Pathological Gait Lecture 8 PDF

Biomechanics I Dr. Noha Elserty Pathological gait Impaired gait in common Orthopedic conditions Gluteus Medius Weakness Gluteus medius weakness may occur as either a frank injury to the gluteus...

Biomechanics I Dr. Noha Elserty Pathological gait Impaired gait in common Orthopedic conditions Gluteus Medius Weakness Gluteus medius weakness may occur as either a frank injury to the gluteus medius or secondarily following an injury to another aspect of the limb. GRFV passes medially to hip joint and creates a strong adduction moment around hip joint so, there is tendency of pelvis and trunk to drop laterally to the opposite side toward non-stance limb and this action should be compensated by abductors muscles activity. so, the opposite hip and pelvis drops during this phase (LR, MST) if the gluteus medius has insufficient strength to hold the pelvis level. For example, if the right gluteus medius is weak, when the individual is in midstance on the right, the left hip and pelvis drops. This is a Trendelenburg gait. Compensation: an individual may compensate for a gluteus medius deficiency by lean the trunk laterally towards the ipsilateral side of weakness during midstance. 1 Biomechanics I Dr. Noha Elserty Moving the HAT directly over the limb reduces the moment arm of the gravitational force as it shifts the GRFV toward the affected side. So, the weak gluteus medius. is not required to exert as much force. If the GRFV passes via hip joint, no moment will be created. If it passes lateral to the joint, it will create abduction moment which will be compensated by activity in adductor moment. Unilateral weakness cause Trendelenburg gait, while bilateral weakness cause waddling gait. This type of gait on the long run cause scoliosis, back pain, and fatigue. 2