A posterior lean during ambulation is commonly observed with paralysis of which muscle group?

A posterior lean during ambulation is typically associated with paralysis or weakness of the hip extensors. The hip extensors, primarily the gluteus maximus, play a crucial role in stabilizing the pelvis and providing propulsion during the swing and stance phases of walking. When these muscles are weak or paralyzed, individuals often compensate by leaning their trunk backward to maintain balance and stability. This posterior lean helps to shift the center of gravity posteriorly, allowing for better control during ambulation despite the lack of effective hip extension.

Other muscle groups mentioned, such as the hip abductors, knee flexors, and ankle dorsiflexors, do not specifically align with the characteristic compensatory mechanism of posterior leaning. For instance, weakness in hip abductors would typically result in lateral pelvic tilt, knee flexors affect swinging movements, and ankle dorsiflexors are critical in controlling foot clearance and stability rather than causing a posterior lean. Understanding these muscle functions is key in recognizing gait deviations and planning appropriate interventions in rehabilitation contexts.