井元 大介

OBJECTIVE: This study aimed to examine the dose-response relationship between time spent in gait training and gait independence in individuals with non-ambulatory subacute hemiparetic stroke in a rehabilitation ward. DESIGN: Retrospective cohort study. SETTING: A rehabilitation ward in Japan. PARTICIPANTS: Non-ambulatory individuals with subacute hemiparetic stroke who were admitted and discharged from the ward between January 2018 and December 2021. INTERVENTIONS: Gait training using orthoses, canes, robotic technology, or manual assistance by the therapist as needed. MAIN OUTCOME MEASURE: Functional Independence Measure walk (FIM-walk) score. RESULTS: In total, 326 individuals (mean age [standard deviation (SD)], 70.4 years [14.7]; men, 205) were included in the study. The cumulative rates of achieving gait independence (FIM-walk score ≥ 6), estimated by the Kaplan-Meier method with total gait training time during hospitalization as the time scale, were 50.6% (95% confidence interval [CI]: 45.3-56.2), 61.7% (95% CI: 56.4-66.9), 65.0% (95% CI: 59.9-70.2), and 65.9% (95% CI: 60.5-70.8), at 2,000, 4,000, 6,000, and 8,000 min, respectively. When participants were categorized according to the severity of lower limb motor impairment assessed by the Stroke Impairment Assessment Set motor function in lower extremity total score at admission, the cumulative rates of gait independence were significantly different among the four groups, with complete paralysis being the lowest, followed by severe, moderate, and mild paralysis (p<0.001). Stratifying by gait training time per day, the higher the gait training time per day, the higher the cumulative rate of achieving gait independence in complete and severe cases, and the lower rate in mild cases (p<0.001). CONCLUSIONS: A dose-response relationship with a plateau relationship was found between gait training time and achieving gait independence for non-ambulatory individuals with subacute hemiparetic stroke. The relationships differ by the degree of severity of lower limb motor impairment and by training intensity.

BACKGROUND: Robot-assisted gait training (RAGT) has proven effective in addressing gait disorders in patients with stroke. However, its efficacy in patients with acute stroke has not yet been demonstrated. This pilot study is designed to evaluate the following: (1) feasibility of conducting a randomized controlled trial on RAGT for enhancing gait postacute stroke and (2) to obtain preliminary estimates regarding the potential efficacy of RAGT for achieving gait independence during the acute phase. METHODS: We will conduct an assessor-blinded, single-center, randomized controlled pilot trial involving 32 patients with acute stroke who are unable to walk. Participants will be randomly assigned to either the RAGT or the conventional gait training (CGT) groups. Each participant will receive 180 min of daily rehabilitation, including 60 min dedicated to gait training. The RAGT group will receive 40 min of RAGT and 20 min of CGT, while the CGT group will engage in 60 min of CGT. Interventions will continue for up to 8 weeks, or until participants achieve gait independence, as indicated by a Functional Ambulation Category score of ≥ 3. Feasibility outcomes will include recruitment, enrollment, protocol adherence, and retention rates. The primary clinical outcome will be the incidence of achieving gait independence during the intervention period. Secondary clinical outcomes will include gait performance measures, assessments of physical function and activity, and intervention dose. Adverse events associated with RAGT and CGT will also be documented to evaluate the safety of both interventions. DISCUSSION: Implementing RAGT during the acute phase of stroke may facilitate earlier attainment of gait independence compared to CGT. We aim to provide valuable insights into the feasibility of the proposed study design and generate preliminary data on the potential effects of RAGT on gait independence in the acute phase of stroke, providing a framework for future larger-scale trials. TRIAL REGISTRATION: This clinical trial was registered with the Japan Clinical Trials Registry (jRCT) on 19 June 2023 (registration number: jRCTs042230040). The study protocol was initially registered as version 1.0 and has since undergone minor amendments-currently on version 4.0. This protocol was written based on the latest version (ver. 4.0) registered with jRCT.

OBJECTIVE: To define long-term changes in subjective symptoms among polio survivors in Japan. DESIGN: Prospective cohort study. PATIENTS: Sixty-five polio survivors. METHODS: Surveys were conducted on subjective symptoms including muscle weakness and limb atrophy during 2007 and 2021. The results of manual muscle tests of the upper and lower limbs on both sides during 2007 were summed and scored, and the side with lower scores was defined as the poor side. The participants were classified as younger or older groups based on the median age at the first survey (i.e., 58 years old) and the subjective symptoms were compared between the two groups. RESULTS: As a whole, muscle atrophy and weakness progressed in the lower and upper limbs while fatigue was reduced. Muscle weakness progressed especially in the lower limbs on the poor side in the younger group, and in the older group it progressed in the lower limbs on the good side and the upper limbs on the poor side. CONCLUSION: The timing of progressive muscle weakness differed between the upper and lower limbs of younger and older polio survivors.

BACKGROUND: Robot-assisted gait training (RAGT) is an effective method for treating gait disorders in individuals with stroke. However, no previous studies have demonstrated the effectiveness of RAGT in individuals with acute stroke. This study aimed to investigate the effects of RAGT initiation within 1 week after onset on degree of gait independence in individuals with hemiparetic stroke. METHODS: This retrospective cohort study used propensity-score matching. Individuals admitted to Fujita Health University Hospital after stroke onset and underwent RAGT between March 2017 and June 2023 were enrolled. Ninety-two individuals were eligible and grouped into the acute (≤ 7 days after the onset) and subacute groups (8-90 days after onset). RAGT was conducted using Welwalk, primarily comprising a knee-ankle-foot orthosis type robot worn on one paralyzed lower extremity, with training sessions lasting approximately 40 min/day, occurring 3-7 days/week. The primary outcome was the gait under supervision within 90 days of onset, which was compared between groups using the log-rank test. RESULTS: After propensity-score matching, 36 individuals were included in the analysis, including 18 each in the acute and subacute groups; the participant demographics were not significantly different between the groups. RAGT was initiated at a median of 6 and 25 days after onset in the acute and subacute groups, respectively. The Kaplan-Meier curves after the log-rank test showed a significantly higher percentage and shorter median days to achieve gait under supervision in the acute group than in the subacute group. The cumulative incidence of gait under supervision events at 90 days after onset was 82.2% and 55.6% in the acute and the subacute groups, respectively. Half of the individuals achieved gait under supervision within 49 days and 75 days in the acute and subacute groups, respectively (p = 0.038). No significant differences were observed in the dose of rehabilitation program and gait training per day from onset to achieving gait under supervision. CONCLUSION: Initiation of RAGT within 1 week after stroke onset in individuals with hemiparesis may reduce the number of days required to achieve gait under supervision and increase the percentage of gait under supervision.

INTRODUCTION: Gait robots have the potential to analyze gait characteristics during gait training using mounted sensors in addition to robotic assistance of the individual's movements. However, no systems have been proposed to analyze gait performance during robot-assisted gait training. Our newly developed gait robot," Welwalk WW-2000 (WW-2000)" is equipped with a gait analysis system to analyze abnormal gait patterns during robot-assisted gait training. We previously investigated the validity of the index values for the nine abnormal gait patterns. Here, we proposed new index values for four abnormal gait patterns, which are anterior trunk tilt, excessive trunk shifts over the affected side, excessive knee joint flexion, and swing difficulty; we investigated the criterion validity of the WW-2000 gait analysis system in healthy adults for these new index values. METHODS: Twelve healthy participants simulated four abnormal gait patterns manifested in individuals with hemiparetic stroke while wearing the robot. Each participant was instructed to perform 16 gait trials, with four grades of severity for each of the four abnormal gait patterns. Twenty strides were recorded for each gait trial using a gait analysis system in the WW-2000 and video cameras. Abnormal gait patterns were assessed using the two parameters: the index values calculated for each stride from the WW-2000 gait analysis system, and assessor's severity scores for each stride. The correlation of the index values between the two methods was evaluated using the Spearman rank correlation coefficient for each gait pattern in each participant. RESULTS: The median (minimum to maximum) values of Spearman rank correlation coefficient among the 12 participants between the index value calculated using the WW-2000 gait analysis system and the assessor's severity scores for anterior trunk tilt, excessive trunk shifts over the affected side, excessive knee joint flexion, and swing difficulty were 0.892 (0.749-0.969), 0.859 (0.439-0.923), 0.920 (0.738-0.969), and 0.681 (0.391-0.889), respectively. DISCUSSION: The WW-2000 gait analysis system captured four new abnormal gait patterns observed in individuals with hemiparetic stroke with high validity, in addition to nine previously validated abnormal gait patterns. Assessing abnormal gait patterns is important as improving them contributes to stroke rehabilitation. CLINICAL TRIAL REGISTRATION: https://jrct.niph.go.jp, identifier jRCT 042190109.