Hyuk-Jae Choi

Background/Objectives: Wearable powered gait orthoses are prescribed as assistive equipment, on the premise that torque at an impaired joint improves walking while the device is worn; the device also adds mass. Where a hip module and a knee–ankle–foot module can be worn together, the combined configuration places the mass of both on one limb, and whether its walking cost exceeds that of either module alone has not been tested under a common protocol. Methods: We analysed individual participant data from two previously published prospective studies, neither of which compared configurations. Forty-three adults with central neurological gait impairment, enrolled during 2024, were trained over six supervised sessions with a bilateral hip orthosis (HO, n = 13), a unilateral knee–ankle–foot orthosis (KAFO, n = 15), or both worn together (HKAFO, n = 15); the primary 6MWT analysis was performed on the complete-case subsample (n = 41, with HO n = 12, KAFO n = 14, HKAFO n = 15). The assisted–unassisted differential was computed per participant as (device-assisted − unassisted)/unassisted × 100; negative values indicate a shorter distance with the device. Results: No statistically significant baseline differences were detected across the three groups. The six-minute walk differential was larger for the HKAFO than for either single-region configuration at baseline (−24.9% versus −6.0% and −7.6%; Kruskal–Wallis p = 0.008) and after six sessions (−17.1% versus −5.9% and −4.3%; p = 0.012), whereas the two single-region configurations were indistinguishable at both assessments (p = 0.397 and 0.916). Short-distance gait speed did not differ between configurations (p = 0.290 and 0.457). Conclusions: The walking cost of the combined configuration was associated with a larger assisted–unassisted differential than that of either constituent module. We propose that this reflects the mass carried on a single limb rather than a shortfall in assistance, a reading these data support but cannot establish in the absence of kinematic or metabolic measurements. These findings should be regarded as hypothesis-generating and require prospective replication in a larger, adequately powered cohort.

Background: Wearable powered gait orthoses offer a clinically flexible alternative to treadmill-based robotic systems, yet evidence on different device configurations matched to the site of neuromuscular impairment remains limited. Methods: In this multicenter prospective pilot study, 75 participants with neurological gait impairment were allocated to a hip orthosis (HO; n = 39) or a knee–ankle–foot orthosis (KAFO; n = 36) group based on clinical assessment of predominant gait pattern. Both groups completed six overground gait-training sessions over three weeks. Primary outcomes were the Six-Minute Walk Test (6MWT) and Ten-Meter Walk Test (10MWT), assessed without (WO) and with (WITH) the device. Secondary outcomes were the Berg Balance Scale (BBS), Timed Up and Go Test (TUG), and Dynamic Gait Index (DGI), all assessed without the device. Wilcoxon signed-rank tests were used for pre-to-post comparisons. Results: Both groups demonstrated significant improvements in primary walking outcomes, with consistent gains in unassisted (WO) 6MWT and 10MWT performance across groups and in device-assisted (WITH) 10MWT speed; the one exception was a small statistically significant but clinically negligible decrease in device-assisted 6MWT in the KAFO group (−4.1 m, below established MCID). In the KAFO group, BBS improved by a median of 5.5 points (43.5 to 49.0, p = 0.0005), TUG decreased by 5.1 s (p < 0.001), and DGI improved by 6.0 points (p = 0.002); all three changes exceeded published minimum detectable change thresholds. In the HO group, pre-to-post differences in BBS (+1.0), TUG (+0.8 s; an unfavorable direction), and DGI (−2.0; an unfavorable direction) were statistically detectable but small in absolute magnitude, fell at or below published thresholds for minimum detectable change, and should not be interpreted as clinically meaningful improvement. The WO-WITH performance gap in the KAFO group narrowed substantially after training, with 10MWT time no longer differing significantly between conditions at post-training (p = 0.116). Conclusions: Six sessions of gait pattern-matched powered gait orthosis training produced clinically meaningful within-group improvements in walking outcomes in both groups. In the KAFO group, balance and functional mobility outcomes also showed clinically meaningful improvements; in the HO group, balance and functional mobility outcomes showed only statistically detectable but clinically non-meaningful fluctuations around near-ceiling baseline scores. Walking benefits generalized to unassisted ambulation in both groups. These findings support the feasibility of an individualized orthosis prescription framework and provide a basis for future randomized controlled trials.

This case study investigated the effects of a novel self-balancing robotic-assisted knee–ankle–foot orthosis (RA-KAFO) on gait function and reducing physical effort in a 52-year-old male with an incomplete lumbar 4–5 spinal cord injury (SCI). The participant underwent gait trials under three conditions: overground walking with crutches, RA-KAFO with crutches, and self-balancing RA-KAFO, across both comfortable and fast walking speeds. Results indicated significant improvements with the self-balancing RA-KAFO, including increased functional ambulation category (FAC) scores, reduced rate of perceived exertion (RPE), faster 10-m walk test velocities, and normalized knee joint kinematics. These findings demonstrate that the self-balancing RA-KAFO may offer superior gait stability and efficiency compared with conventional orthotic systems, highlighting its potential as an effective intervention in SCI rehabilitation.

While “passive” hip–knee–ankle–foot orthoses (HKAFOs) have been developed to enhance walking mobility for individuals with complete spinal cord injury, self-balancing robotic assisted hip–knee–ankle–foot orthoses (SRA-HKAFOs) have not been compared. The aim of this study was to compare therapeutic differences in kinematics and temporal–spatial parameters between “powered” HKAFOs and SRA-HKAFOs in individuals with complete spinal cord injury under both slow and fast walking conditions. A patient with a complete T11 spinal cord injury underwent the “powered” HKAFOs and SRA-HKAFOs under slow and fast walking conditions. Outcome measures included the functional ambulation category (FAC), perceived rate of exertion, walking speed, and hip and knee joint kinematics during a 10[ ]m walking test (10[ ]MWT). SRA-HKAFOs showed substantial improvements compared to “powered” HKAFOs in the FAC (from level 0 to 3), perceived rate of exertion, walking speed, and hip and knee joint kinematics during the 10[ ]MWT. The SRA-HKAFO system may provide promising clinical evidence as an alternative, powerful robotic gait-assisted vehicle to maximize independence in ambulation by enhancing hip and knee joint kinematics. The temporal–spatial gait parameters in patients with complete spinal cord injury were also improved.

Gait impairment is one of the most disabling consequences of stroke and substantially limits functional independence. While traditional orthoses provide joint stabilization, they often restrict natural motion and lack adaptive support. This study is aimed at evaluating the short‐term effects of an electric knee–ankle–foot orthosis (E‐KAFO) on gait performance and energy efficiency in patients with hemiplegia and at assessing how baseline balance ability, measured using the Berg Balance Scale (BBS), influences outcomes. This pre–post intervention, nonrandomized study enrolled poststroke survivors ( n = 22), who were stratified into high‐ (BBS > 45) and low‐ (BBS ≤ 45) balance groups (HBG and LBG, respectively). Participants underwent gait assessments under two conditions: body‐powered condition (BP_C), to evaluate rehabilitation effects independently of the device, and E‐KAFO_C, to assess short‐term assistive efficacy immediately after device use. All assessments were conducted before and after a 3‐week intervention comprising seven E‐KAFO training sessions. The primary outcome was gait speed, measured using the 5‐m walk test (5‐mWT). The 3‐min and 6‐min walk tests (3‐MWT and 6‐MWT) and the physiological cost index (PCI) were also evaluated to assess gait endurance and energy efficiency. The 5‐mWT and 3‐MWT/6‐MWT were performed in randomized order to minimize order‐related bias. No standard rehabilitation‐only control group was included. Assistive effects (E‐KAFO_C) and rehabilitative effects (BP_C) were analyzed and reported separately. Two‐way repeated measures analysis of variance was used to assess the effects of group, time, and their interaction. Significant improvements in gait speed and endurance were observed across both conditions, with the LBG showing greater relative gains postintervention. In the E‐KAFO_C condition, the LBG demonstrated a 33.31% increase in 5‐mWT speed and a 25.51% increase in 3‐MWT distance. Notably, PCI decreased in both groups, although the reduction was significant only in the LBG. These findings underscore the distinction between the short‐term assistive benefits of the E‐KAFO and the rehabilitative improvements captured by BP_C outcomes, emphasizing that BP_C results serve as the primary indicator of rehabilitation effectiveness. Importantly, baseline balance ability assessed by the BBS influenced assistive and rehabilitative responses, supporting its relevance for patient stratification. Given the exploratory design and limited sample size, these findings are hypothesis‐generating and require confirmation in larger randomized controlled trials. Trial Registration: WHO International Clinical Trials Registry Platform, supported by the Korea Disease Control and Prevention Agency (KDCA): KCT0011412