J Korean Acad Rehabil Med.  1997 Feb;21(1):160-172.

Dynamic Electromyography of Quadriceps Muscle and Kinematic Analysis in Stiff-Legged Gait

• Sung DH

Abstract

Patients who have had strokes or other central nervous system disorders, often walk with stiff legged gait on the affected site. We analyzed the gait of adult hemiparetic and paraparetic patients who were community ambula tors with stiff legged gait using a three dimensional motion analyzer and the dynamic electromyography. The purpose of the study is (1) to classify the dynamic EMG pattern of quadriceps muscle during preswing and swing-phase (2) to evaluate the characteristics of the kinematic motion curve of the knee in stiff legged gait. Dynamic EMG patterns of quadriceps muscle during preswing and midswing phase could be classified into four classes(Class I: rectus femoris and vastus medialis and vastus lateralis fire simultaneously, class II: rectus femoris and one of vasti fire simultaneously, class III: only rectus femoris fires, class IV: no abnormal firing of rectus femoris and vasti). All of paraparetic patients had sufficient hip flexor strength and the class III EMG pattern was the most frequently observed pattern in these patients. Hemiparetic patients showed diverse dynamic EMG patterns with a similar frequency (4 cases of class I 6 cases of class III, 5 cases of class IV). In the kinematic analysis, a dimpling on the motion curve of the knee during preswing and initial swing-phase was the most characteristic finding which reflected the blocking or delay of the knee flexion(smooth convexity which reflected the progressive increase of flexion disappeared). It was noted most frequently in paraparesis patients who had the class III EMG pattern. In hemiparesis patients who had poor hip flexor strength, there was no dimpling on the motion curve of the knee even though they showed the class III EMG pattern. Only half numbers of hemiparesis patients who had sufficient hip flexor strength with the class III EMG pattern showed a dimpling on the motion curve.

MeSH Terms

Adult
Central Nervous System Diseases
Electromyography*
Fires
Gait*
Hip
Humans
Knee
Leg
Paraparesis
Paresis
Quadriceps Muscle*
Stroke