Objective: Muscle fatigue contributes to anterior cruciate ligament (ACL) injuries, with increased knee and hip abduction observed during fatigue. However, there have been no reports revealing the differences between fatigue tasks or the duration of these changes. In this study, we conducted single-leg drop landings before and after hip and knee fatigue tasks to elucidate the changes in lower limb biomechanics over time. Methods: Twenty-two male participants performed single-leg drop landings before, immediately after, and 5, 10, and 15 min after fatigue tasks involving isokinetic hip abduction/adduction (hip fatigue task [HFT]) and knee extension/flexion (knee fatigue task [KFT]). Hip and knee kinematic and kinetic data were collected using a three-dimensional motion analysis device and two force plates. A two-way ANOVA was performed with both the fatigue task (HFT and KFT) and time point (Time 1 to Time 4) as factors, and the main effects and interactions were calculated. Results: The knee adduction angle after the HFT was significantly greater than that after KFT immediately following the fatigue task. The knee flexion moment was significantly lower in the KFT, whereas the knee adduction and internal rotation moments were significantly higher in the HFT immediately after the fatigue task. Conclusion: This study revealed distinct kinematic and kinetic changes specific to each fatigue task, particularly in the frontal plane for hip joint tasks and the sagittal plane for knee joint tasks. These findings could assist in the development of ACL injury prevention programs tailored to the functional improvement and exercise capacity of each joint.

Background: Manual resident handling is a major occupational health concern in long-term care settings. No-lifting care (NLC) aims to reduce physical burden by limiting manual lifting and promoting the appropriate use of assistive devices. This preliminary study examined changes in care workers’ health, work-related outcomes, and quality of life during a 1-year NLC implementation program at a geriatric health services facility. Methods: This single-facility pre–post study included 33 eligible care workers. Questionnaire surveys, including the WHOQOL-26, were conducted at baseline, 6 months, and 12 months (post-intervention follow-up). Valid responses were obtained from 25, 19, and 19 participants, respectively. Sixteen participants completed the WHOQOL-26 at all three time points and were included in the complete-case longitudinal analysis. WHOQOL-26 scores were analyzed using one-way repeated-measures analysis of variance or the Friedman test, as appropriate. Results: The frequency of physical discomfort, intention to leave, and perceived difficulty in providing care showed positive descriptive changes following NLC implementation. Among complete cases, psychological domain scores decreased from 17.0 ± 2.1 at baseline to 14.1 ± 2.8 at 6 months and increasing to 16.6 ± 2.8 in the post-intervention follow-up (p < 0.01). Environment domain scores showed a similar pattern, decreasing from 22.2 ± 3.7 to 14.1 ± 2.8 and subsequently increasing to 23.1 ± 3.5 (p < 0.01), respectively. Conclusions: NLC implementation support was associated with favorable descriptive changes in selected work-related outcomes. The temporary decline and subsequent recovery in psychological and environment domain scores may reflect an adjustment process during implementation. Our findings support the use of NLC as an organizational change requiring sustained practical and on-site support.