Ipsilateral lower limb motor performance and its association with gait after stroke

BACKGROUND AND PURPOSE

Motor deficits of the ipsilateral lower limb could occur after stroke and may be associated with walking performance. This study aimed to determine whether the accuracy and movement path of targeted movement in the ipsilateral lower limb would be impaired in the chronic stage of stroke and whether this impairment would contribution to gait.

METHODS

Twenty adults with chronic stroke and 20 age-matched controls went through Mini Mental Status Examination (MMSE), and a series of sensorimotor tests. The targeted movement tasks were to place the big toe ipsilateral to the lesion at an external visual target (EXT) or a proprioceptive target (PRO, contralateral big toe) with eyes open (EO) or closed (EC) in a seated position. A motion analysis system was used to obtain the data for the calculation of error distance, deviation from a straight path, and peak toe-height during the targeted movement tasks and gait velocity, step length, step width and step length symmetry of the lower limb ipsilateral to the brain lesion during walking.

RESULTS

The stroke group had significantly lower MMSE and poorer visual acuity on the ipsilateral side, but did not differ in age or other sensorimotor functions when compared to the controls. For the targeted movement performance, only the deviation in PRO-EC showed significant between-group differences (p = 0.02). Toe-height in both EXT-EO and in PRO-EO was a significant predictor of step length (R2 = 0.294, p = 0.026) and step length symmetry (R2 = 0.359, p = 0.014), respectively.

DISCUSSION AND CONCLUSIONS

The performance of ipsilateral lower limb targeted movement could be impaired after stroke and was associated with step length and its symmetry. The training of ipsilateral targeted movement with unseen proprioceptive target may be considered in stroke rehabilitation.

Reliability and validity of the trunk position sense and modified functional reach tests in individuals after stroke

The psychometric qualities of the proprioception and dynamic trunk control tests have rarely been studied in individuals after stroke.

OBJECTIVE

To investigate the reliability and validity of the Trunk Position Sense Test (TPS) and Modified Functional Reach Test (MFRT) in persons after stroke.

METHODS

Thirty-two participants were included. The TPS and MFRT were assessed by two physiotherapists during a first session. After resting, a second session was conducted. The intraclass correlation coefficient (ICC) was calculated to assess the test-retest (ICC3,k) and inter-rater reliability (ICC2,k). Pearson correlations coefficients were calculated between TPS/MFRT performances and clinical tests (trunk strength, Timed Up and Go and Balance Assessment in Sitting and Standing Positions - BASSP).

RESULTS

The TPS inter-rater reliability was good for vertical error (ICC = 0.75 [0.50-0.88]) while it was moderate for horizontal error (ICC = 0.48 [0.10-0.75]) as well as for test-retest reliability (0.39 ≤ ICC ≤ 0.59). As for the MFRT, inter-rater (0.76 ≤ ICC ≤ 0.90) and test-retest reliability (0.71 ≤ ICC ≤ 0.91) were good to excellent for anterior, paretic et non-paretic displacements. Horizontal errors for the TPS (-0.26 ≤ r ≤ -0.36) and anterior MFRT (0.38 ≤ r ≤ 0.64) values correlated moderately with trunk strength.

CONCLUSION

The MFRT is a reliable test for persons after stroke with trunk control impairments. The TPS does not appear to be relevant for post-stroke individuals. This can be explained by the fact that its procedure is not easily applied for individuals after stroke - who may have significant motor and cognitive impairments.

Impacts of Stroke on Muscle Perceptions and Relationships with the Motor and Functional Performance of the Lower Extremities

Stroke results in paretic limb disabilities, but few studies have investigated the impacts of stroke on muscle perception deficits in multiaxis movements and related functional changes. Therefore, this study aimed to investigate stroke-related changes in muscle perceptions using a multiaxis ankle haptic interface and analyze their relationships with various functions. Sixteen stroke patients and 22 healthy participants performed active reproduction tests in multiaxis movements involving the tibialis anterior (TA), extensor digitorum longus (EDL), peroneus longus, and flexor digitorum longus (FDL) of the ankle joint. The direction error (DE), absolute error (AE), and variable error (VE) were calculated. The lower extremity of Fugl-Meyer Assessment (FMA-LE), Barthel Index (BI), Postural Assessment Scale for Stroke Patients, Tinetti Performance-Oriented Mobility Assessment (POMA), and 10-m walk test (10MWT) were evaluated. VE of EDL for the paretic ankle was significantly lower than that for the nonparetic ankle (p = 0.009). AE of TA, EDL, and FDL and VE of EDL and FDL of muscle perceptions were significantly lower in healthy participants than in stroke patients (p < 0.05 for both). DE of TA for the paretic ankle was moderately correlated with FMA-LE (r = -0.509) and POMA (r = -0.619) scores. AE and VE of EDL for the paretic ankle were moderately correlated with the 10MWT score (r = 0.515 vs. 0.557). AE of FDL for the paretic ankle was also moderately correlated with BI (r = -0.562). This study indicated poorer accuracy and consistency in muscle perception for paretic ankles, which correlated with lower limb functions of stroke patients.

The efficiency of mirror therapy on drop foot in Multiple Sclerosis Patients

INTRODUCTION

Although the effectiveness of mirror therapy (MT) has been proved in stroke persons, there is no scientific evidence about the results in people with multiple sclerosis. The aim was to investigate whether adding MT to exercise training and neuromuscular electrical stimulation (NMES) has any effect on clinical measurements, mobility, and functionality in people with multiple sclerosis (MS).

METHODS

Ambulatory people with MS, with unilateral drop foot, were included. MT group (n = 13) applied bilateral ankle exercise program with mirror following NMES for 3 days a week at hospital and exercise program for 2 days a week at home. Control group (n = 13) performed same treatment without mirror box (6 weeks). The later 6 weeks both groups performed only exercise program. Clinical measurements included proprioception, muscle tone of plantar flexor muscles (MAS), muscle strength of dorsiflexor, ankle angular velocity, and range of motion (ROM) of ankle. Functionality (Functional Independence Measurement-FIM), mobility (Rivermead Mobility Index-RMI), ambulation (Functional Ambulation Scale-FAS), duration of stair climb test, and 25-foot walking velocity were assessed at the beginning, in 6th and 12th weeks.

RESULTS

More positive improvements were obtained in MT group than control group in terms of range of motion (0.012), muscle strength (0.008), proprioception (0.001), 25 feet walking duration (0.015), step test duration (0.001), FAS (0.005), RMI (0.001), and FIM (0.001) after 6 weeks treatment. It was seen that this improvement maintained to 12th week on all clinical and functional measurements (p < .05).

CONCLUSION

The trial revealed that adding MT to exercise training and NMES has more beneficial effects on clinical measurements, mobility, and functionality in people with multiple sclerosis with unilateral drop foot.

Effect of Light Finger Touch, a Cognitive Task, and Vision on Standing Balance in Stroke

The aim of the exploratory study was to investigate the individual and combined effects of light finger touch, a cognitive task, and vision on postural sway in individuals with stroke. Nine older adults with stroke stood on the force platform with eyes open and eyes closed, with and without a light finger touch contact with the stationary frame, and when counting backward from a randomly chosen three-digit number or without it. The center of pressure (COP) excursion, velocity, range and sway area was calculated. Participants demonstrated significantly larger postural sway when vision was not available (p < 0.05), smaller postural sway when using a finger touch contact (p < 0.05), and increased postural sway while performing the cognitive task (p < 0.05). When finger touch and a cognitive task was performed simultaneously, body sway decreased as compared to standing and performing a cognitive task in eyes open (p < 0.05) and eyes closed conditions. Results indicate that light touch in individuals with stroke mitigates the impact of cognitive load. The findings contribute to the understanding of the role of sensory integration in balance control of individuals with neurological impairments and older adults.

Time-course investigation of postural sway variability: Does anxiety exacerbate the sensory reweighting impairment in chronic stroke survivors?

Although anxiety is one of the most prevalent psychological disorders in stroke survivors, its effect on sensory reweighting has not yet been fully studied. The aim of this work was to investigate how anticipation of collision avoidance events affects sensory reweighting in chronic stroke survivors with low and high levels of anxiety (LA-stroke and HA-stroke, respectively), as compared with healthy controls (HC), under the condition of perturbed proprioception. Eighteen LA-stroke and 18 HA-stroke survivors, as well as 18 gender- and age-matched HC, participated in this study. Postural sway variability (i.e. Root Mean Square (RMS) of the COP velocity) was measured for a duration of 180 s under two conditions: quiet standing and standing while predicting random virtual spheres to be avoided. Proprioceptive perturbation was simulated using bilateral Achilles tendon vibration at mid duration (60 s) for both conditions. The results showed that the HC were able to timely use visual anticipation to reduce the postural sway variability induced by tendon vibration. However, marked delay in using such anticipation was observed in stroke participants, especially in the HA-stroke group, as indicated by a significant decrease in the RMS of the COP velocity late in the vibration phase. This is the first study to consider the effect of anxiety while comparing sensory reweighting between stroke and healthy participants. The results indicated that chronic stroke survivors, particularly those with HA, could not efficiently use sensory reweighting to maintain balance in sensory conflicting conditions, which may subject them to loosing balance and/or falling. These findings are critical for future assessment and planning of rehabilitation interventions and balance in chronic stroke survivors.

Assessing lower limb position sense in stroke using the gradient discrimination test (GradDT™) and step-height discrimination test (StepDT™): a reliability and validity study

Purpose: To evaluate the psychometric properties of two novel tests of lower limb position sense.Methods: Our newly developed tests assess the discrimination thresholds of under-foot slope and step height perception using a two alternative forced choice approach. Stroke participants (n = 32) and age matched controls (n = 32) were tested. Inter- and intra-rater reliability and agreement, sensitivity and specificity, discriminant and convergent validity were evaluated.Results: Intra-rater reliability for both variants of the gradient discrimination test was excellent; intraclass correlation coefficients (ICC) =0.91 and 0.89. The step height discrimination test had excellent intra-rater reliability and agreement: ICC =0.95. Inter-rater reliability was also excellent in both tests (ICC= 0.85-0.93). Discriminant validity was demonstrated with significant differences in test performance between stroke and control participants (p < 0.001). Our novel tests did not significantly correlate with the proprioceptive component of the Erasmus modified Nottingham Sensory Assessment. Receiver Operating Characteristic curve analysis indicated both novel tests to have greater sensitivity and specificity than the proprioceptive component of the Erasmus modified Nottingham Sensory Assessment in predicting the presence of self-reported sensory impairments. Functional reach test, 10 meter walk test, centre of pressure measurement and reported falls showed significant and moderate to strong correlations with novel test performance (r = 0.40-0.60); the Erasmus modified Nottingham Sensory Assessment did not.Conclusions: Our novel, functionally oriented tests of lower limb position sense are reliable, valid and feasible for use in an ambulatory chronic stroke and elderly population.Implications for rehabilitationThe GradDT™ and StepDT are two novel tests of lower limb position sense which are reliable and valid in a chronic stroke sample.They offer clinicians and researchers sensitive, accurate and clinically usable measures of lower limb position sense.

Cryotherapy Reduces Muscle Spasticity But Does Not Affect Proprioception in Ischemic Stroke: A Randomized Sham-Controlled Crossover Study

OBJECTIVE

The aim of the study was to evaluate the immediate effects of cryotherapy (using an ice pack) on ankle joint position sense and the degree of spasticity after chronic hemiparetic stroke.

DESIGN

We used a sham-controlled crossover design. Sixteen chronic hemiparetic patients were randomly assigned to two groups: (1) those who received cryotherapy followed by a control intervention 15 days later (cryotherapy group) and (2) those who received the control intervention followed by cryotherapy 15 days later (control intervention group). Ankle joint position sense was measured on the paretic side using a Biodex Multi-joint System 3 dynamometer before and after 20 mins of either application on the calf muscles. Lower absolute error scores were calculated for data analyses and were used to determine joint position sense. The degree of spasticity of the plantar flexor muscles was scored according to the Modified Ashworth Scale.

RESULTS

Sixteen patients completed the crossover experiment; however, data analysis was successfully conducted in 15 participants. Cryotherapy reduced the degree of spasticity of the plantar flexor muscles without altering ankle joint position sense.

CONCLUSIONS

Cryotherapy (using an ice pack) may reduce plantar flexor spasticity without influencing proprioception.

The prevalence, distribution, and functional importance of lower limb somatosensory impairments in chronic stroke survivors: a cross sectional observational study

Purpose: To investigate the prevalence and distribution of lower limb somatosensory impairments in community dwelling chronic stroke survivors and examine the association between somatosensory impairments and walking, balance, and falls. Methods: Using a cross sectional observational design, measures of somatosensation (Erasmus MC modifications to the (revised) Nottingham Sensory Assessment), walking ability (10 m walk test, Walking Impact Scale, Timed "Get up and go"), balance (Functional Reach Test and Centre of Force velocity), and falls (reported incidence and Falls Efficacy Scale-International), were obtained. Results: Complete somatosensory data was obtained for 163 ambulatory chronic stroke survivors with a mean (SD) age 67(12) years and mean (SD) time since stroke 29 (46) months. Overall, 56% (n = 92/163) were impaired in the most affected lower limb in one or more sensory modality; 18% (n = 30/163) had impairment of exteroceptive sensation (light touch, pressure, and pin-prick), 55% (n = 90/163) had impairment of sharp-blunt discrimination, and 19% (n = 31/163) proprioceptive impairment. Distal regions of toes and foot were more frequently impaired than proximal regions (shin and thigh). Distal proprioception was significantly correlated with falls incidence (r = 0.25; p < 0.01), and centre of force velocity (r = 0.22, p < 0.01). The Walking Impact Scale was the only variable that significantly contributed to a predictive model of falls accounting for 15-20% of the variance. Conclusion: Lower limb somatosensory impairments are present in the majority of chronic stroke survivors and differ widely across modalities. Deficits of foot and ankle proprioception are most strongly associated with, but not predictive, of reported falls. The relative contribution of lower limb somatosensory impairments to mobility in chronic stroke survivors appears limited. Further investigation, particularly with regard to community mobility and falls, is warranted. Implications for Rehabilitation Somatosensory impairments in the lower limb were present in approximately half of this cohort of chronic stroke survivors. Tactile discrimination is commonly impaired; clinicians should include an assessment of discriminative ability. Deficits of foot and ankle proprioception are most strongly associated with reported falls. Understanding post-stroke lower limb somatosensory impairments may help inform therapeutic strategies that aim to maximise long-term participation, minimise disability, and reduce falls.

Elastic Tape Improved Shoulder Joint Position Sense in Chronic Hemiparetic Subjects: A Randomized Sham-Controlled Crossover Study

Background

Elastic tape has been widely used in clinical practice in order to improve upper limb (UL) sensibility. However, there is little evidence that supports this type of intervention in stroke patients.

Objective

To verify the effect of elastic tape, applied to the paretic shoulder, on joint position sense (JPS) during abduction and flexion in subjects with chronic hemiparesis compared to sham tape (non-elastic tape). Furthermore, to verify if this potential effect is correlated to shoulder subluxation measurements and sensorimotor impairment.

Methods

A crossover and sham-controlled study was conducted with post-stroke patients who were randomly allocated into two groups: 1) those who received Sham Tape (ST) first and after one month they received Elastic Tape (ET); 2) those who received Elastic Tape (ET) first and after one month they received Sham Tape (ST). The JPS was evaluated using a dynamometer. The absolute error for shoulder abduction and flexion at 30° and 60° was calculated. Sensorimotor impairment was determined by Fugl-Meyer, and shoulder subluxation was measured using a caliper.

Results

Thirteen hemiparetic subjects (average time since stroke 75.23 months) participated in the study. At baseline (before interventions), the groups were not different for abduction at 30° (p = 0.805; p = 0.951), and 60° (p = 0.509; p = 0.799), or flexion at 30° (p = 0.872; p = 0.897) and 60° (p = 0.853; p = 0.970). For the ET group, differences between pre and post-elastic tape for abduction at 30° (p<0.010) and 60° (p<0.010), and flexion at 30° p<0.010) and 60° (p<0.010) were observed. For the ST group, differences were also observed between pre and post-elastic tape for abduction at 30° (p<0.010) and 60° (p<0.010), and flexion at 30° (p<0.010,) and 60° (p<0.010). Potential effects were only correlated with shoulder subluxation during abduction at 30° (p = 0.001, r = -0.92) and 60° (p = 0.020, r = -0.75).

Conclusion

Elastic tape improved shoulder JPS of subjects with chronic hemiparesis regardless of the level of UL sensorimotor impairment. However, this improvement was influenced by the subluxation degree at abduction.

Joint position sense is bilaterally reduced for shoulder abduction and flexion in chronic hemiparetic individuals

BACKGROUND

The stroke is the leading cause of adult disability in the world. One of the main complaints of individuals post-stroke refers to the loss of function of the upper limb, as evidenced during the performance of activities of daily living. This difficulty may be related to an important component of sensorimotor control, joint position sense, a submodality of proprioception.

OBJECTIVES

To investigate whether the proprioception of both shoulders of chronic hemiparetic patients is altered during abduction and flexion.

METHODS

Thirteen subjects with chronic hemiparesis due to ischemic stroke and 13 healthy subjects matched for gender and age was included. The joint sense position was assessed using a dynamometer. Absolute error for shoulder abduction and flexion at the 30 and 60° was calculated.

RESULTS

No difference was found between the paretic and non-paretic limbs in movements at both 30 and 60°. Higher values of absolute error for both paretic and non-paretic limbs compared to the control were observed during abduction at 30 and at 60°.

CONCLUSIONS

Chronic ischemic post-stroke patients have bilateral proprioceptive deficits in the shoulder during abduction and flexion. But these deficits are dependent on the movement performed and the angle tested. The results demonstrate the need to include bilateral exercises and/or visual feedback in the rehabilitation program.