Objectives: The purpose of this study was to compare the interlimb biomechanical differences in patients who had undergone anterior cruciate ligament reconstruction (ACLR) in either dominant (ACLR-D) or nondominant (ACLR-ND) limbs and healthy controls (CON) during drop vertical jump (DVJ) task. To investigate whether the dominant or nondominant limb influences the risk of re-injury in ACLR patients.Methods: Thirty-three ACLR patients were divided into ACLR-D and ACLR-ND groups according to whether the surgical limb was dominant or nondominant. Seventeen healthy individuals were selected as the CON group. Three-dimensional kinematic data, ground reaction force (GRF) data, and surface electromyographic (EMG) data from the bilateral lower limbs of all participants were collected during the DVJ task. Two-way repeated-measures ANOVAs (limb × group) were performed on the variables of interest to examine the main effects of limb (dominant vs. nondominant) and group (ACLR-D, ACLR-ND, and CON), as well as the interaction between limb and group.Results: The nonsurgical limbs of ACLR group had significantly greater knee valgus angles, knee extension and valgus moments, peak posterior GRF (PPGRF), and peak vertical GRF (PVGRF) compared to the surgical limbs. The nonsurgical limbs of ACLR-ND patients demonstrated significantly greater knee extension and valgus moments, greater PPGRF and PVGRF, and reduced muscle activity in the vastus medialis and vastus lateralis compared to the CON group. The ACLR patients had reduced muscle activity in the quadriceps of the surgical limb and the hamstrings of the bilateral limbs compared to controls.Conclusion: The nonsurgical limbs of ACLR patients may suffer an increased risk of ACL injury due to altered landing mechanics and neuromuscular control strategies compared to the surgical limbs. Additionally, limb dominance influences movement patterns and neuromuscular control during DVJ task, the nonsurgical limbs of the ACLR-ND might be at higher risk of ACL injury compared to the ACLR-D group.

To investigate the effects of cognitive and motor dual tasks on gait characteristics and dynamic stability in older adults with sarcopenia compared with he

This study aims to examine the effects of various static standing postures on knee biomechanics during dynamic activities, including walking, running, and jumping. Twenty healthy participants (10 males and 10 females; age: 24.7 ± 1.3 years; height: 1.73 ± 0.08 m; weight: 66.5 ± 10.7 kg) performed three distinct static calibration trials: (1) 30° toe-in, (2) 0° neutral posture, and (3) 30° toe-out, before walking, running, and jumping at self-selected speeds. The primary outcome measures included knee joint angles and moments in the sagittal (flexion/extension), frontal (adduction/abduction), and transverse (internal/external rotation) planes. Repeated-measures ANOVA with statistical parametric mapping (SPM) was conducted to evaluate differences across static calibration posture trials. Compared to the neutral (0°) posture, the 30° toe-in posture significantly increased knee adduction angle, external rotation angle, and adduction moment, while reducing knee flexion angle and extension moment during walking, running, and jumping. Conversely, the 30° toe-out posture increased knee abduction angle and internal rotation angle, while decreasing knee adduction moment, relative to the neutral posture. When comparing the toe-out to toe-in postures, the toe-out posture yielded greater knee flexion, abduction, and internal rotation angles, but a reduced adduction moment across all tasks. Static calibration postures significantly affect knee biomechanics, highlighting the necessity for standardized positioning in clinical assessments to prevent obscuring or amplifying clinical outcomes.

Background: Patellofemoral pain syndrome (PFPS) is a common causative factor of knee pain. Exercise and electrical muscle stimulation (EMS) have been shown to improve knee function and relieve pain in patients with PFPS. However, the effect of exercise and EMS training on lower limb mechanics is unclear. The purpose of this study was to investigate the lower limb mechanics during single-leg squats following 6-week training interventions of exercise and EMS. Methods: 46 participants were recruited and randomly assigned into the muscle strength training (MST) group (21.5±3.8 yr, 174.7±8.4 cm, 69.5±11.7 kg) and combining EMS with strength training (EMS) group (22.2±4.3 yr, 173.8±7.4 cm, 72.4±13.2 kg) from the local university. Lower limb mechanics during single-leg squats were collected at the baseline and following the 6-week intervention for each group by using infrared motion capture systems and force platform. Two-way (group by time) analysis of covariance tests with repeated measures were applied to analyze the data. Results: ANCOVA with repeated measures indicated that during single-leg squat, both groups showed significant decreases in peak patellofemoral joint stress (F=30.384, P < 0.001, η ²=0.459), peak patellofemoral joint stress force (F=25.063, P < 0.001, η ²=0.379), knee extension moment (F=13.603, P=0.001, η ²=0.264), knee abduction moment (F=5.086, P=0.030, η ²=0.113) and knee external rotation moment (F=4.277, P=0.045, η ²=0.099) over time, but the EMS group had a larger change in peak patellofemoral joint stress (F=5.910, P=0.020, η ²=0.138) over time compared to the MST group. Conclusions: EMS training is beneficial for altering lower limb movement patterns and joint loading during single-leg squats in patients with PFPS compared to MST.

Background/Purpose: Non-specific lower back pain (NLBP) is one of the most common causes of disability worldwide. In patients with NLBP, reduced lumbar flexion-relaxation and reduced variability of muscle activity distribution are reported as abnormal muscle activity. Muscle energy technique (MET) is used to be a conservative, non-pharmacological treatment method for somatic dysfunctions of the musculoskeletal system. However, the effect of MET approach on the flexion-relaxation phenomena (FRP) is unclear. Therefore, the purpose of this study was to investigate the effects of MET on pain, lumbar function, and FRP in patients with NLBP. Methods/Design: Thirty patients with NLBP were randomized into the MET group (21.9±2.0 yrs, 1.72±0.09 m, 67.3±14.0 kg) and control group (20.9±1.2 yrs., 1.73±0.09 m, 65.0±9.6 kg). They received MET intervention and health lecture series for 4-weeks, respectively. Pain scores (Visual Analogue Scale, VAS), the lumbar dysfunction index (Oswestry Disability Index, ODI), and FRR of the erector spinae (FRR-ES) and multifidus (FRR-M) during trunk flexion-relaxation tests were assessed before and after the intervention. Two-way analysis of variance tests with repeated measures was used to evaluate MET effects. Results: Significant interactions were detected in VAS (P=0.001, η ²=0.308) and ODI (P=0.005, η ²=0.244). The VAS (from 5.07±1.39 to 2.20±1.32, P < 0.001) and ODI (from 18.53±5.83 to 10.00±8.45, P < 0.001) were decreased at week 5 compared to week 0, respectively. Additionally, the VAS ( P < 0.001) and ODI (P < 0.001) were lower in the MET group compared to the control group at week 5, respectively. Similarly, significant interactions were detected in FRR-ES (P=0.009, η ²=0.244) and FRR-M (P=0.047, η ²=0.148). The FRR-M (from 11.72±5.73 to 14.79±6.52, P=0.028) was increased in the MET group, while the FRR-ES (from 17.30±4.19 to 14.92±4.47, P=0.009) was decreased in the control group at week 5 compared to week 0, respectively. No significant differences were detected for both FRR-ES (P=0.328) and FRR-M (P=0.864) between the MET group and the control group at week 5. Conclusion: MET could be recommended as one of the clinical treatments for NLBP to relieve pain and improve lumbar function.