Which postural deviation is associated with sacral S1-S2?

Which postural deviation is associated with sacral S1-S2?

• A. Trendelenburg
• B. Kyphosis
• C. Forward head posture
• D. Scoliosis

Answer: (A)

Focus on what keeps the pelvis level during single-leg stance. The hip abductors, especially the gluteus medius, stabilize the pelvis and are supplied by nerves in the sacral region. When S1–S2 function is affected, these muscles weaken, so the pelvis drops toward the opposite side as you balance on one leg. That falling pelvis is the hallmark of the Trendelenburg posture, reflecting weakness of the hip abductors due to sacral nerve involvement. The other postures—kyphosis (excessive upper back curvature), forward head posture (neck alignment), and scoliosis (lateral spine curvature)—don’t directly relate to sacral nerve control of the hip abductors, so they don’t explain this scenario.

Focus on what keeps the pelvis level during single-leg stance. The hip abductors, especially the gluteus medius, stabilize the pelvis and are supplied by nerves in the sacral region. When S1–S2 function is affected, these muscles weaken, so the pelvis drops toward the opposite side as you balance on one leg. That falling pelvis is the hallmark of the Trendelenburg posture, reflecting weakness of the hip abductors due to sacral nerve involvement. The other postures—kyphosis (excessive upper back curvature), forward head posture (neck alignment), and scoliosis (lateral spine curvature)—don’t directly relate to sacral nerve control of the hip abductors, so they don’t explain this scenario.