1. Iliopsoas (= Psoas Major + Iliacus):
- Origin: lumbar vertebrae bodies (psoas major) + ventral surface of ilium (iliacus).
- Insertion: Lesser Trochanter of femur.
- FUNCTION: Main FLEXOR of the HIP joint (advances the limb).
- Nerve: branches from lumbar plexus.

2. Tensor Fasciae Latae:
- Origin: tuber coxae (hook bone).
- Inserts into the fascia lata of the thigh (which then transmits force to patella).
- Function: tenses the lateral thigh fascia + flexes hip + extends stifle.
- Nerve: Cranial Gluteal nerve.

3. Psoas Minor:
- Small muscle below the lumbar vertebrae, inserts on shaft of ilium.
- Function: minor flexion of pelvis on lumbar spine.
- (This is the 'tenderloin/fillet' in beef.)

HIP FLEXORS

These muscles bring the limb FORWARD (= flexion of hip = protraction).

1. ILIOPSOAS:
The combined muscle of two parts:
• Psoas major — from bodies and transverse processes of last thoracic + lumbar vertebrae.
• Iliacus — from ventral surface of ilium.
Both join into a single tendon and insert on the lesser trochanter of femur.
Function: The MAIN flexor of the hip. Pulls the femur forward → essential for advancing the limb in walking/running. Also flexes the lumbar spine.

2. TENSOR FASCIAE LATAE:
From the tuber coxae (hook bone), runs down the side of the thigh, and inserts into the broad fascia of the thigh (fascia lata). When it contracts, it tenses the fascia and indirectly extends the stifle (because the fascia connects to the patella). It also helps flex the hip.

3. PSOAS MINOR:
A smaller, more medial muscle. From bodies of last thoracic + first lumbar vertebrae, inserting on the body of ilium. Functionally minor — flexes pelvis on the spine.
Note: In butchery, the psoas major + minor + iliacus together make the 'tenderloin/fillet' — the most tender meat (because it never bears weight, it stays soft).

UG MEMORY: Iliopsoas → 'lesser trochanter, hip flexor, lumbar plexus'.