GENERAL INFORMATION
The psoas major is a long muscle located in the hip region. Along with the iliacus muscle, it is part of the iliopsoas muscle group. The psoas major plays a vital role in hip flexion, posture, as well as lower back stability.
ORIGIN
The psoas major originates from the lumbar vertebrae (T12-L5) and their intervertebral discs.
INSERTION POINT
It inserts onto the lesser trochanter of the femur, which is a bony prominence on the inner aspect of the thigh bone.
MAJOR ARTERIES
This muscle receives its blood supply from branches of the lumbar arteries, including the lumbar branch of the iliolumbar artery.
NEURAL INNERVATION
The psoas major muscle is innervated by the anterior rami of the lumbar nerves (L1-L3), which provide sensory as well as motor innervation to the lower limb.
TRIGGER POINT
Trigger points in the psoas major muscle can cause pain and discomfort in the lower back, hip, as well as groin region.
CONCENTRIC FUNCTION
During contraction, the psoas major muscle acts to flex the hip joint, bringing the thigh bone closer to the torso.
ECCENTRIC FUNCTION
The eccentric function of the psoas major muscle occurs during the controlled lengthening of the muscle, such as during the lowering phase of a squat or lunge.
ISOMETRIC FUNCTION
The psoas major muscle can contract isometrically to stabilise the lumbar spine as well as the pelvis.
RELATED MUSCLE SCIENTIFIC NAMES
- Iliopsoas (combination of iliacus and psoas major)
- Iliacus
ANTAGONIST MUSCLES
- Gluteus maximus
- Hamstrings (e.g., biceps femoris, semitendinosus, semimembranosus)
COMMON INJURIES
- Strains or tears of the psoas major muscle: Caused by overuse or sudden movements, resulting in sharp pain, swelling, and muscle weakness.
- Hip flexor tendinitis: Inflammation due to repetitive stress, causing pain and restricted movement.
- Muscle imbalances lead to pelvic and lower back pain from poor posture, repetitive stress, or improper biomechanics.
EXERCISES
- Hip flexion exercises: Include leg raises and knee raises to strengthen the psoas major and improve hip mobility.
- Squats and lunges Engage the psoas major and other hip and leg muscles, promoting overall lower-body strength.
- Core exercises with hip flexion components: Hanging leg raises and bicycle crunches to target the psoas major and improve core stability.
STRETCHES
- Kneeling hip flexor stretch: Stretches the psoas major and other hip flexors, alleviating tightness and improving flexibility.
- Supine figure-four stretch: Targets the hip area, releasing tension in the iliopsoas and surrounding muscles.
- Seated butterfly stretch: Improves flexibility in the hip region, promoting a better range of motion.
- Pigeon pose (variation): This is a deep stretch of the hip and lower back, ideal for releasing tension and enhancing flexibility.
