抄録
[Purpose] We investigated the change of the movement of the Center of the Gravity (COG) while walking in the recovery process after surgery. [Subjects] The subjects were 9 women who had undergone total hip arthroplasty (THA) and 11 healthy women as controls. [Methods] Kinetic analyses were conducted using force platforms and a three-dimensional motion analyzer. [Results] At 4 weeks postsurgery, gait velocity was slow, and showed an asymmetric and large COG displacement with dynamic properties requiring inefficient heavy work mainly undertaken by the non-operated lower extremity. The COG displacement width and the work done were significantly reduced during one gait cycle with increased gait velocity at postoperative 6 months, and bilateral symmetry for the work in the push-off period was enhanced. Although significant differences were no longer found in many parameters when compared with the control group, elongated time in double-limb support persisted, and the lateral displacement width of COG, displacement volume, and the total internal work done during one gait cycle showed somewhat low values. [Conclusion] These findings can be interpreted as a strategy to gain overall stability while compensating for the functional disturbance such as limited hip motion and decreased muscle strength around the hip joint by restraining the COG displacement.
