Associations between lower limb strength and gait velocity following stroke: A systematic review

Beyond unilateral motor impairments: Role of bilateral force control and strength asymmetry in gait coordination and falls post-stroke

Coordination between lower extremities is a fundamental aspect of walking, yet it has received limited attention in locomotor recovery post-stroke. We aimed to compare the impact of unilateral versus bilateral force impairments on gait coordination and examine the relationship between gait coordination and incidence of falls post-stroke. In adults with stroke (N = 22) and age-similar healthy controls (N = 22), we measured gait coordination with phase coordination index (PCI) during overground walking. We measured force control for ankle dorsiflexors in unilateral and bilateral conditions. Unilateral force impairments were quantified with force error during visuomotor tracking and maximum voluntary contraction force for each leg. Bilateral force impairments were measured with cross-correlation coefficient, time lag, and strength symmetry. We recorded the history of falls in the previous year for adults with stroke. Compared with controls, adults with stroke showed significantly increased PCI, decreased cross-correlation coefficient and increased time lag between bilateral forces. Force error of both paretic and non-paretic legs was increased in the stroke group. Strength symmetry and cross-correlation coefficient explained 59.5 % of the variance in PCI (p < 0.001). However, unilateral force impairments were not associated with PCI. Adults with stroke reported a previous fall incidence rate of 59.09 %. Stroke survivors with a history of fall showed significantly higher PCI relative to stroke survivors without a history of fall (p < 0.01). We found a significant relationship between falls and PCI (p < 0.05) such that poor gait coordination was related to past incidence of falls in stroke survivors. The current study provides novel insights that impairments in bilateral, but not unilateral force control influences coordination during overground walking post-stroke. Specifically, impaired timing between bilateral ankle forces and strength asymmetry negatively impacts gait coordination post-stroke. Impaired gait coordination elevates the risk for falling post-stroke, thereby compromising safe mobility in individuals with stroke.

Does spastic myopathy determine active movement and ambulation speed in chronic spastic paresis?-A cross-sectional study on plantar flexors

BACKGROUND

Functional correlates of spastic myopathy, the muscle disorder of spastic paresis, are unknown.

OBJECTIVE

To explore reciprocal relationships between clinical and structural parameters of plantar flexors with i) ambulation speed, ii) dorsiflexion and plantarflexion torques in chronic hemiparesis.

METHODS

Cross-sectional trial in chronic stroke-induced hemiparesis (>6 months). Plantar flexors were quantified through i) the Five Step Assessment: maximal extensibility (XV1), active range of dorsiflexion (XA); ii) ultrasonography: fascicle length (Lf) and thickness (Th) of medial gastrocnemius (GAS) and soleus (SOL), knee extended in an isokinetic ergometer, ankle at 80% XV1-GAS. Maximal isometric torques in plantar flexion (PF) and dorsiflexion (DF) and maximal barefoot 10-meter ambulation speed were collected. Relationships between structural, biomechanical, clinical and functional parameters were explored using non-parametric testing (Spearman).

RESULTS

Twenty-one subjects (age 58.0±8.4, mean±SD, time since lesion 7.8±5.7 years) were recruited, with the following characteristics: ambulation speed, 0.77±0.37m/sec; XV1-SOL 92.7±10.3°; XV1-GAS 91.3±9.6°; XA-SOL 86.9±10.0°; XA-GAS 7676±14.2°; LfGAS, 58.2±18.3mm; ThGAS, 17.1±3.6 mm; LfSOL, 36.0±9.6 mm; ThSOL, 13.8±3.3mm; PF peak-torque 46.5±34.1Nm, DF peak-torque, 20.1±19.1Nm. XA-SOL and XA-GAS strongly correlated with XV1-SOL and XV1-GAS respectively (ρ = 0.74, p = 4E-04; resp ρ = 0.60, p = 0.0052). Ambulation speed moderately correlated with LfGAS (ρ = 0.51, p = 0.054), ThGAS (ρ = 0.58, p = 0.02) and LfSOL (ρ = 0.63, p = 0.009). DF and PF peak-torques both correlated with LfGAS (ρ = 0.53, p = 0.04) a; resp. ρ = 0.71, p = 0.0015).

CONCLUSION

In chronic hemiparesis, active dorsiflexion is mostly determined by plantar flexor extensibility. Plantar flexor fascicle shortening is associated with reduced ambulation speed and ankle torques. Attempts to restore plantar flexor extensibility might be important objectives for gait rehabilitation in chronic hemiparesis.

Reliability of ankle dorsiflexor muscle strength, rate of force development, and tibialis anterior electromyography after stroke

Background

Measures of hemiparetic ankle dorsiflexor muscle strength and rate of force development (RFD) are often used to determine the efficacy of rehabilitation interventions after stroke. However, evidence supporting the reliability of these measures is limited. This brief report provides a secondary analysis investigating the between-session reliability of isometric ankle dorsiflexor muscle strength, rate of force development (RFD), and tibialis anterior electromyography (TA EMG), in people with chronic stroke.

Method

Participants (n=15) completed three maximal isometric contractions of the ankle dorsiflexor muscles as fast as possible using a rigid dynamometer. Tests were repeated seven days later. Outcomes included ankle dorsiflexor isometric maximal voluntary contraction (MVC), RFD in the first 200ms (RFD200ms), time to reach 90% MVC, and peak TA EMG. Data were analysed for 13 participants using intra-class correlation coefficients (ICC) and standard error of the measure percentage (SEM%).

Results

Reliability was higher when analysing the mean of three trials rather than the best of three trials. There was excellent reliability for isometric dorsiflexor MVC (ICC 0.97 [95% CI 0.92, 0.99], SEM% 7%). However, for other outcomes, while the ICC indicated good reliability, the lower bound of the 95% confidence interval of the ICC fell in the moderate range for TA EMG (ICC 0.86 [95% CI 0.60, 0.96], SEM% 25%) and time to reach 90% MVC (ICC 0.8 [95% CI 0.53, 0.93], SEM% 23%) and in the poor range for dorsiflexor RFD200ms (ICC 0.79 [95% CI 0.48, 0.92], SEM% 24%).

Conclusion

The findings raise concerns about the reliability of measures of rapid force production in the dorsiflexor muscles after stroke. Given the functional significance of the ankle dorsiflexors, larger studies should be conducted to further investigate these concerns and explore reliable methods for measuring rapid force production in the hemiparetic dorsiflexor muscles.

Recovery of walking ability in stroke patients through postacute care rehabilitation

BACKGROUND

Walking entails orchestration of the sensory, motor, balance, and coordination systems, and walking disability is a critical concern after stroke. How and to what extent these systems influence walking disability after stroke and recovery have not been comprehensively studied.

METHODS

We retrospectively analyzed patients with stroke in the Post-acute care-Cerebrovascular Diseases (PAC-CVD) program. We compared the characteristics of patient groups stratified by their ability to complete the 5-m walk test across various time points of rehabilitation. We then used stepwise linear regression to examine the degree to which each stroke characteristic and functional ability could predict patient gait performance.

RESULTS

Five hundred seventy-three patients were recruited, and their recovery of walking ability was defined by the timing of recovery in a 5-m walk test. The proportion of patients who could complete the 5-m walk test at admission, at 3 weeks of rehabilitation, at 6 weeks of rehabilitation, between 7 and 12 weeks of rehabilitation, and who could not complete the 5-m walk test after rehabilitation was 52.2%, 21.8%, 8.7%, 8.7%, and 8.6%, respectively. At postacute care discharge, patients who regained walking ability earlier had a higher chance of achieving higher levels of walking activity. Stepwise linear regression showed that Berg Balance Scale (BBS) (β: 0.011, p < .001), age (β: -0.005, p = .001), National Institutes of Health Stroke Scale (NIHSS) (6a + 6b; β: -0.042, p = .018), Mini-Nutritional assessment (MNA) (β: -0.007, p < .027), and Fugl-Meyer upper extremity assessment (FuglUE) (β: 0.002, p = .047) scores predicted patient's gait speed at discharge.

CONCLUSION

Balance, age, leg strength, nutritional status, and upper limb function before postacute care rehabilitation are predictors of walking performance after stroke.

A Comprehensive Review of Physical Therapy Interventions for Stroke Rehabilitation: Impairment-Based Approaches and Functional Goals

Stroke is the fourth leading cause of mortality and is estimated to be one of the major reasons for long-lasting disability worldwide. There are limited studies that describe the application of physical therapy interventions to prevent disabilities in stroke survivors and promote recovery after a stroke. In this review, we have described a wide range of interventions based on impairments, activity limitations, and goals in recovery during different stages of a stroke. This article mainly focuses on stroke rehabilitation tactics, including those for sensory function impairments, motor learning programs, hemianopia and unilateral neglect, flexibility and joint integrity, strength training, hypertonicity, postural control, and gait training. We conclude that, aside from medicine, stroke rehabilitation must address specific functional limitations to allow for group activities and superior use of a hemiparetic extremity. Medical doctors are often surprised by the variety of physiotherapeutic techniques available; they are unfamiliar with the approaches of researchers such as Bobath, Coulter, and Brunnstrom, among others, as well as the scientific reasoning behind these techniques.

The Effects of Trunk and Extremity Functions on Activities of Daily Living, Balance, and Gait in Stroke

OBJECTIVES

The primary aim is to investigate the effect of the trunk, upper extremity, and lower extremity functions on activities of daily living (ADL), balance, and gait. The second aim is to investigate the effect of trunk position sense on trunk control.

METHODS

Thirty-six patients with chronic stroke were included in the study. The Trunk Impairment Scale (TIS), Barthel Index (BI), Berg Balance Scale (BBS), and 2-minute walking test (2MWT) were used for the assessment of trunk function, ADL, balance, and gait respectively. The Stroke Rehabilitation Assessment of Movement upper extremity (STREAM-UE) and lower extremity (STREAM-LE) sub-scales were used to evaluate extremity functions. The trunk position sense was measured with a digital inclinometer.

RESULTS

The mean age of the participants was 58.8 ± 12.6 years. In multiple regression analysis, TIS values were found to have a positive effect on BI and BBS (p < 0.05), and STREAM-LE values have a positive effect on BBS and 2MWT (p < 0.05). STREAM-UE values were no significant effect on BI, BBS, or 2MWT (p > 0.05). Trunk position sense was found to have a positive effect on TIS (p < 0.05).

DISCUSSION

The results of this study showed that trunk functions are more related to ADL and balance than extremity functions. Therefore, trunk training should be included as a basic application in physiotherapy programs for stroke patients.

Awakening the control of the ankle dorsiflexors in the post-stroke hemiplegic subject to improve walking activity and social participation: the WAKE (Walking Ankle isoKinetic Exercise) randomised, controlled trial

Background

Stroke is the leading cause of acquired disability in France. While 90% of patients recover the ability to walk, it is often limited with a steady speed of approximately 0.7 m/s. This limitation of walking activity is partly related to a decrease in strength associated with more or less significant spasticity. In particular, it seems that the strength of the dorsiflexor muscles is directly related to walking speed. We hypothesise that a protocol based on gestural repetition targeted at the ankle during the subacute phase potentiates the recovery of motor control, improving walking activity, and participates in recovering better social participation.

Methods

An estimated total of 60 patients with subacute stroke will be recruited to participate in this multicentre, interventional, prospective, randomised controlled trial.

All participants will benefit from conventional rehabilitation. In addition, the experimental group will take part in an ankle isokinetic rehabilitation programme for 6 weeks (at least 25 sessions). The control group will receive the same duration of conventional rehabilitation.

The primary outcome measure will be a 10-m walking speed at post-intervention. Secondary outcomes will include social participation, walking spatio-temporal parameters, and dorsiflexor strength. Outcome measurements will be taken at baseline, immediately after treatment (6 weeks), then at 6 months and 1 year of follow-up.

Discussion

This study aims to provide scientific evidence that a protocol based on an early over-solicitation of the ankle dorsiflexor muscles to promote their “awakening” can serve to achieve a more effective walking activity, which in turn encourages social participation following discharge from the hospital.

This protocol should also help optimise physical medicine and rehabilitation practices: the more systematic use of the isokinetic dynamometer as a technique associated with, and integrated into the conventional rehabilitation protocol would allow an objective evaluation of the rehabilitation benefits and should increase the rehabilitation gain in central nervous system disorders.

Trial registration

Limoges University Hospital is the sponsor of this research (Unique Protocol ID: 87RI18_0010)

This research is supported by the French Ministry of Health (PHRC 2020-A03328-31) and is conducted with the support of DGOS (PHRC interregional – GIRCI SOHO).

The study protocol was approved by the French Human Subjects Protection Review Board (Comité de Protection des Personnes Nord-Ouest III) on February 23, 2021.

The trial was registered in the ClinicalTrials.gov registry (NCT04800601) on March 16, 2021.

The Relationship Between Strength of the Affected Leg and Walking Speed After Stroke Varies According to the Level of Walking Disability: A Systematic Review

OBJECTIVE

The objectives of this review were to determine the relationship between muscle strength of the affected leg and walking speed after stroke and whether this relationship varied according to muscle group or level of walking disability.

METHODS

This systematic review with meta-analysis focused on observational studies of adult survivors of stroke. Muscle strength had to be measured as maximum voluntary force production during an isometric contraction of the affected leg. Walking had to be measured as walking speed. Studies had to report correlations between muscle strength and walking speed.

RESULTS

Thirty studies involving 1001 participants were included. Pooled mean correlations between muscle strength of the affected leg and walking speed was 0.51 (95% CI = 0.45 to 0.57). Pooled correlations between the strength of individual muscle groups and walking speed ranged from 0.42 (for the hip abductors) to 0.57 (for the ankle dorsiflexors). The correlation between level of walking disability and the mean correlation between muscle strength and walking speed was -0.70 (95% CI = -0.42 to -0.86).

CONCLUSION

After stroke, there is a strong relationship between strength of the affected leg and walking speed, with little variability across individual muscle groups. However, the level of walking disability of people with stroke does make a difference such that the more disabled people are, the stronger the relationship is between strength of the affected leg and walking speed.

IMPACT

This study suggests that the strength of all muscles of the affected leg is important for walking after stroke. It appears that increasing strength in the affected leg could be most important in people who are more disabled.

LAY SUMMARY

After stroke, the speed at which a person can walk is highly associated with the muscle strength of their affected leg. In people whose walking speed is severely affected, this association is stronger, and the physical therapist might focus on strengthening that leg so the individual can walk faster.

Correlation between cardiopulmonary metabolic energy cost and lower-limb muscle activity during inclined treadmill gait in older adults

BACKGROUND

Inclined walking requires more cardiopulmonary metabolic energy and muscle strength than flat-level walking. This study sought to investigate changes in lower-limb muscle activity and cardiopulmonary metabolic energy cost during treadmill walking with different inclination grades and to discern any correlation between these two measures in older adults.

METHODS

Twenty-four healthy older adults (n = 11 males; mean age: 75.3 ± 4.0 years) participated. All participants walked on a treadmill that was randomly inclined at 0% (condition 1), 10% (condition 2), and 16% (condition 3) for five minutes each. Simultaneous measurements of lower-limb muscle activity and cardiopulmonary metabolic energy cost during inclined treadmill walking were collected. Measured muscles included the rectus abdominis (RA), erector spinae (ES), rectus femoris (RF), biceps femoris (BF), vastus medialis (VM), tibialis anterior (TA), medial head of the gastrocnemius (GCM), and soleus (SOL) muscles on the right side.

RESULTS

As compared with 0% inclined treadmill gait, the 10% inclined treadmill gait increased the net cardiopulmonary metabolic energy cost by 22.9%, while the 16% inclined treadmill gait increased the net cardiopulmonary metabolic energy cost by 44.2%. In the stance phase, as the slope increased, activity was significantly increased in the RA, RF, VM, BF, GCM, and SOL muscles. In the swing phase, As the slope increased activity was significantly increased in the RA, RF, VM, BF, and TA muscles. SOL muscle activity was most relevant to the change in cardiopulmonary metabolic energy cost in the stance phase of inclined treadmill walking. The relationship between the increase in cardiopulmonary metabolic energy cost and changes in muscle activity was also significant in the VM, GCM, and RF.

CONCLUSION

This study demonstrated that changes in SOL, VM, GCM, and RA muscle activity had a significant relationship with cardiopulmonary metabolic energy cost increment during inclined treadmill walking. These results can be used as basic data for various gait-training programs and as an indicator in the development of assistive algorithms of wearable walking robots for older adults.

TRIAL REGISTRATION

Clinical trials registration information: ClinicalTrials.gov Identifier: NCT04614857 (05/11/2020).

Targeted verbal cues can immediately alter gait following stroke

Background: Physical therapists use verbal cueing extensively during gait rehabilitation. Nevertheless, little is known about the ability of individuals post-stroke to make immediate changes to targeted spatiotemporal gait parameters from verbal commands. Additionally, adequate muscle strength may be necessary to promote positive alterations in gait.Objectives: To determine the influence of targeted verbal cues on spatiotemporal gait parameters for individuals with chronic stroke. Further, we assessed the potential of a relationship between cue-induced gait modifications and paretic lower limb strength.Methods: Using a within-subjects design, twenty-seven adults with chronic stroke walked over a pressure mat with verbal cues to walk at (1) comfortable and (2) fast speeds, with increased (3) arm swing, (4) foot height, (5) step length, (6) push off, and (7) cadence. We also assessed lower extremity strength using a hand-held dynamometer. We measured gait speed, step length, stance time, and cadence for comparisons between conditions and performed correlational analyses to assess the influence of strength on gait alterations.Results: Specific cues elicited increased walking speed, cadence, step lengths and paretic limb stance time. Only greater paretic hip and knee flexion strength was related to the ability to increase cadence when cued to do so (r > 0.41).Conclusion: With targeted verbal cueing, clinicians can improve step length, gait speed, stance time and cadence for individuals with chronic stroke. Lower extremity strength does not appear to be related to the ability to alter gait with verbal cueing in individuals with chronic stroke.

Association of affected lower limb flexor muscle strength with swing phase duration and gait speed in elderly post-stroke patients

BACKGROUND

Although several studies have shown an association of muscle weakness with gait speed (GS), no study has explored the relationship of muscle strength with swing phase duration and GS after stroke among the elderly in Saudi Arabia.

OBJECTIVE

To examine the association of affected ankle dorsiflexor and hip flexor muscle strength with swing phase duration and GS in the elderly with different stroke chronicity.

METHODS

In this cross-sectional study, we included a total of 60 post-stroke patients aged ≥55 years who were admitted in neurorehabilitation units between May 2017 and August 2018. Linear regression was employed to examine the association of muscle strength (measured using a handheld dynamometer) with swing phase duration and GS (both measured using the computerized Zebris-Mat).

RESULTS

The chronicity of the stroke was negatively associated (p < 0.05) with swing phase duration. The ankle dorsiflexor muscle strength was significantly associated with GS (β= 0.656, p = 0.041). In contrast, hip flexor muscle strength was significantly associated with GS (β= 0.574, p < 0.0001) even after adjusting for stroke chronicity (β= 0.561, p < 0.0001).

CONCLUSIONS

Stroke chronicity was the predictor that reduced swing phase duration. The ankle dorsiflexor muscle strength was associated with GS. However, the hip flexor muscle strength was associated with GS even after adjusting for stroke chronicity.

Impaired Firing Behavior of Individually Tracked Paretic Motor Units During Fatiguing Contractions of the Dorsiflexors and Functional Implications Post Stroke

Introduction: This study quantified stroke-related changes in the following: (1) the averaged discharge rate of motor units (individually tracked and untracked) identified from high-density electromyography (HD-EMG) recordings, (2) global muscle EMG properties of the dorsiflexors during a fatiguing contraction, and the relationship between task endurance and measures of leg function.

Methods: Ten individuals with chronic stroke performed a sustained sub-maximal, isometric, fatiguing dorsiflexion contraction in paretic and non-paretic legs. Motor-unit firing behavior, task duration, maximal voluntary contraction strength (MVC), and clinical measures of leg function were obtained.

Results: Compared to the non-paretic leg, the paretic leg task duration was shorter, and there was a larger exercise-related reduction in motor unit global rates, individually tracked discharge rates, and overall magnitude of EMG. Task duration of the paretic leg was more predictive of walking speed and lower extremity Fugl-Meyer scores compared to the non-paretic leg.

Discussion: Paretic leg muscle fatigability is increased post stroke. It is characterized by impaired rate coding and recruitment and relates to measures of motor function.

Modifiable Factors Associated With Poststroke Physical Activity at Discharge From Rehabilitation: Prospective Cohort Study

BACKGROUND

People with stroke are not meeting recommended levels of physical activity. The modifiable factors associated with poststroke physical activity levels need to be identified to develop targeted interventions.

OBJECTIVE

The objective of this study was to investigate the factors at discharge from inpatient rehabilitation that are associated with physical activity levels at 3 months following discharge.

DESIGN

This was a prospective cohort study.

METHODS

Sixty-four people with stroke completed baseline assessments at discharge from inpatient rehabilitation and 55 completed the follow-up 3 months later. The candidate factors (ie, gait speed, balance, strength, cognition, mood, and motivation) were measured at discharge. The primary outcome measure at follow-up was walking-related activity (measured by wrist-worn accelerometer). Secondary outcome measures were physical activity participation (Activity Card Sort) and intensity of physical activity (International Physical Activity Questionnaire-Short 7 days). Adjusted separate multivariable linear regression models or proportional odds regression models were used to evaluate the associations between candidate factors and physical activity.

RESULTS

Gait speed and balance were associated with all aspects of physical activity. Higher level of intrinsic motivation was also associated with higher physical activity participation. Anxiety demonstrated a significant nonlinear relationship with physical activity participation.

LIMITATIONS

Inclusion of fatigue and individual muscle strength could have provided further insights into associations with steps per day.

CONCLUSION

The results demonstrated that better physical function at discharge from inpatient rehabilitation was associated with future increased levels of physical activity. Additionally, higher levels of motivation impacted on increased physical activity participation. The influence of anxiety on physical activity participation requires further exploration. Mixed-method study designs can be utilized to further understand the factors associated with poststroke physical activity.

Gait Velocity and Joint Power Generation After Stroke: Contribution of Strength and Balance

OBJECTIVE

The aim of the study was to assess the degree to which isometric strength of multiple lower limb muscle groups and balance is associated with gait velocity and joint power generation during gait after stroke.

DESIGN

Sixty-three participants in a multisite, multinational, cross-sectional, observational study underwent assessment of gait velocity (10-m walk test), standing balance (computerized posturography), and isometric strength (hand-held dynamometry). Twenty-seven participants had joint power generation assessed (three-dimensional gait analysis). Bivariate associations were examined using Spearman's correlations. Regression models with partial F tests were used to compare the contribution to gait between measures.

RESULTS

Although all muscle groups demonstrated significant associations with gait velocity (ρ = 0.40-0.72), partial F tests identified that ankle plantar flexor and hip flexor strength made the largest contribution to gait velocity. Ankle plantar flexor strength also had strong associations with habitual and fast-paced ankle power generation (ρ = 0.65 and 0.75). Balance had significant associations with habitual and fast gait velocity (ρ = -0.57 and -0.53), with partial F tests showing that the contribution was independent of strength.

CONCLUSIONS

Ankle plantar flexor and hip flexor strength had the largest contribution to gait velocity. Future research may wish to refocus strength assessment and treatment to target the ankle plantar flexors and hip flexors.

TO CLAIM CME CREDITS

Complete the self-assessment activity and evaluation online at http://www.physiatry.org/JournalCME CME OBJECTIVES: Upon completion of this article, the reader should be able to: (1) Differentiate the contribution that lower limb strength of each muscle group has on gait velocity after stroke; (2) Appraise the relationship between isometric strength and joint power generation during gait; and (3) Interpret the contribution of both strength and balance to gait after stroke.

LEVEL

Advanced ACCREDITATION: The Association of Academic Physiatrists is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.The Association of Academic Physiatrists designates this Journal-based CME activity for a maximum of 1.0 AMA PRA Category 1 Credit(s). Physicians should only claim credit commensurate with the extent of their participation in the activity.

Effect of Underwater Treadmill Gait Training With Water-Jet Resistance on Balance and Gait Ability in Patients With Chronic Stroke: A Randomized Controlled Pilot Trial

Objective: The purpose of this study was to determine the effects of underwater treadmill gait training with water-jet resistance and underwater treadmill gait training with ankle weights on balance and gait abilities in chronic stroke patients.

Methods: Twenty-two inpatients and outpatients with stroke-induced impairments were randomly assigned into two groups: an underwater treadmill gait training with water-jet resistance group (n = 11) and an underwater treadmill gait training with ankle weights group (n = 11). Participants received conventional physical therapy for 30 min and underwater treadmill gait training with water-jet resistance or ankle weights for 30 min. Intervention was performed 5 days a week for 4 weeks. The Balance System SD was used to assess static and dynamic balance. The GAITRite system was used to assess gait velocity, cadence, step length, stride length, and swing phase. All measurements were performed at the beginning of the study and 4 weeks after the intervention.

Results: The water-jet resistance group and ankle weights group showed significant improvement in static balance (P < 0.00 vs. P = 0.01), dynamic balance (P < 0.00 vs. P = 0.57), gait velocity (P < 0.00 vs. P = 0.037), cadence (P < 0.00 vs. P = 0.001), step length (P < 0.00 vs. P = 0.003), stride length (P < 0.00 vs. P = 0.023), and swing phase (P < 0.00 vs. P < 0.00). However, the static and dynamic balance ability score (P < 0.00), gait velocity (P < 0.00), cadence (P < 0.00), step length (P < 0.00), stride length (P < 0.00), and swing phase (P = 0.023) in the group that received underwater treadmill gait training with water-jet resistance improved more than in the group that received underwater treadmill gait training with ankle weights.

Conclusions: Our results demonstrated that underwater treadmill gait training with water-jet resistance is effective in improving static and dynamic balance as well as gait abilities in chronic stroke patients. Thus, training using underwater treadmill gait training with water-jet resistance may be useful in facilitating active rehabilitation in chronic stroke patients.

Does grip strength predict lower limb global strength in subjects with stroke?

Abstract Introduction: Grip strength is an important clinical measure and has been used for several purposes in different populations, including those to predict the global strength of lower limbs (LL) and upper limbs. However, little is known about the association between grip strength and lower limb (LL) global strength in subjects with stroke. Objective: To investigate the relationship between grip strength and LL global strength in stroke with subjects at both subacute and chronic phases. Method: Measures of grip strength (handgrip dynamometer) and LL global strength (hand-held dynamometer) were obtained in 20 subjects in the subacute phase of the stroke and 18 in the chronic phase. Pearson correlation coefficient was used to investigate the correlation between grip strength and LL global strength (α = 0.05). Results: Subjects in the subacute phase showed a moderate statistically significant correlation between paretic grip strength and global strength of the non-paretic LL (r = 0.50; p < 0.05), but no correlation with the paretic LL was found (p = 0.25). The non-paretic grip strength showed no statistically significant correlation with global strength of the paretic LL (p = 0.93) and of the non-paretic LL (p = 0.64). In chronic subjects, no statistically significant correlation (0.50 ≤ p ≤ 0.97) was observed. Conclusion: Grip strength does not seem to be an adequate indicator to predict LL global strength of subjects with stroke. This conclusion is different from that obtained for other populations.

Association of renal function with ambulation in mild acute stroke patients

Background: Renal dysfunction has affected the functional outcome after stroke. However, the association of renal function with walking endurance after stroke is poorly understood. Objectives: This study aimed to investigate the relationship between renal function and walking endurance and speed in mild acute stroke patients. Methods: Eighty-nine patients with mild acute stroke were enrolled. Walking endurance and speed were assessed by the 6-minute walk test (6MWT) and comfortable and maximal 10-meter walk tests (10MWT) within 7 days of hospital admission. Stroke severity was assessed using the National Institutes of Health stroke scale (NIHSS) on admission. The estimated glomerular filtration rate (eGFR) was calculated based on creatinine levels as a renal function. Pearson's correlation coefficients were calculated between eGFR and walking ability. Multivariate regression analysis was used to investigate the relationship between eGFR and walking ability in mild acute stroke patients. Results: The 6MWT distance was significantly correlated with eGFR (r = 0.212, p = .046). On multivariate regression analysis, the 6MWT was significantly associated with age (p = .029), body mass index (p = .020), NIHSS score (p = .016), and eGFR (p = .028), whereas the comfortable 10MWT was significantly associated with the NIHSS score alone (p = .009) and the maximal 10MWT was significantly associated with age (p = .032) and NIHSS score (p = .007). Conclusion: The eGFR based on creatinine levels of acute stroke patients may be important factor to predict the walking endurance in mild acute stroke patients.

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

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

Cryotherapy reduces muscle hypertonia, but does not affect lower limb strength or gait kinematics post-stroke: a randomized controlled crossover study

BACKGROUND

Based on the premise that spasticity might affect gait post-stroke, cryotherapy is among the techniques used to temporarily reduce spasticity in neurological patients. This effective technique would enhance muscle performance, and ultimately, functional training, such as walking. However, understanding whether a decrease in spasticity level, if any, would lead to improving muscle performance and gait parameters is not based on evidence and needs to be clarified.

OBJECTIVES

to investigate the immediate effects of cryotherapy, applied to spastic plantarflexor muscles of subjects post-stroke, on tonus level, torque generation capacity of plantarflexors and dorsiflexors, and angular/spatiotemporal gait parameters.

METHODS

Sixteen chronic hemiparetic subjects participated in this randomized controlled crossover study. Cryotherapy (ice pack) or Control (room temperature sand pack) were applied to the calf muscles of the paretic limb. The measurements taken (before and immediately after intervention) were: 1) Tonus according to the Modified Ashworth Scale; 2) Torque assessments were performed using an isokinetic dynamometer; and 3) Spatiotemporal and angular kinematics of the hip, knee, and ankle (flexion/extension), obtained using a tridimensional movement analysis system (Qualisys).

RESULTS

Cryotherapy decreased plantarflexor tonus but did not change muscle torque generation capacity and did not affect spatiotemporal or angular parameters during gait compared to control application. These findings contribute to the evidence-based approach to clinical rehabilitation post-stroke.

CONCLUSIONS

The findings of this study suggest that cryotherapy applied to the calf muscles of subjects with chronic hemiparesis reduces muscle hypertonia but does not improve dorsiflexors and plantarflexors performance and gait parameters.

Walking speed best explains perceived locomotion ability in ambulatory people with chronic stroke, assessed by the ABILOCO questionnaire

BACKGROUND

The identification of the predictors of locomotion ability could help professionals select variables to be considered during clinical evaluations and interventions.

OBJECTIVE

To investigate which impairment measures would best predict locomotion ability in people with chronic stroke.

METHODS

Individuals (n=115) with a chronic stroke were assessed. Predictors were characteristics of the participants (i.e. age, sex, and time since stroke), motor impairments (i.e. muscle tonus, strength, and motor coordination), and activity limitation (i.e. walking speed). The outcome of interest was the ABILOCO scores, a self-reported questionnaire for the assessment of locomotion ability, designed specifically for individuals who have suffered a stroke.

RESULTS

Age, sex, and time since stroke did not significantly correlate with the ABILOCO scores (-0.07<ρ<0.05; 0.48<p<0.99). Measures of motor impairments and walking speed were significantly correlated with the ABILOCO scores (-0.25<r<0.57; p<0.001), but only walking speed and strength were kept in the regression model. Walking speed alone explained 35% (F=55.5; p<0.001) of the variance in self-reported locomotion ability. When strength was included in the model, the explained variance increased to 37% (F=31.4; p<0.001).

CONCLUSIONS

Walking speed and lower limb strength best predicted locomotion ability as perceived by individuals who have suffered a stroke.

Gait Impairments in Patients Without Lower Limb Hypertonia Early Poststroke Are Related to Weakness of Paretic Knee Flexors

OBJECTIVE

To describe gait characteristics of patients without clinical evidence of lower limb hypertonia within 2 months of stroke and explore the relationship between gait and residual motor function.

DESIGN

Cohort study.

SETTING

Motion analysis laboratory in a tertiary-care free-standing rehabilitation hospital.

PARTICIPANTS

Consecutive sample of 73 eligible inpatients (first-known stroke <2 months postonset, walking independently, modified Ashworth score of 0 in the paretic lower limb) and 27 healthy controls (N=100).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Gait speed, stride and step lengths and cadences, stance time, single-support and double-support times, and associated symmetry measures in patients at self-selected normal speed and controls at very slow speed (51.1±32.6 cm/s and 61.9±21.8 cm/s, respectively, P=.115); Fugl-Meyer lower extremity motor score (FM-LE) and isometric knee flexion and extension strength in patients.

RESULTS

Except the stride/step cadence, all temporospatial parameters significantly differed between the stroke and control participants. Furthermore, significantly greater asymmetries were found in the patients for the overall stance time, initial double-support and single-support times, and step cadence, reflecting smaller values in the paretic than nonparetic limb. Most temporospatial parameters moderately to strongly correlated with the gait speed (|r|: .72-.94, P<.0001), FM-LE (|r|: .42-.62, P≤.0005), and paretic knee flexor strength (|r|: .47-.57, P≤.0004).

CONCLUSIONS

Gait of patients without clinical evidence of lower limb hypertonia within 2 months of stroke is characterized by many temporospatial deviations and asymmetries. The self-selected normal gait speed, FM-LE, and paretic knee flexor strength can discriminate gait impairments in these patients shortly before inpatient discharge. It remains to be determined whether the observed relationships between paretic knee flexor strength and gait measures warrant the development of interventions for strengthening of the paretic knee flexors in order to improve gait early poststroke.

Strength of the lower limb and trunk muscles is associated with gait speed in individuals with sub-acute stroke: a cross-sectional study

OBJECTIVES

To investigate the association between measures of strength of the lower limb and trunk muscles and gait speed and to identify the muscle group that would best predict gait speed in individuals with sub-acute stroke.

METHODS

Using a cross-sectional observational study design, forty-four individuals with sub-acute stroke (62 years, SD=14; 4 months, SD=1 post-stroke) were assessed. The evaluations were performed at a university laboratory, participants' homes, or community-based settings. Bilateral maximum isometric strength (hip, knee, and ankle flexors/extensors, hip abductors, trunk flexors/extensors, and trunk lateral flexors and rotators) was measured using a portable dynamometer. Comfortable and maximum gait speeds were measured using the 10-m walk test.

RESULTS

Weak to moderate associations were found between measures of strength of the lower limb muscles and comfortable (0.36≤r≤0.53; p<0.05) and maximum (0.37≤r≤0.59; p<0.05) gait speeds, except for the non-paretic knee flexors and comfortable gait speed (p=0.06). Weak to moderate associations were also found between measures of strength of the trunk muscles and comfortable (0.39≤r≤0.50; p<0.05) and maximum (0.39≤r≤0.61; p<0.05) gait speeds. Stepwise multiple regression analyses revealed that the non-paretic dorsiflexors and the left lateral trunk flexors explained 29% and 42% of the variance in the maximum and comfortable gait speeds, respectively.

CONCLUSIONS

The strength of the lower limb and trunk muscles was positively associated with comfortable and maximum gait speeds. The muscle strength of the non-paretic dorsiflexors and the left lateral trunk flexors might have a role to play in determining comfortable and maximum gait speeds of individuals with sub-acute stroke.

Knee extensor muscles strength indicates global lower-limb strength in individuals who have suffered a stroke: A cross-sectional study

OBJECTIVES

This study had three aims: (1) to evaluate the relationships between the paretic knee extensor muscle strength and global lower-limb strength in individuals who had suffered a sub-acute/chronic stroke, (2) to determine whether global lower-limb strength, sex, body mass index, or age could predict knee extensor muscle strength, and 3) to investigate whether the results obtained via a Modified Sphygmomanometer Test (MST) would be similar to those obtained using a hand-held dynamometer.

METHODS

This was a cross-sectional study, performed at a research laboratory, at participants' homes, or at outpatient clinics. Forty-two individuals with a sub-acute stroke and 45 individuals with a chronic stroke participated. Maximum isometric strength of the paretic lower-limb muscles (i.e. hip, knee, and ankle flexors/extensors, hip abductors) was measured using the MST and a hand-held dynamometer.

RESULTS

Significant and high correlation coefficients were found between knee extensor muscle strength and global lower-limb strength as measured by the combined strength values of 6 lower limb muscle groups in individuals with sub-acute (0.81≤r≤0.88; p<0.05) and chronic (0.82≤r≤0.85; p<0.05) stroke. Step-wise multiple regression analysis revealed that only global lower-limb strength was retained in the model and accounted for 66-78% and 67-72% (p<0.001) of the variance in knee extensor muscle strength at the sub-acute and chronic phases post-stroke, respectively. The results obtained via the MST were similar to those obtained using the hand-held dynamometer.

CONCLUSION

Paretic knee extensor muscles strength, assessed using a MST or a hand-held dynamometer, indicates global lower-limb strength in individuals with a sub-acute or chronic stroke.

Reliability and validity of the Wii Balance Board for assessment of standing balance: A systematic review

The use of force platform technologies to assess standing balance is common across a range of clinical areas. Numerous researchers have evaluated the low-cost Wii Balance Board (WBB) for its utility in assessing balance, with variable findings. This review aimed to systematically evaluate the reliability and concurrent validity of the WBB for assessment of static standing balance. Articles were retrieved from six databases (Medline, SCOPUS, EMBASE, CINAHL, Web of Science, Inspec) from 2007 to 2017. After independent screening by two reviewers, 25 articles were included. Two reviewers performed the data extraction and quality assessment. Test-retest reliability was investigated in 12 studies, with intraclass correlation coefficients or Pearson's correlation values showing a range from poor to excellent reliability (range: 0.27 to 0.99). Concurrent validity (i.e. comparison with another force platform) was examined in 21 studies, and was generally found to be excellent in studies examining the association between the same outcome measures collected on both devices. For studies reporting predominantly poor to moderate validity, potentially influential factors included the choice of 1) criterion reference (e.g. not a common force platform), 2) test duration (e.g. <30 s for double leg), 3) outcome measure (e.g. comparing a centre of pressure variable from the WBB with a summary score from the force platform), 4) data acquisition platform (studies using Apple iOS reported predominantly moderate validity), and 5) low sample size. In conclusion, evidence suggests that the WBB can be used as a reliable and valid tool for assessing standing balance. Protocol registration number: PROSPERO 2017: CRD42017058122.

Motor Imagery Training on Muscle Strength and Gait Performance in Ambulant Stroke Subjects-A Randomized Clinical Trial

INTRODUCTION

The ultimate goal of physiotherapy in stroke rehabilitation is focused towards physical independence and to restore their functional ability during activities of daily living (ADLs). Motor imagery (MI) is an active process during which a specific action is reproduced within working memory without any actual movements. MI training enhances motor learning, neural reorganization and cortical activation in stroke. The efficacy of MI training involving lower extremity mobility tasks need to be assessed.

AIM

To evaluate the effects of combining motor imagery with physical practice in paretic Lower Extremity Muscles Strength and Gait Performance in Ambulant Stroke subjects.

MATERIALS AND METHODS

A Randomized Clinical Trial was conducted in Department of Physical Therapy, Tertiary Care Hospitals, Mangalore, India which includes 40 hemi paretic subjects (>3 months post-stroke) who were ambulant with good imagery ability in both KVIQ-20 ≥ 60 and Time dependent MI screening test were recruited and randomly allocated into task-oriented training group (n=20) and task-oriented training group plus MI group (n=20). Subjects in both groups underwent task orientated training for lower extremity 45-60 minutes, 4 days per week for 3 weeks. In addition, the experimental group received 30 minutes of audio-based lower extremity mobility tasks for MI practice. Isometric muscle strength of Hip, Knee and Ankle using a hand-held dynamometer and self-selected 10 m gait speed were assessed before and after 3 weeks of intervention.

RESULTS

Both the groups had found a significant change for all the outcome measures following 3 weeks of interventions with p <.05. The experimental group had shown a significant improvement in paretic hip muscles (both flexors and extensors), knee extensors and ankle dorsiflexors and gait speed compare to control group with p < .05 between group analyses.

CONCLUSION

Additional task specific MI training improves paretic muscle strength and gait performance in ambulant stroke patients.

Assessment of Lower Limb Muscle Strength and Power Using Hand-Held and Fixed Dynamometry: A Reliability and Validity Study

Introduction

Hand-held dynamometry (HHD) has never previously been used to examine isometric muscle power. Rate of force development (RFD) is often used for muscle power assessment, however no consensus currently exists on the most appropriate method of calculation. The aim of this study was to examine the reliability of different algorithms for RFD calculation and to examine the intra-rater, inter-rater, and inter-device reliability of HHD as well as the concurrent validity of HHD for the assessment of isometric lower limb muscle strength and power.

Methods

30 healthy young adults (age: 23±5yrs, male: 15) were assessed on two sessions. Isometric muscle strength and power were measured using peak force and RFD respectively using two HHDs (Lafayette Model-01165 and Hoggan microFET2) and a criterion-reference KinCom dynamometer. Statistical analysis of reliability and validity comprised intraclass correlation coefficients (ICC), Pearson correlations, concordance correlations, standard error of measurement, and minimal detectable change.

Results

Comparison of RFD methods revealed that a peak 200ms moving window algorithm provided optimal reliability results. Intra-rater, inter-rater, and inter-device reliability analysis of peak force and RFD revealed mostly good to excellent reliability (coefficients ≥ 0.70) for all muscle groups. Concurrent validity analysis showed moderate to excellent relationships between HHD and fixed dynamometry for the hip and knee (ICCs ≥ 0.70) for both peak force and RFD, with mostly poor to good results shown for the ankle muscles (ICCs = 0.31–0.79).

Conclusions

Hand-held dynamometry has good to excellent reliability and validity for most measures of isometric lower limb strength and power in a healthy population, particularly for proximal muscle groups. To aid implementation we have created freely available software to extract these variables from data stored on the Lafayette device. Future research should examine the reliability and validity of these variables in clinical populations.