EFFECTS OF SINGLE CROUCH WALKING GAITS ON FATIGUE DAMAGES OF LOWER EXTREMITY MAIN MUSCLES

Single crouch walking gait (SCWG) is one of the main walking gaits when one of the legs is injured. However, the research on movement biomechanical characteristics (MBC) of lower extremity in SCWG has not been reported. So, the aim of this study is to analyze kinematics and main muscle fatigue damages of lower extremity in SCWG. Gaits data were collected with functional assessment biomechanics (FAB) system which applies the real-time wireless gait phase detection system, the movement function relations of joints of lower extremity were obtained by fitting the collected data in normal walking gait (NWG) and SCWG with Fourier series, the fitted movement functions were input to 3D human musculoskeletal model as driving functions for human movement to analyze the differences of MBC between SCWG and NWG. Finally, the muscle contractions were used to evaluate muscle fatigue damage. Compared with NWG, the result shows that the movement range of the joint angles of lower extremity are reduced in SCWG, the change law of hip internal/external rotation angle (IERA) has a significant difference, and the change laws of other joint angles are similarly between SCWG and NWG. The muscle contractions of Gluteus maximum (GMAX) 2, Gluteus meddle (GMED) 1, GMED2, Iliacus (ILI), Rectus femoris (RFEM), Soleus (SOL), Gastrocnemius (GAS) and Vastus lateralis (VLAT) are significantly larger in SCWG than in NWG (except GlutMed2 which is about 20–40% and VLAT which is about 63.8–76.1% of gait cycle), namely, these muscles easily cause muscle damages in SCWG. The contraction change of Adductor magnus (AMAG) is dispersed, so AMAG is prone to muscle fatigue in SCWG. The study results will fill in the gaps in the MBC of lower extremity in SCWG and provide data for Rehabilitation Medical Technology (RMT) and development of rehabilitation equipment of lower extremity.