Final answer:
The term 'Altered reciprocal inhibition' is used to describe the scenario where an overactive muscle group reduces the neural drive to its antagonist, such as an overactive hip flexor complex inhibiting the hip extensor complex.
Step-by-step explanation:
The key term that best describes an overactive hip flexor complex decreasing neural drive to the hip extensor complex is a) Altered reciprocal inhibition. This term refers to a phenomenon where an overactive muscle (hip flexor complex) inhibits its functional antagonist (hip extensor complex) through the nervous system. This can result in a negative impact on the strength and function of the inhibited muscle (hip extensors), potentially leading to issues like poor posture, muscle imbalances, and an increased risk of injury.
Synergistic dominance occurs when a synergist takes over function for a weak or inhibited prime mover. Altered length-tension relationship refers to the relationship between the length of a muscle and the tension it produces at that length, with changes potentially leading to less than optimal muscle function. Lastly, reciprocal inhibition is a normal process that occurs when muscles on one side of a joint relax to accommodate contraction on the other side of that joint.