Kinematic Analysis of Sit-to-Stand Motion in Knee Osteoarthritis

[目的]本研究は,体幹および下肢の運動連鎖の観点から変形性膝関節症(膝OA)の発症・進行に関与する機能障害を明らかにするために,膝OA患者における椅子からの立ち上がり動作(STS)の運動学的分析を行った。[対象]膝OAと診断された女性17名の膝OA群と膝関節痛を有さない女性16名の対照群とした。[方法]課題動作は座面高が下腿長の高さの椅子からのSTSとした。3次元動作解析システムKinema Tracer(キッセイコムテック社製)を用いて各体節および下肢関節の角度を求めた。[結果]身体重心(COM)前方移動期における各体節の角速度の平均値には有意差が認められなかったが,COM上方移動期における膝関節伸展,足関節底屈の角速度平均値は対照群に比し,膝OA群が有意に小さかった。[結語]膝OA群のSTSにおいて,臀部離床後に体幹前傾で得られた速度を下肢に伝えることができず,適切な膝関節の関節運動および肢節のアライメント保持が難しくなっていることが示唆された。
[Purpose] The purpose of this study was to analyze the kinematics of sit-to-stand motion (STS) in subjects with knee osteoarthritis (knee OA) and to demonstrate the factor of impairment responsible for pathogenesis and progression of knee OA based on discussion from the standpoint of the kinetic chain of the thorax-pelvis-lower extremity. [Subjects] The subjects were 17 patients with knee OA and 16 age-matched asymptomatic controls. [Methods] Subjects performed STS from a chair with a seat adjusted to the height of the subject's lower leg. Kinematic data of the body segment and joint angles were collected using a motion analysis system (Kissei Comtec). [Results] There were no significant differences between joint angular velocity averages of the body segment in forward movement of center of mass (COM), but those of the knee and ankle in upward movement of COM were significantly smaller. [Conclusion] These results suggest that knee OA subjects can't transfer kinetic energy generated in trunk forward tilting to the lower extremity, making it difficult for them to keep appropriate knee movement and alignment.