In the context of low lumbar L4-L5, hip weakness and instability put the patient at risk for which condition?

• A. Hip flexion contractures and dislocation/subluxation
• B. Knee osteoarthritis
• C. Ankle inversion sprain
• D. Lumbar scoliosis

Answer: (A)

When the lower lumbar region is affected, the muscles around the hip become weak and the joint loses stable control. The hip joint depends on balanced, active muscle support to keep the femoral head centered in the acetabulum. With weakness and instability, the femoral head can drift and the soft tissues around the hip can tighten into a flexed position, leading to flexion contractures. Simultaneously, the lack of normal muscular stabilization increases the risk that the head of the femur moves out of the socket, causing dislocation or subluxation. This combination—tightening in flexion and a poorly centered joint—best explains why hip flexion contractures and dislocation/subluxation are the concern in this scenario.

Knee osteoarthritis, ankle sprains, and lumbar scoliosis are possible problems in various contexts, but they are not the most direct or immediate consequence of hip weakness and instability from a low lumbar lesion. The hip is the joint most directly affected in this setting, making hip contractures and dislocation/subluxation the most likely risk.