What anatomical cause can lead to forward flexion deviation?

In the context of gait mechanics, forward flexion deviation occurs when the trunk leans forward during standing or gait, often resulting from an inability to extend the hips properly. A key anatomical cause leading to this deviation is a hip flexion contracture. This condition occurs when the hip flexor muscles (such as the iliopsoas) are tight or shortened, limiting the ability of the hip to extend fully.

When the hip cannot extend, compensatory strategies occur, commonly leading to a forward trunk lean as the body attempts to maintain balance and forward momentum. This forward lean can significantly impact a person's gait and functional mobility, as it alters the distribution of forces across the lower extremities.

On the other hand, weak quadriceps may impact knee stability and stance phase gait mechanics, but they do not directly produce the forward trunk flexion observed in this condition. The quadriceps primarily play a role in knee extension and stability. Weak abductors influence side-to-side stability rather than forward trunk positioning. Knee instability, while impactful, tends to produce different compensatory strategies, primarily affecting the knee joint mechanics rather than directly leading to a forward flexion deviation.

Therefore, the most relevant anatomical cause for forward flexion deviation is indeed a hip flexion contract