Biomechanical response of lower limb joints to lateral wedge insoles.

Lateral wedge insole (LWI) is a frequently recommended treatment option for early and midterm stages of medial knee osteoarthritis. However, studies of its effects on the lower limb joints are incomplete and imperfect. The main purpose of this study was to quantitatively analyze the response of intervention of LWI on lower-limb joint kinematics, ground reaction forces (GRFs), and centre of pressure (COP). Gait analysis of 16 healthy subjects was conducted. Three-dimensional motion data and force plate measurements were collected in the control (barefoot) and experimental conditions (wearing a pair of assigned shoes with 0, 7, and 10 mm LWIs). Results showed that the peak knee flexion angle was increased by 3.43°, 3.09°, and 3.27° with 0, 7, and 10 mm LWIs, respectively (p < 0.01). The ankle peak dorsiflexion angle was significantly decreased by 3.79°, 2.19°, and 1.66° with 0, 7, and 10 mm LWIs, respectively (p = 0.02). The internal rotation angle was increased by 2.78°, 3.76°, and 4.58° with 0, 7, and 10 mm LWIs, respectively (p < 0.01). The forefoot with LWIs showed highly significantly smaller inversion, eversion, and adduction angles (all p < 0.01). The 1st peak of the vertical GRF (p = 0.016) also increased significantly by a maximum of 0.06 body weight (BW) with LWIs. These results indicated that biomechanical changes and limitations of lateral wedges insole should be analyzed in more detail, possibly leading to new guidelines for the design and application.

The Kinematic and Kinetic Responses of the Trunk and Lower Extremity Joints during Walking with and without the Spinal Orthosis.

Spinal orthoses are an effective option for restoring the spine to its original position and controlling poor posture. However, the effects of poor posture and spinal orthoses on the kinematics and kinetics of trunk and lower extremity joints remain unclear. A six-camera Vicon motion capture system and two AMTI force plates were employed to collect gait parameters, including joint angle (spine, thorax, hip, knee, and ankle), range of motion (ROM), and ground reaction forces (GRFs). Furthermore, joint moments and joint reaction forces (JRFs) were calculated using a full-body musculoskeletal model in OpenSim. One-way repeated-measures ANOVA (p < 0.05) was used to compare significant differences among three trial conditions. These three conditions were walking in a normal posture, poor posture, and spinal orthosis. The results showed that spine ROM in the coronal and transverse plane was significantly lower when walking with a spinal orthosis compared to walking in normal and poor posture (p < 0.05). Compared to normal posture, the lumbar moments and back compressive forces were significantly increased when walking in poor posture (p < 0.05). However, when walking with a spinal orthosis, there was a significant decrease in trunk moments and reaction forces compared to walking in poor posture (p < 0.05). Individuals with poor posture could potentially induce instability and disorders, as evidenced by an increase in trunk moments and JRF compared to the normal posture. Spinal orthosis not only restricts spine ROM but also reduces the load on the spine and thus increases balance and stability.