Despite their importance to a wide range of athletic and sporting activities, the hip flexors are the most neglected major muscle group in strength training. It is very rare to find training programs that include hip flexor exercises. By contrast there is usually a great deal of emphasis on exercises for the leg extensors.

There are some obvious reasons for this comparative neglect. The principal muscles involved in hip flexion are the psoas and the iliacus, collectively known as the iliopsoas. Because they are relatively deep-seated rather than surface muscles they may have been overlooked by bodybuilders who have traditionally been the major innovators in strength training. Secondly, there are no obvious ways to adequately exercise them with free weights. Finally, these muscles do not have the obvious functional importance of their extensor counterparts. Yet, as antagonists, both hip and knee flexors perform a vital role in controlling the rate of descent and ascent in leg extension exercises such as the squat