Correlation between rotational moments of the knee and other joints during gait, including the free moment of patients with a medial meniscus tear.

PURPOSE: Rotation of the knee puts stress on the medial meniscus and can be a factor in the progression of knee osteoarthritis. This study aimed to investigate the rotational moment (internal rotation and external rotation) of the knee during gait and relationship between the rotational moments of the knee and other joints, including the free moment during gait. METHODS: We included 18 patients with medial meniscus tears (MM group) and 10 asymptomatic participants in this study. We performed 3D gait analysis. The internal ankle, knee, and hip rotational moments as well as free moment were compared between the groups. Additionally, we investigated correlations between rotational moments of the knee and other joints during gait. RESULTS: The maximal knee external rotation moment in the MM group was smaller than that in the asymptomatic group ( p = 0.04, g = 0.76); however, there were no significant differences in the maximal internal rotation moment between the groups ( p = 0.97, g = 0.02). The internal rotation (external knee external rotation) moment positively correlated with the hip internal rotation moment ( p 〈 0.01, r = 0.69) in the MM group. CONCLUSIONS: The internal rotation (passive knee external rotation moment) did not decrease sufficiently, and correlation was observed between moments of the knee and hip in the MM group, especially during the late stance phase of gait. Reducing these abnormal moments during gait through rehabilitation may be important in patients with medial meniscus tears to prevent rapid progression of knee osteoarthritis.

Coordination Pattern of the Thigh, Pelvic, and Lumbar Movements during the Gait of Patients with Hip Osteoarthritis.

There are limited reports on segment movement and their coordination pattern during gait in patients with hip osteoarthritis. To avoid the excessive stress toward the hip and relevant joints, it is important to investigate the coordination pattern between these segment movements, focusing on the time series data. This study aimed to quantify the coordination pattern of lumbar, pelvic, and thigh movements during gait in patients with hip osteoarthritis and in a control group. An inertial measurement unit was used to measure the lumbar, pelvic, and thigh angular velocities during gait of 11 patients with hip osteoarthritis and 11 controls. The vector coding technique was applied, and the coupling angle and the appearance rate of coordination pattern in each direction were calculated and compared with the control group. Compared with the control group, with respect to the lumbar/pelvic segment movements, the patients with hip osteoarthritis spent more rates in anti-phase and lower rates in in-phase lateral tilt movement. With respect to the pelvic/thigh segment movements, the patients with hip osteoarthritis spent more rates within the proximal- and in-phases for lateral tilt movement. Furthermore, patients with osteoarthritis spent lower rates in the distal-phase for anterior/posterior tilt and rotational movement. Patients with hip osteoarthritis could not move their pelvic and thigh segments separately, which indicates the stiffness of the hip joint. The rotational movement and lateral tilt movements, especially, were limited, which is known as Duchenne limp. To maintain the gait ability, it seems important to pay attention to these directional movements.