Lesson 13: Hip Flexors and Anterior Thigh Muscles

This course describes the hip flexors and anterior thigh muscles (quadriceps) including the psoas, iliacus, tensor fascia latae (TFL), rectus femoris, vastus medialis (VMO), vastus lateralis, and vastus intermedius. These muscles contribute to motion of the femur at the hip joint (acetabulofemoral joint) and the knee joint (tibiofemoral joint). Examples include the psoas, iliacus, tensor fascia latae, and rectus femoris contributing to hip flexion during a leg raise or being lengthened during a hip flexor stretch, and the rectus femoris, vastus medialis (VMO), vastus lateralis, and vastus intermedius contributing to knee extension during squats, lunges, and a leg press. Note, these muscles also play a role in maintaining optimal posture and optimal arthrokinematics of the hip joint, knee joint, and lumbar spine. Sports medicine professionals (personal trainers, fitness instructors, physical therapists, massage therapists, chiropractors, occupational therapists, athletic trainers, etc.) must be aware of these muscles for the analysis of human movement, and the development of sophisticated exercise programs and therapeutic (rehabilitation) interventions. Further, this course is essential knowledge for future courses discussing detailed anatomy like neural innervations of the hip flexor musculature (e.g. femoral nerve), the synergistic function of these muscles with other hip muscles (e.g. psoas and iliacus contributing to external rotation with the piriformis and deep rotators of the hip), injury (e.g. hip pain, groin pain, hip flexor pain, hip flexor weakness, hip flexor rupture - you don't always need surgery), and sports performance (e.g. muscle strength of the lower extremity/lower limb).

Caption: The psoas major muscle sitting deep on the skeletal system