Section 01 of 20
Introduction
Iliopsoas is the name for the combined psoas major and iliacus, which share a common tendon. Psoas major arises from the lumbar spine and iliacus from the iliac fossa, and together they cross the front of the hip joint.
It is the main hip flexor and a link between the trunk and the leg, which is why it is often discussed in posture, low back, and hip pain.
Section 02 of 20
Origin
| Origin | Psoas major: sides of the T12–L5 vertebral bodies and discs, and the transverse processes of L1–L5. Iliacus: the iliac fossa, inner lip of the iliac crest, and ala of the sacrum. |
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An anatomical image for this section will be added when verified source media becomes available.
Section 03 of 20
Insertion
| Insertion | Lesser trochanter of the femur by a common tendon. |
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An anatomical image for this section will be added when verified source media becomes available.
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Actions
No dedicated action video is currently available. This movement is explained below and video will be added when verified source media becomes available.
| Primary action | Hip flexion. |
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| Secondary actions | Trunk flexion when the legs are fixed, lumbar stabilization, and weak lateral rotation. |
| Movement at the joint | Hip joint (and lumbar spine for psoas major). |
| Heads / fiber groups | Two muscles, psoas major and iliacus, with a common tendon. |
| Functional examples | Walking and running; climbing stairs; sitting up from lying; kicking. |
Hip flexion
The strongest flexor of the thigh at the hip.
Trunk flexion
When the legs are fixed, brings the trunk forward (as in sitting up from lying).
Lumbar stabilization and lateral rotation
Psoas major helps stabilize the lumbar spine and may assist slight lateral rotation of the thigh.
Section 05 of 20
Nerve Innervation
| Nerve | Psoas major: anterior rami of L1–L3 (some sources L2–L4). Iliacus: femoral nerve, L2–L3. |
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The lumbar plexus lies within psoas major, and the femoral nerve runs between psoas and iliacus. Thigh numbness, weakness, or a knee that gives way may reflect nerve problems, not only muscle tightness.
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Blood Supply
| Blood | Lumbar branches of the iliolumbar artery and the iliac branch of the iliolumbar artery, with contributions from the deep circumflex iliac and femoral circumflex arteries. |
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Section 07 of 20
Pictures and Visual Anatomy
An anatomical image for this section will be added when verified source media becomes available.
Section 08 of 20
Functional Movement
Iliopsoas lifts the leg with each step of walking and running, is heavily used in climbing stairs and sitting up, and is kept in a shortened position by prolonged sitting.
Section 09 of 20
Synergists and Antagonists
Synergists: rectus femoris, sartorius, pectineus, and tensor fasciae latae. Antagonists: gluteus maximus and the hamstrings (hip extension).
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Palpation and Location
Client position and technique
Palpation is indirect and requires clear consent and communication. With the client supine and the knees bent, contact the area just inside the anterior superior iliac spine and move slowly inward and downward along the ilium, following the client's breathing. Lateral to the rectus abdominis, wait for the abdominal wall to soften.
Protect nearby structures
The abdominal aorta, iliac vessels, femoral artery and nerve, kidneys, and bowel are nearby. Use slow, light pressure, stay lateral to any pulse, and stop at pain, tingling, or unusual pulsation. Avoid the area in pregnancy, after recent abdominal surgery, or with known aneurysm.
Section 11 of 20
Massage Therapy Relevance
Because it links the lumbar spine and pelvis to the femur, tightness or weakness of iliopsoas is often discussed in relation to sitting posture, anterior pelvic tilt, and low back or front-hip discomfort. Many other structures can cause the same symptoms.
Section 12 of 20
Dysfunction: What Happens When Movement Goes Wrong
Changes in how a muscle works can change how a joint moves. The points below describe possibilities that may be associated with altered muscle function; they are not diagnoses, and one muscle is never assumed to be the sole cause of a problem.
When the muscle is weak
Weakness may reduce the ability to lift the leg and may be associated with a shorter stride and more work by the rectus femoris and tensor fasciae latae.
When it is tight or shortened
Tightness may be associated with limited hip extension, anterior pelvic tilt, and front-hip or low back discomfort, especially after long periods of sitting.
When it is overused
Repeated hip flexion in running, kicking, and cycling may overload the muscle and tendon and may contribute to groin or front-hip pain.
When it is strained
A strain may cause front-hip or groin pain with resisted hip flexion; hip joint, hernia, and lumbar causes can look similar.
When it is inhibited or others compensate
Reduced activation may be associated with poor hip flexion control and more work by the rectus femoris and other flexors.
When it does not coordinate well with synergists and antagonists
Poor coordination with the abdominals and gluteus maximus may alter pelvic position and may be associated with low back or hip symptoms.
Section 13 of 20
Conditions, Pathologies, and Pain Relationships
Hip flexor tightness
A shortened iliopsoas may limit hip extension and may be associated with an increased lumbar curve.
Iliopsoas tendinopathy and snapping hip
A snapping or catching feeling at the front of the hip may involve the tendon crossing the hip joint and bursa.
Psoas strain
Sprinting, kicking, and sudden hip flexion can strain the muscle or tendon and cause groin or front-hip pain.
Differential considerations
Hip joint problems, hernia, femoral nerve entrapment, abdominal or pelvic conditions, and lumbar referral can all cause groin, front-hip, or low back symptoms.
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Example Clinical Relationship
A cyclist reports a catching feeling at the front of the hip and tightness when standing after long rides. The iliopsoas tendon may be involved, and the pattern may be associated with tendinopathy or a snapping hip, but the hip joint and lumbar spine can look similar. Gentle work on the anterior hip flexors may support comfort, while sudden severe pain, a groin bulge, or new leg weakness needs referral.
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Massage and Treatment Approaches
For healthy, non-acute tissue, use secure draping and clear consent. Begin with light effleurage and gentle compression over the anterior thigh and hip flexors, add gentle hip mobilization within comfort, and keep any indirect abdominal work brief, light, and guided by client feedback.
| Positioning | Supine with the knees bent and supported by a bolster, or side-lying with the top leg supported. |
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| Regional work | Consider the quadriceps, rectus femoris, tensor fasciae latae, sartorius, abdominals, and lumbar region when assessment supports it. |
| Avoid | Deep pressure in the lower abdomen or over the femoral triangle; anything that reproduces leg pain, tingling, or a pulse-like sensation. |
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Precautions and Contraindications
Precautions and contraindications
- Pregnancy, recent abdominal or pelvic surgery, or known abdominal aortic aneurysm: do not perform deep abdominal work.
- Use caution with hernias, inflammatory bowel disease, or abdominal pain of unknown cause.
- Use caution with anticoagulant use or easy bruising.
- Always obtain explicit consent and use secure draping for hip and groin area work.
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Red Flags and When to Refer
Red flags and referral
- Severe or worsening abdominal pain, fever, or a pulsating mass in the abdomen.
- Groin bulge, testicular pain, or blood in the urine.
- Sudden hip or groin pain after a fall, or inability to bear weight.
- New leg weakness, numbness in the thigh, or bladder or bowel changes.
Section 18 of 20
Study Summary
Attachments
Origin: T12–L5 and transverse processes (psoas); iliac fossa (iliacus). Insertion: lesser trochanter.
Actions
Strongest hip flexion; trunk flexion when the legs are fixed.
Supply
Lumbar plexus (L1–L3) and femoral nerve (L2–L3); iliolumbar artery.
Section 19 of 20
Instructor Narration
Open narration transcript
Iliopsoas is the combined psoas major and iliacus, which share a tendon and are the strongest hip flexors.
Psoas major arises from the sides of the T12 to L5 vertebral bodies and discs and the lumbar transverse processes. Iliacus arises from the iliac fossa. They insert together on the lesser trochanter of the femur.
Iliopsoas flexes the hip, brings the trunk forward when the legs are fixed, and psoas helps stabilize the lumbar spine. Rectus femoris, sartorius, and pectineus help it, and gluteus maximus and the hamstrings oppose it.
Psoas is supplied by the lumbar plexus, roots L1 to L3, and iliacus by the femoral nerve. The iliolumbar artery provides the blood supply.
Palpation is indirect. Obtain consent, place the client supine with the knees bent, and move slowly inward from the anterior superior iliac spine. Stay lateral to any pulse and stop at pain or tingling.
Hip flexor tightness, snapping hip, strain, hernia, and nerve problems can overlap. Refer a pulsating abdominal mass, severe abdominal pain, groin bulge, new leg weakness, or bladder or bowel changes.
Remember: lumbar spine and iliac fossa to the lesser trochanter, hip flexion, L1 to L3 and femoral nerve.
Section 20 of 20