Hyperextension of the lower back could be caused by:

Hyperextension of the lower back can indeed be influenced by multiple factors, and in this case, all the provided sources can contribute to this condition.

Tight hip flexors are a common issue, especially for individuals who spend prolonged periods sitting. This tightness can tilt the pelvis anteriorly, increasing lumbar lordosis, which is a risk factor for hyperextension. When the pelvis tilts excessively forward, it can lead to an exaggerated curve in the lower back, thus promoting hyperextension.

Additionally, performing exercises like leg raises or leg lifts requires a certain degree of lumbar extension. If not performed with proper technique, these exercises can place excessive stress on the lower back, leading to hyperextension, especially if the core muscles are weak or not adequately engaged.

Hooking the feet while executing sit-ups or curl-ups is another contributor. When the feet are anchored, it can create resistance that encourages the lower back to arch excessively during the movement. This action can result in hyperextension, particularly if the individual uses momentum rather than controlled contraction.

Considering all the factors listed, it's clear that each one has a potential role in causing hyperextension of the lower back, leading to the conclusion that all the answers collectively are correct. Recognizing these connections is crucial for