was larger in SP compared to TD (all muscles: p < 0.001) and only sensitive to biomechanical triggers in SP. Further investigation of the responses in SP showed that peak EMG bursts increased in profiles with higher peak velocity (lateral gastrocnemius: p = 0.04), which was emphasized by fair correlations with increased velocity at EMG burst onset (all muscles: r > 0.33-0.36, p ≤ 0.008), but showed no significant effect for acceleration. However, the EMG burst was evoked faster with higher peak acceleration (all muscles p < 0.001) whereas it was delayed in profiles with higher peak velocity (medial gastrocnemius and soleus: p < 0.006). We conclude that while exaggerated response intensity (peak EMG burst) seems linked to stretch velocity, higher accelerations seem to evoke faster responses (time to EMG burst onset) in triceps surae muscles in SP. Understanding and controlling for the distinct effects of different biological triggers, including velocity, acceleration but also length and force of the applied movement, will contribute to the development of more precise clinical measurement tools. This is especially important when aiming to understand the role of hyperreflexia during functional movements where the biomechanical inputs are multiple and changing.

ATLAS2030 Pediatric Gait Exoskeleton: Changes on Range of Motion, Strength and Spasticity in Children With Cerebral Palsy. A Case Series Study

Background: Cerebral Palsy (CP), the most common motor disability in childhood, affects individual's motor skills, movement and posture. This results in limited activity and a low social participation. The ATLAS2030 exoskeleton is a pediatric device that enables gait rehabilitation for children with neurological or neuromuscular pathologies with gait pathology. Purpose: To study changes in relation to range of motion (ROM), strength and spasticity in children with CP after using the ATLAS2030 gait exoskeleton. Methods and Participants: Three children (mean age 8.0 ± 2.0), two girls and one boy, two of them with GMFCS IV and one with GMFCS III, received robot-assisted gait training (RAGT) with ATLAS2030 for one month. Results: The average time of exoskeleton use was 54.7 ± 10.4 min in all sessions, and all participants were able to perform all exercises. The strength of all muscle groups was increased after the 10 sessions for the participants assessed and the limited ROM in the sagittal plane (hip and knee extension and ankle dorsiflexion) decreased after the use of the exoskeleton compared to the initial state. Spasticity was reduced at the end of the sessions after the use of the exoskeleton compared to their initial state. Conclusion: The ROM, spasticity and strength were improved after RAGT with ATLAS2030 exoskeleton in these children with CP. However, further studies with larger samples should be carried out to confirm our findings.

Increased Muscle Activity Accompanying With Decreased Complexity as Spasticity Appears: High-Density EMG-Based Case Studies on Stroke Patients

Spasticity is a major contributor to pain, disabilities and many secondary complications after stroke. Investigating the effect of spasticity on neuromuscular function in stroke patients may facilitate the development of its clinical treatment, while the underlying mechanism of spasticity still remains unclear. The aim of this study is to explore the difference in the neuromuscular response to passive stretch between healthy subjects and stroke patients with spasticity. Five healthy subjects and three stroke patients with spastic elbow flexor were recruited to complete the passive stretch at four angular velocities (10°/s, 60°/s, 120°/s, and 180°/s) performed by an isokinetic dynamometer. Meanwhile, the 64-channel electromyography (EMG) signals from biceps brachii muscle were recorded. The root mean square (RMS) and fuzzy entropy (FuzzyEn) of EMG recordings of each channel were calculated, and the relationship between the average value of RMS and FuzzyEn over 64-channel was examined. The two groups showed similar performance from results that RMS increased and FuzzyEn decreased with the increment of stretch velocity, and the RMS was negatively correlated with FuzzyEn. The difference is that stroke patients showed higher RMS and lower FuzzyEn during quick stretch than the healthy group. Furthermore, compared with the healthy group, distinct variations of spatial distribution within the spastic muscle were found in the EMG activity of stroke patients. These results suggested that a large number of motor units were recruited synchronously in the presence of spasticity, and this recruitment pattern was non-uniform in the whole muscle. Using a combination of RMS and FuzzyEn calculated from high-density EMG (HD-EMG) recordings can provide an innovative insight into the physiological mechanism underlying spasticity, and FuzzyEn could potentially be used as a new indicator for spasticity, which would be beneficial to clinical intervention and further research on spasticity.

Test-retest reliability and responsiveness of isokinetic dynamometry to assess wrist flexor muscle spasticity in subacute post-stroke hemiparesis

INTRODUCTION

To overcome the limitations of clinical scales, objective measurement methods are becoming prominent in spasticity assessment. The aim of this study was to assess the test-retest reliability and responsiveness of isokinetic dynamometry to evaluate wrist flexor spasticity in patients with subacute stroke.

METHODS

Twenty six patients with hemiparetic stroke (13 men, 13 women, mean age 51.38 ± 12.64 years) volunteered to take part in this study. Resistive torque in the wrist flexor muscles was measured twice, 1 day apart, with an isokinetic dynamometer. Wrist extension was tested at four speeds (5, 60, 120 and 180°/s). Torque response at the lowest speed (5°/s) was attributed to the non-neural component of the wrist flexor muscles, and was subtracted from the torque response at the higher speeds to calculate reflex torque (spasticity). The reliability of reflex torque measurements at 60, 120 and 180°/s was evaluated with the intraclass correlation coefficient (ICC_2,1) and standard error of measurement (SEM and SEM%), which reflect reproducibility and measurement error, respectively. Responsiveness was calculated as the smallest real difference (SRD and SRD%).

RESULTS

Reproducibility was excellent at different movement speeds (ICC_{2, 1} 0.76-0.85). SEM% ranged from 11% to 21%, and SRD% ranged from 30% to 58%. ICC values increased, and SEM% and SRD% decreased, as test speed increased.

CONCLUSION

Our results support the reliability and responsiveness of isokinetic dynamometry to quantify spasticity in wrist flexor muscles in patients with subacute stroke. Reliability and responsiveness increased as the speed of wrist movement increased.

Reliability of isokinetic knee strength measurements in children: A systematic review and meta-analysis

Measuring muscle strength using isokinetic dynamometry allows evaluating and comparing normal and sick children, establishing recovery and rehabilitation goals, and quantitatively monitoring the course of a disease and the response to treatment. The purpose of this study was to carry out a systematic review and meta-analysis focusing on studies that examined the test-retest reliability of isokinetic knee strength measurements in children. This study is important because isokinetic dynamometry is the gold standard for evaluating muscle strength and it allows comparing muscle performance in children. The databases used were PubMed, Web of Science Scopus, and Embase (up to July 26, 2019). Only studies published in English were included in this review. All studies focused on the reliability of isokinetic knees in healthy children or those with cerebral palsy applied to dynamic contractions (concentric or eccentric) and provided measures of strength, reproducibility, ICC, peak torque, or SEM. We found a total of 143 abstracts and examined 94 articles to determine if they met the inclusion criteria. Finally, 10 articles were included in the systematic review and five studies (96 subjects) formed the meta-analysis sample, all of which focused on the reliability of isokinetic knees in the concentric mode. The CAT and QAREL scales were used to assess the quality of the included studies. The meta-analysis revealed high intra-class correlation coefficients (ICC) (0.84; p < 0.001; n = 96 subjects) in the flexion and excellent intra-class correlation coefficients (ICC 0.90; p < 0.001; n = 96 subjects) in the extension. Isokinetic dynamometry could be indicated as a method for measuring muscle strength training in children. However, the reviewed studies suggest some methodological issues in isokinetic tests, such as the rest days between testing and retesting, using the same speeds, protocols, and evaluators, and the performance of the subjects, so more research is required.

Intra- and inter-tester reliability of spasticity assessment in standing position in children and adolescents with cerebral palsy using a paediatric exoskeleton

BACKGROUND

The L-STIFF tool of the Lokomat evaluates the hip and knee flexors and extensors spasticity in a standing position. It moves the lower limb at a controlled velocity, measuring joint resistance to passive movements. Since its reliability in children with cerebral palsy remains unknown, our goal was to evaluate the relative and absolute reliability of L-STIFF in children with cerebral palsy.

METHODS

Reliability was determined in 16 children with cerebral palsy by two experienced therapists. The changes in resistive torque in hip and knee in both flexion and extension were measured. Relative and absolute reliability were estimated using the intraclass correlation coefficient, standard error of measurement, and minimal detectable change. Reliability was assessed on three levels: (1) intra- and (2) inter-tester within session, and (3) intra-tester between sessions.

RESULTS

Intraclass correlation coefficients were moderate to excellent for intra-tester reliability (all p ≤ 0.01). The standard error of measurement ranged from 0.005 to 0.021 Nm/° (i.e., 7-16%) and minimal detectable change from 0.014 to 0.059 Nm/°. Inter-tester intraclass correlation coefficients ranged from 0.32 to 0.70 (all p ≤ 0.01), standard error of measurement ranged from 0.012 to 0.029 Nm/° (i.e., 6-39%), and minimal detectable change ranged from 0.033 to 0.082 Nm/°. L-STIFF reliability was better during fast and medium movement speeds compared to slow speeds.

CONCLUSIONS

The assessment tool L-STIFF is a promising tool for quantifying lower limb spasticity in children with cerebral palsy in a standing position. However, the results should be interpreted carefully.Implications for RehabilitationL-STIFF is a promising tool for evaluating lower limb spasticity in standing position.A special care must be given to the installation and alignment of the participant into the Lokomat to minimize erroneous spasticity measurement.Relative standard error of measurement and minimal detectable change should be used to analyze changes spasticity.

Biomechanical investigation of the modified Tardieu Scale in assessing knee extensor spasticity poststroke

OBJECTIVE

The modified Tardieu Scale (MTS) is a clinical tool for the measurement of muscle spasticity. The present study aimed to investigate the relationship between the MTS and the slope of the work-velocity curve as a biomechanical measure in assessing knee extensor muscle spasticity in patients with stroke.

METHODS

Thirty patients with stroke (22 female, 8 male; mean age 55.4 ± 12.0 years) participated in this study. The knee extensor spasticity was assessed with the MTS. An isokinetic dynamometer was used to move the knee passively from full extension to 90° flexion at speeds of 60°/s, 120°/s, 180°/s, and 240°/s to collect torque-angle data. The slope of the work-velocity curve was calculated using linear regression [J/(°/s)].

RESULTS

The mean of R2-R1 component of MTS was 19.73 (SD 29.85). The mean work significantly decreased as the speed increased (p < .001). The mean (SD) slope for the work-velocity curve was -0.83 (SD 0.73, range -2.6-0.3). There was no significant relationship between the R₂ -R₁ and the slope of work-velocity curve (r = 0.09, p = .62).

CONCLUSIONS

The lack of significant relationship between the MTS and the slope of work-velocity curve may question the usefulness of the MTS as a valid measure of muscle spasticity after stroke.

Effects of intermittent theta burst stimulation on spasticity after stroke

Spasticity is a common cause of long-term disability in poststroke hemiplegic patients. We investigated whether intermittent theta burst stimulation (iTBS) could reduce upper-limb spasticity after a stroke. Fifteen hemiplegic stroke patients were recruited for a double-blind sham-controlled cross-over design study. A single session of iTBS or sham stimulation was delivered on the motor hotspot of the affected flexor carpi radialis muscle in a random and counterbalanced order with a 1-week interval. Modified Ashworth scale (MAS), modified Tardieu scale (MTS), H-wave/M-wave amplitude ratio, peak torque (PT), peak torque angle (PTA), work of affected wrist flexor, and rectified integrated electromyographic activity of the flexor carpi radialis muscle were measured before, immediately after, 30 min after, and 1 week after iTBS or sham stimulation. Repeated-measures analysis of variance showed a significant interaction between time and intervention for the MAS, MTS, PT, PTA, and rectified integrated electromyographic activity (P<0.05), indicating that these parameters were significantly improved by iTBS compared with sham stimulation. However, the H-wave/M-wave amplitude ratio and work were not affected. MAS and MTS significantly improved for at least 30 min after iTBS, but the other parameters only improved immediately after iTBS (P<0.05). In conclusion, iTBS on the affected hemisphere may help to reduce poststroke spasticity transiently.

Dynamometer-based measure of spasticity confirms limited association between plantarflexor spasticity and walking function in persons with multiple sclerosis

The literature shows inconsistent evidence regarding the association between clinically assessed plantar-flexor (PF) spasticity and walking function in ambulatory persons with multiple sclerosis (pwMS). The use of a dynamometer-based spasticity measure (DSM) may help to clarify this association. Our cohort included 42 pwMS (27 female, 15 male; age: 42.9 +/- 10.1 yr) with mild clinical disability (Expanded Disability Status Scale score: 3.6 +/- 1.6). PF spasticity was assessed using a clinical measure, the modified Ashworth Scale (MAS), and an instrumented measure, the DSM. Walking function was assessed by the timed 25-foot walk test (T25FWT), the 6-minute walk test (6MWT), and the 12-item Multiple Sclerosis Walking Scale (MSWS-12). Spearman rho correlations were used to evaluate relationships between spasticity measures, measures of walking speed and endurance, and self-perceived limitations in walking. The correlation was small between PF spasticity and the T25FWT (PF maximum [Max] MAS rho = 0.27, PF Max DSM rho = 0.26), the 6MWT (PF Max MAS rho = -0.20, PF Max DSM rho = -0.21), and the MSWS-12 (PF Max MAS rho = 0.11, PF Max DSM rho = 0.26). Our results are similar to reports in other neurologic clinical populations, wherein spasticity has a limited association with walking dysfunction.

Strength and jump biomechanics of elite and recreational female youth soccer players

CONTEXT

Most researchers investigating soccer injuries have studied elite athletes because they have greater athletic-exposure hours than other athletes, but most youth participate at the recreational level. If risk factors for injury vary by soccer level, then recommendations generated using research with elite youth soccer players might not generalize to recreational players.

OBJECTIVE

To examine injury risk factors of strength and jump biomechanics by soccer level in female youth athletes and to determine whether research recommendations based on elite youth athletes could be generalized to recreational players.

DESIGN

Cross-sectional study.

SETTING

Seattle Youth Soccer Association.

PATIENTS OR OTHER PARTICIPANTS

Female soccer players (N = 92) aged 11 to 14 years were recruited from 4 randomly selected elite (n = 50; age = 12.5 years, 95% confidence interval [95% CI]) = 12.3, 12.8 years; height = 157.8 cm, 95% CI = 155.2, 160.3 cm; mass = 49.9 kg, 95% CI = 47.3, 52.6 kg) and 4 randomly selected recreational (n = 42; age = 13.2 years, 95% CI = 13.0, 13.5 years; height = 161.1 cm, 95% CI = 159.2, 163.1 cm; mass = 50.6 kg, 95% CI = 48.3, 53.0 kg) soccer teams.

MAIN OUTCOME MEASURE(S)

Players completed a questionnaire about demographics, history of previous injury, and soccer experience. Physical therapists used dynamometry to measure hip strength (abduction, adduction, extension, flexion) and knee strength (flexion, extension) and Sportsmetrics to measure vertical jump height and jump biomechanics. We compared all measurements by soccer level using linear regression to adjust for age and mass.

RESULTS

Elite players were similar to recreational players in all measures of hip and knee strength, vertical jump height, and normalized knee separation (a valgus estimate generated using Sportsmetrics).

CONCLUSIONS

Female elite youth players and recreational players had similar lower extremity strength and jump biomechanics. This suggests that recommendations generated from research with elite youth soccer players could be generalized to recreational players.

Effectiveness of resistance training in combination with botulinum toxin-A on hand and arm use in children with cerebral palsy: a pre-post intervention study

BACKGROUND

The aim of this pilot study was to examine the effects of additional resistance training after use of Botulinum Toxin-A (BoNT-A) on the upper limbs in children with cerebral palsy (CP).

METHODS

Ten children with CP (9-17 years) with unilaterally affected upper limbs according to Manual Ability Classification System II were assigned to two intervention groups. One group received BoNT-A treatment (group B), the other BoNT-A plus eight weeks resistance training (group BT). Hand and arm use were evaluated by means of the Melbourne assessment of unilateral upper limb function (Melbourne) and Assisting Hand Assessment (AHA). Measures of muscle strength, muscle tone, and active range of motion were used to assess neuromuscular body function. Measurements were performed before and two and five months after intervention start. Change scores and differences between the groups in such scores were subjected to Mann-Whitney U and Wilcoxon Signed Rank tests, respectively.

RESULTS

Both groups had very small improvements in AHA and Melbourne two months after BoNT-A injections, without differences between groups. There were significant, or close to significant, short-term treatment effects in favour of group BT for muscle strength in injected muscles (elbow flexion strength, p = .08) and non-injected muscles (elbow extension and supination strength, both p = .05), without concomitant increases in muscle tone. Active supination range improved in both groups, but more so in group BT (p = .09). There were no differences between the groups five months after intervention start.

CONCLUSIONS

Resistance training strengthens non-injected muscles temporarily and may reduce short-term strength loss that results from BoNT-A injections without increasing muscle tone. Moreover, additional resistance training may increase active range of motion to a greater extent than BoNT-A alone. None of the improvements in neuromuscular impairments further augmented use of the hand and arm. Larger clinical trials are needed to establish whether resistance training can counteract strength loss caused by BoNT-A, whether the combination of BoNT-A and resistance training is superior to BoNT-A or resistance training alone in improving active range of motion, and whether increased task-related training is a more effective approach to improve hand and arm use in children with CP.

The relationship between spasticity and muscle volume of the knee extensors in children with cerebral palsy

PURPOSE

The purpose of this study was to examine the relationship between spasticity and muscle volume in children with cerebral palsy (CP), using isokinetic dynamometry and magnetic resonance imaging.

METHODS

A retrospective sample of 8 children with diplegic CP was analyzed. One set of 10 passive knee flexion movements was completed at a velocity of 180° per second with concurrent surface electromyography of the medial hamstrings (MH) and vastus lateralis (VL) to assess knee extensor spasticity. Magnetic resonance imaging was used to measure maximum cross-sectional area and muscle volume of the quadriceps femoris.

RESULTS

The quadriceps femoris muscle volume was positively correlated with MH reflex activity, VL reflex activity, MH/VL co-contraction, and peak knee extensor passive torque (P < .05).

CONCLUSION

The present findings suggest that higher levels of knee extensor muscle spasticity are associated with greater quadriceps muscle volume in children with spastic diplegic CP.

Effects of a supported speed treadmill training exercise program on impairment and function for children with cerebral palsy

AIM

To compare the effects of a supported speed treadmill training exercise program (SSTTEP) with exercise on spasticity, strength, motor control, gait spatiotemporal parameters, gross motor skills, and physical function.

METHOD

Twenty-six children (14 males, 12 females; mean age 9y 6mo, SD 2y 2mo) with spastic cerebral palsy (CP; diplegia, n=12; triplegia, n=2; quadriplegia n=12; Gross Motor Function Classification System levels II-IV) were randomly assigned to the SSTTEP or exercise (strengthening) group. After a twice daily, 2-week induction, children continued the intervention at home 5 days a week for 10 weeks. Data collected at baseline, after 12-weeks' intervention, and 4 weeks after the intervention stopped included spasticity, motor control, and strength; gait spatiotemporal parameters; Gross Motor Function Measure (GMFM); and Pediatric Outcomes Data Collection Instrument (PODCI).

RESULTS

Gait speed, cadence, and PODCI global scores improved, with no difference between groups. No significant changes were seen in spasticity, strength, motor control, GMFM scores, or PODCI transfers and mobility. Post-hoc testing showed that gains in gait speed and PODCI global scores were maintained in the SSTTEP group after withdrawal of the intervention.

INTERPRETATION

Although our hypothesis that the SSTTEP group would have better outcomes was not supported, results are encouraging as children in both groups showed changes in function and gait. Only the SSTTEP group maintained gains after withdrawal of intervention.

Cycling with functional electrical stimulation in an adult with spastic diplegic cerebral palsy

BACKGROUND AND PURPOSE

Adults with cerebral palsy (CP) are at risk for decreased mobility and health complications, and exercise may combat some of these negative changes. Because people with CP have difficulty generating sufficient muscle force, exercise augmented with functional electrical stimulation (FES) is an option for increasing exercise intensity. This mixed-method (quantitative-qualitative) case report describes the effects-across the International Classification of Functioning, Disability and Health (ICF) model-of cycling with FES (FES cycling) in an adult with CP.

CASE DESCRIPTION

An ambulatory 49-year-old man with spastic diplegic CP cycled with FES at home for 30 minutes, 3 times per week, for 12 weeks. Volitional efforts were augmented by FES of the bilateral quadriceps, gastrocnemius, and gluteal muscles. Testing was performed before and after the intervention and 4 weeks after intervention withdrawal.

OUTCOMES

After training, quadriceps muscle strength (force-generating capacity) improved by 22.2%, hamstring muscle strength improved by 18.5%, and the Timed "Up & Go" Test time decreased from 11.9 to 9.0 seconds. The patient reported increased performance and satisfaction for self-identified goals at the ICF level of participation, and his score on the Medical Outcomes Study 36-Item Health Survey questionnaire increased from 62.1 to 77.6. However, he reported increased back pain, which he attributed to positioning while cycling. Qualitative interviews provided context (the patient's perspective) for some of the quantitative results.

DISCUSSION

The patient made gains in body structure and function, activity, and participation (ICF levels) after FES cycling. The mixed-method approach provided insight into his experiences and perceptions about the measures assessed quantitatively. Further investigation on FES cycling in this population as well as positioning during cycling is warranted.

Relationship between age and spasticity in children with diplegic cerebral palsy

OBJECTIVE

To examine the relationship between passive torque, reflex activity, co-contraction, and age during the assessment of spasticity of knee flexors and extensors in children with spastic diplegic cerebral palsy (CP).

DESIGN

Retrospective.

SETTING

Pediatric orthopedic hospital.

PARTICIPANTS

Children (N=36) with spastic diplegic CP.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Spasticity of the knee flexors and knee extensors (as measured by peak passive torque, mean passive torque, reflex activity of the medial hamstrings, reflex activity of vastus lateralis, and co-contraction) was assessed during passive movements completed using an isokinetic dynamometer with concurrent electromyography.

RESULTS

A significant positive relationship was found between age and mean knee flexor passive torque (P<.05), while a significant negative relationship was found between age and mean percentage of the range of motion with co-contraction (P<.05).

CONCLUSIONS

Our results suggest that passive stiffness may play a larger role in spasticity than reflex activity as children with spastic diplegic CP age. Additional research is needed to determine whether subject age could influence the effectiveness of interventions, such as serial casting or botulinum toxin, for spasticity in children with spastic diplegic CP.

Hand-held dynamometry in patients with haematological malignancies: measurement error in the clinical assessment of knee extension strength

BACKGROUND

Hand-held dynamometry is a portable and inexpensive method to quantify muscle strength. To determine if muscle strength has changed, an examiner must know what part of the difference between a patient's pre-treatment and post-treatment measurements is attributable to real change, and what part is due to measurement error. This study aimed to determine the relative and absolute reliability of intra and inter-observer strength measurements with a hand-held dynamometer (HHD).

METHODS

Two observers performed maximum voluntary peak torque measurements (MVPT) for isometric knee extension in 24 patients with haematological malignancies. For each patient, the measurements were carried out on the same day. The main outcome measures were the intraclass correlation coefficient (ICC +/- 95%CI), the standard error of measurement (SEM), the smallest detectable difference (SDD), the relative values as % of the grand mean of the SEM and SDD, and the limits of agreement for the intra- and inter-observer '3 repetition average' and the 'highest value of 3 MVPT' knee extension strength measures.

RESULTS

The intra-observer ICCs were 0.94 for the average of 3 MVPT (95%CI: 0.86-0.97) and 0.86 for the highest value of 3 MVPT (95%CI: 0.71-0.94). The ICCs for the inter-observer measurements were 0.89 for the average of 3 MVPT (95%CI: 0.75-0.95) and 0.77 for the highest value of 3 MVPT (95%CI: 0.54-0.90). The SEMs for the intra-observer measurements were 6.22 Nm (3.98% of the grand mean (GM) and 9.83 Nm (5.88% of GM). For the inter-observer measurements, the SEMs were 9.65 Nm (6.65% of GM) and 11.41 Nm (6.73% of GM). The SDDs for the generated parameters varied from 17.23 Nm (11.04% of GM) to 27.26 Nm (17.09% of GM) for intra-observer measurements, and 26.76 Nm (16.77% of GM) to 31.62 Nm (18.66% of GM) for inter-observer measurements, with similar results for the limits of agreement.

CONCLUSION

The results indicate that there is acceptable relative reliability for evaluating knee strength with a HHD, while the measurement error observed was modest. The HHD may be useful in detecting changes in knee extension strength at the individual patient level.

Roles of reflex activity and co-contraction during assessments of spasticity of the knee flexor and knee extensor muscles in children with cerebral palsy and different functional levels

BACKGROUND AND PURPOSE

Spasticity is a common impairment in children with cerebral palsy (CP). The purpose of this study was to examine differences in passive resistive torque, reflex activity, coactivation, and reciprocal facilitation during assessments of the spasticity of knee flexor and knee extensor muscles in children with CP and different levels of functional ability.

SUBJECTS

Study participants were 20 children with CP and 10 children with typical development (TD). The 20 children with CP were equally divided into 2 groups: 10 children classified in Gross Motor Function Classification Scale (GMFCS) level I and 10 children classified in GMFCS level III.

METHODS

One set of 10 passive movements between 25 and 90 degrees of knee flexion and one set of 10 passive movements between 90 and 25 degrees of knee flexion were completed with an isokinetic dynamometer at 15 degrees /s, 90 degrees /s, and 180 degrees /s and concurrent surface electromyography of the vastus lateralis and medial hamstring muscles.

RESULTS

Children in the GMFCS level III group demonstrated significantly more peak knee flexor torque with passive movements at 180 degrees /s than children with TD. Children in the GMFCS level I and level III groups demonstrated significantly more repetitions with medial hamstring muscle activity, vastus lateralis muscle activity, and co-contraction than children with TD during the assessment of knee flexor spasticity at a velocity of 180 degrees /s.

DISCUSSION AND CONCLUSION

Children with CP and more impaired functional mobility may demonstrate more knee flexor spasticity and reflex activity, as measured by isokinetic dynamometry, than children with TD. However, the finding of increased reflex activity with no increase in torque in the GMFCS I group in a comparison with the TD group suggests that reflex activity may play a less prominent role in spasticity.

Calf muscle volume estimates: implications for botulinum toxin treatment?

An optimal botulinum toxin dose may be related to the volume of the targeted muscle. We investigated the suitability of using ultrasound and anthropometry to estimate gastrocnemius and soleus muscle volume. Gastrocnemius and soleus muscle thickness was measured in 11 cadaveric human legs, using ultrasound. Lower leg length was tape-measured. Muscle volume was determined by water displacement of the dissected muscles. Simple and multiple regression analyses, using muscle thickness and lower leg length as independent variables, were performed to establish muscle volume prediction equations from the muscle volume measured by water displacement. Validating the equations based on simple regression analyses resulted in a correlation (r2) of 0.373 and 0.518 (P < 0.047), and a standard error of the estimate of 24.4 cm3 (11.7% of the measured mean muscle volume) and 33.2 cm3 (12.7%) for the gastrocnemius and soleus muscles, respectively. The corresponding values for the multiple regression analyses were an r2 of 0.497 and 0.650 (P < 0.017), and a standard error of the estimate of 21.9 cm3 (10.5%) and 28.4 cm3 (10.8%) for the gastrocnemius and soleus muscles, respectively. It seems possible to estimate the volume of individual plantar flexor muscles using ultrasound and anthropometry. This possibility should be investigated further in living humans.

Relationships Between Spasticity, Strength, Gait, and the GMFM-66 in Persons With Spastic Diplegia Cerebral Palsy

OBJECTIVE

To determine the relationships between spasticity, strength, and the functional measures of gait and gross motor function in persons with spastic diplegia cerebral palsy (CP).

DESIGN

Retrospective, cross-sectional study.

SETTING

Hospital clinic.

PARTICIPANTS

Ninety-seven participants (49 boys, 48 girls; mean age+/-standard deviation, 9.11+/-4.8 y) with spastic diplegia CP were tested once.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

A KinCom dynamometer was used to objectively measure spasticity (ankle plantarflexors, knee flexors, hip adductors) and maximum strength (ankle dorsiflexors and plantarflexors, knee flexors and extensors, hip abductors and adductors). A gait analysis was conducted to evaluate linear variables (gait speed, stride length, cadence) and kinematic variables (ankle dorsiflexion, foot progression, knee and hip flexion, pelvic tilt at initial contact and ankle dorsiflexion, knee and hip flexion, pelvic tilt, trunk rotation range of motion) during gait. Gross motor function was measured using the Gross Motor Function Measure (GMFM-66) and separately, the GMFM walking, running & jumping dimension. Multiple linear regression analysis was used to determine the relationships between spasticity, strength, gait, and the GMFM (P<.05).

RESULTS

Spasticity did not account for a substantial amount of explained variance in gait and gross motor function (up to 8% for the GMFM walking, running & jumping dimension). Moderate to high correlations existed between strength and gait linear data and function, accounting for up to 69% of the explained variance (strength and GMFM-66, r2=.69).

CONCLUSIONS

For this cohort of participants with spastic diplegia CP who ambulated with or without an assistive device, strength was highly related to function and explained far more of the variance than spasticity. The results may not be generalized to those with more severe forms of CP.