Effects of Changes in Ankle Joint Angle on the Relation Between Plantarflexion Torque and EMG Magnitude in Major Plantar Flexors of Male Chronic Stroke Survivors

Our objective in this study was to assess passive mechanical stiffness in the ankle of chronic hemiparetic stroke survivors and to compare it with those of healthy young and older (age-matched) individuals. Given the importance of the ankle during locomotion, an accurate estimate of passive ankle stiffness would be valuable for locomotor rehabilitation, potentially providing a measure of recovery and a quantitative basis to design treatment protocols. Using a novel ankle robot, we characterized passive ankle stiffness both in sagittal and in frontal planes by applying perturbations to the ankle joint over the entire range of motion with subjects in a relaxed state. We found that passive stiffness of the affected ankle joint was significantly higher in chronic stroke survivors than in healthy adults of a similar cohort, both in the sagittal as well as frontal plane of movement, in three out of four directions tested with indistinguishable stiffness values in plantarflexion direction. Our findings are comparable to the literature, thus indicating its plausibility, and, to our knowledge, report for the first time passive stiffness in the frontal plane for persons with chronic stroke and older healthy adults.

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Tendon elongation influences the amplitude of interpolated doublets in the assessment of activation in elderly men

Journal of Applied Physiology ◽

10.1152/japplphysiol.00774.2004 ◽

2005 ◽

Vol 98 (1) ◽

pp. 221-226 ◽

Cited By ~ 38

Author(s):

Christopher I. Morse ◽

Jeanette M. Thom ◽

Karen M. Birch ◽

Marco V. Narici

Keyword(s):

Ankle Joint ◽

Joint Angle ◽

Plantar Flexion ◽

Negative Association ◽

Plantar Flexors ◽

Joint Angles ◽

Elderly Men ◽

Electromechanical Delay ◽

Tendon Elongation ◽

Voluntary Contractions

This study investigated the influence of tendon elongation (TE) on postcontraction doublet (PCD) torque in the assessment of activation in the plantar flexors of nine elderly men (EM, age 73.7 ± 3.6 yr) and nine young men (YM, age 24.7 ± 4.7 yr). Plantar flexion maximal voluntary contractions (MVC) and activation were assessed at ankle joint angles of −20° (dorsiflexion), 0°, and 20° (plantar flexion). Across the ankle joint angles tested, compared with YM, the EM had a 36–49% lower plantar flexion MVC ( P < 0.01), TE was greater by 25–31% ( P < 0.01), and electromechanical delay was 65–108% greater ( P < 0.01). Activation (PCD torque to interpolated doublet torque) was 15% lower in EM compared with YM at −20° ( P < 0.05), but no different at 0 and 20°. In the EM, PCD torque relative to MVC torque was significantly lower at 20° compared with 0° ( P < 0.05). Electromechanical delay was positively correlated with TE ( R2 = 0.489, P < 0.01). In conclusion, this investigation demonstrates that, although a negative association exists between TE and PCD torque, the consequence of a greater TE on the estimation of activation in EM is negligible. This is due to a greater influence of ankle joint angle on the occlusion of a superimposed doublet, which counteracts the lesser influence of joint angle on TE and PCD torque. However, a greater TE in EM was found to significantly increase electromechanical delay, which is expected to influence the time needed for postural readjustments.

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Stroke Sarcopenia Patients Cause Weakness and Atrophy in the Knee and Ankle Joints

Current Developments in Nutrition ◽

10.1093/cdn/nzaa043_065 ◽

2020 ◽

Vol 4 (Supplement_2) ◽

pp. 214-214

Author(s):

Yamanoi Jyunya

Keyword(s):

Knee Joint ◽

Ankle Joint ◽

Muscle Weakness ◽

Muscle Atrophy ◽

Lower Limb ◽

Chronic Stroke ◽

Triceps Surae ◽

Stroke Survivors ◽

Lower Limb Muscle ◽

Limb Muscle

Abstract Objectives Chronic stroke survivors tend to be inactive, often with sarcopenia, and have decreased physical function and activities of daily living. Muscle atrophy and weakness differ between sarcopenia patients and stroke patients. Therefore, it is difficult to evaluate physiotherapy and intervention for sarcopenic patients with stroke. The purpose of this study was to identify muscles that cause muscle weakness and muscle atrophy in stroke sarcopenia patients. Methods The subjects were 117 chronic stroke survivors who were 65 years or older. Subjects were determined using the criteria of the Asian Working Group on Sarcopenia in 2019 to determine the presence of sarcopenia and were classified into sarcopenia group (SG, n = 60) and non sarcopenia group (nSG, n = 57). Atrophy assessments obtained unaffected lower limb muscle thickness (iliopsoas, gluteus maximus, gluteus medius, hamstrings, quadriceps femoris, tibialis anterior, triceps surae) using B-mode of transverse ultrasound imaging. Strength assessments obtained unaffected lower limb muscle strength (flexion, extension, abduction, adduction, external rotation and internal rotation of hip joint, flexion and extension of knee joint, planter flexion and dorsiflexion of ankle joint) using handheld dynamometer. We conducted a Student's t-test to compare the two groups. A P-value of <0.05 was considered to show statistical significance for all analyses. When the significance level is less than 0.05, the power is also calculated, and it is considered that the significant difference can be secured when P < 0.05 and power >0.8. We conducted with the approval of the ethics committee of Aichi Saiseikai Rehabilitation Hospital (201,908). Results SG had muscle atrophy in all muscles compared to nSG (P < 0.05, power >0.8). SG had muscle weakness in all joint direction compared to nSG (P < 0.05, power >0.8). In particular, extension of knee joint and planter flexion of ankle joint muscle weakness, quadriceps femoris and triceps surae muscle atrophy occurred (P < 0.01, power >0.8). Conclusions Assessment and intervention of skeletal muscle in stroke sarcopenia patients should focus on the knee joint and ankle joint. Funding Sources The authors declare no conflicts of interest associated with this manuscript.

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The Effects of Ankle Joint Mobilization on Dorsiflexion Range and Gait Parameters in Chronic Stroke Survivors: A Systematic Review and Meta-analysis

Journal of Stroke Medicine ◽

10.1177/2516608520982874 ◽

2021 ◽

pp. 251660852098287

Author(s):

Hariharasudhan Ravichandran ◽

Balamurugan Janakiraman

Keyword(s):

Ankle Joint ◽

Meta Analysis ◽

Step Length ◽

Chronic Stroke ◽

Gait Velocity ◽

Stroke Survivors ◽

Timed Up And Go ◽

Unaffected Side ◽

Joint Mobilization ◽

Gait Parameters

Background: Ankle dorsiflexion movement restriction is a common presentation in most of the chronic stroke survivors. Spasticity and connective tissue changes around ankle, limits dorsiflexion, and interferes with balance and gait performances. Improving functional range of dorsiflexion is essential in post-stroke rehabilitation. Objectives: This meta-analysis analyzed the effects of ankle mobilization techniques in improving dorsiflexion range and gait parameters among chronic stroke survivors. Method: Articles published up to July 2020 were searched in CINAHL, PubMed, Embase, PsyINFO, and OpenGrey. English version of randomized controlled trials (RCTs) assessing the effects of ankle joint mobilization among chronic stroke subjects, with dorsiflexion range of motion (ROM) and gait parameters as outcome, were included. Characteristics of participants, interventions, outcome measure, and measures of variability were extracted. Methodological quality of included trials was assessed using PEDro scale and Cochrane Collaboration tool for the risk of bias. Pooled standardized mean difference was calculated using random effects model for dorsiflexion ROM, gait velocity, step length, cadence, and timed up and go (TUG). Results: Eight RCTs including 226 stroke patients, with mean methodological score of 6 out of 10 in PEDro, were eligible for this meta-analysis. Ankle joint mobilization demonstrated statistically significant improvement on passive dorsiflexion ROM, gait velocity, step length (affected side), and cadence outcomes. Nonsignificance was found in step length (unaffected side) and in TUG. Conclusion: The ankle mobilization techniques are effective in improving passive dorsiflexion ROM, gait velocity, and cadence in chronic stroke survivors. However, the retention effect of ankle mobilization among stroke subjects is not known.

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Voluntary activation failure contributes more to plantar flexor weakness than antagonist coactivation and muscle atrophy in chronic stroke survivors

Journal of Applied Physiology ◽

10.1152/japplphysiol.00804.2009 ◽

2010 ◽

Vol 109 (5) ◽

pp. 1337-1346 ◽

Cited By ~ 53

Author(s):

Cliff S. Klein ◽

Dina Brooks ◽

Denyse Richardson ◽

William E. McIlroy ◽

Mark T. Bayley

Keyword(s):

Muscle Atrophy ◽

Muscle Activation ◽

Voluntary Contraction ◽

Chronic Stroke ◽

Voluntary Activation ◽

Stroke Survivors ◽

Plantar Flexor ◽

Plantar Flexors ◽

Emg Amplitude ◽

Magnetic Resonance Imaging Mri

The contributions of nervous system muscle activation and muscle atrophy to poststroke weakness have not been evaluated together in the same subject. Maximal voluntary contraction (MVC) torque, voluntary activation (twitch interpolation), and electromyographic (EMG) amplitude were determined bilaterally in the plantar flexors of seven chronic stroke survivors (40–63 yr, 24–51 mo poststroke). Volumes of the plantar flexor muscles were determined bilaterally with magnetic resonance imaging (MRI). The mean (±SD) contralesional (paretic) MVC torque was less than one-half of the ipsilesional leg: 56.7 ± 57.4 vs. 147 ± 35.7 Nm ( P = 0.006). Contralesional voluntary activation was only 48 ± 36.9%, but was near complete in the ipsilesional leg, 97 ± 1.9% ( P = 0.01). The contralesional MVC EMG amplitude (normalized to the maximum M-wave peak-to-peak amplitude) of the gastrocnemii and soleus were 36.0 ± 28.5 and 36.0 ± 31.0% of the ipsilesional leg. Tibialis anterior (TA) EMG coactivation was not different between the contralesional (23.2 ± 24.0% of TA MVC EMG) and ipsilesional side (12.3 ± 5.7%) ( P = 0.24). However, TA EMG coactivation was excessive (71%) in one subject and accounted for ∼8% of her weakness based on the estimated antagonist torque. Relative (%ipsilesional leg) plantar flexor and gastrocnemii volumes were 88 ± 6% ( P = 0.004) and 76 ± 15% ( P = 0.01), respectively. Interlimb volume differences of the soleus, deep plantar flexors, and peronei were not significant. Preferred walking speed (0.83 ± 0.33 m/s) was related to the contralesional MVC torque ( r2 = 0.57, P = 0.05, N = 7), but the two subjects with the greatest weakness walked faster than three others. Our findings suggest that plantar flexor weakness in mobile chronic stroke survivors reflects mostly voluntary activation failure, with smaller contributions from antagonist activity and atrophy.

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