Iliopsoas Is Sometimes Classified As Two Muscles, Iliacus and Psoas Major

Hip and pelvis

• Iliopsoas / Gluteus Medius / Gluteus Minimus / Gluteus Maximus / Piriformis / Pectineus / Sartorius / Rectus Femoris / Tensor Fasciae Latae / Biceps Femoris / Semitendinosus / Semimembranosus / Adductor Brevis / Adductor Longus / Adductor Magnus / Gracilis

Iliopsoas

Iliopsoas is sometimes classified as two muscles, Iliacus and Psoas major.

Origin

• Inner surface of the Ilium
• Base of the sacrum
• Sides of the bodies of T12-L5

Insertion

• Lesser trochanter of the femur

Actions

• Flexion of the hip
• Lateral rotation of the hip
• Flexes torso when the legs are fixed (e.g. laying to sitting)

Innervation

• Femoral nerve and branches of the lumbar plexus

Daily uses

• Climbing a step

Gluteus Medius

Gluteus Medius is an important muscle in controlling the level of the hips. Weaknesses in gluteus medius often result in a trendelenburg sign, an abnormal gait cycle where the hip of the swinging leg drops down, rather than raises up. This results in increased degrees of knee flexion in order to clear the ground.

Origin

• Outer surface of the ilium, just below the crest

Insertion

• Greater trochanter of the femur

Actions

• Hip abduction
• Posterior fibres externally rotate the hip
• Anterior fibres internally rotate the hip

Innervation

• Superior gluteal nerve

Daily uses

• Stepping sideways out of the bath

Gluteus Minimus

Origin

• Outer surface of the ilium, below the origin of Gluteus medius

Insertion

• Greater trochanter of the femur

Actions

• Hip abduction
• Internal rotation of the hip

Innervation

• Superior gluteal nerve

Daily uses

• Getting out of a car

Gluteus Maximus

Gluteus Maximus is the largest and most superficial of the three gluteal muscles.

Origin

• Posterior crest of the ilium
• Posterior surface of the sacrum

Insertion

• Glutealtuberosity of the femur
• Iliotibial band (ITB)

Actions

• Hip extension
• External rotation of the hip

Innervation

• Inferior gluteal nerve

Daily uses

• Extension phase of walking upstairs

Piriformis

The Piriformis muscle is an important muscle. The sciatic nerve passes underneath this muscle on its route down to the posterior thigh. In some individuals the nerve can actually pass right through the muscle.

This can lead to sciatica symptoms due to a condition known aspiriformis syndrome.

Origin

• Anterior surface of the lateral sacrum

Insertion

• Greater trochanter of the femur

Actions

• External rotation of the hip
• Hip abduction

Innervation

• Branch of the sacral plexus

Daily uses

• Taking the first leg out of the car

Pectineus

Pectineus is positioned between the Iliopsoas and Adductor Longus muscles.

Origin

• Upper front of the pubic bone

Insertion

• Upper medial shaft of the femur, inferior to the lesser trochanter

Actions

• Hip adduction
• Hip flexion

Innervation

• Femoral nerve

Daily uses

• Kicking a football

Sartorius Muscle

The Sartorius is a two joint muscle and so is weak when the knee is flexed and the hip is flexed at the same time. It works better during single movements.

Origin

• Area between the ASIS (Anterior Superior Iliac Spine) and AIIS (Anterior Inferior Iliac Spine)

Insertion

• Anterior part of the medial condyle of the tibia

Actions

• Flexion of the hip
• Flexion of the knee
• External rotation of the hip as it flexes the hip and knee
• Abducts the hip

Innervation

• Femoral nerve

Daily uses

• Sitting in a cross-legged position

Rectus Femoris

The Rectus Femoris muscle is part of the Quadriceps muscle group. It is the only muscle of the group which crosses the hip joint and is a powerful knee extensor when the hip is extended, but is weak when the hip is flexed.

Origin

• Anterior Inferior Iliac Spine (AIIS)

Insertion

• Top of the patella and the patella tendon to the tibialtuberosity

Actions

• Flexion of the hip
• Extension of the knee

Innervation

• Femoral nerve

Daily uses

• Kicking a football

Tensor Fasciae Latae Muscle

The Tensor Fasciae Latae is a small muscle which attaches inferiorly to the long thick strip of fascia, known at the iliotibial band (ITB)

Origin

• Anterior Iliac crest and ilium

Insertion

• Lateral condyle of the tibia via the Iliotibial band

Actions

• Flexion of the hip
• Hip abduction

Innervation

• Superior gluteal nerve

Daily uses

• Keeping one foot in front of the other when walking

Biceps Femoris

Biceps Femoris is one of the three muscles which form the hamstring group. The muscle is often described as having a long head (the attachment from the ischium) and a short head (attached to the femur).

Origin

• Tuberosity of the ischium
• Lower1/2 of the lineaaspera of the femur
• Lateral supracondylar ridge

Insertion

• Lateral condyle of the tibia
• Head of the femur

Actions

• Hip extension
• Knee flexion
• Lateral rotation of the hip when the knee is flexed

Innervation

• Tibial part of the sciatic nerve

Daily uses

• Bending the knee to step over something

Semitendinosus

When running the hamstrings act eccentrically to slow down the knee extension motion. Hamstring strains are common in individuals with chronically tight hamstrings or who do not warm-up thoroughly.

Origin

• Ischialtuberosity

Insertion

• Upper medial surface of the tibia

Actions

• Hip extension
• Knee flexion
• Internal rotation of the hip when the knee is flexed

Innervation

• Tibial part of the sciatic nerve

Daily uses

• Bending the knee to step over something

Semimembranosus

Semimembranosus is the most medial (inside) of the three hamstring muscles and along with the semitendinosus muscle provides dynamic stability to the knee joint.

Origin

• Ischialtuberosity

Insertion

• Posterior part of the medial condyle of the tibia

Actions

• Hip extension
• Knee flexion
• Internal rotation of the hip when the knee is flexed

Innervation

• Tibial part of the sciatic nerve

Daily uses

• Bending the knee to step over something

Adductor Brevis

Adductor Brevis is the smallest and shortest of the five adductor muscles with the others being Adductor longus, Adductor magnus, Gracilis and Pectineus.

Origin(where it starts from)

• The pubic bone

Insertion(where it inserts into)

• Upper part of the femur or thigh bone.

Actions(what does it do?)

• Hip adduction
• Hip flexion

Which nerve makes it move?

• Obturator nerve

Everyday uses

• Bringing your second leg into the car

Adductor Longus

Adductor Longus is the middle of the three short adductor muscles (adductor brevis and pectineus are the other two). The adductor magnus and gracilis are the two long adductor muscles which go from the pubic bone to the knee.

Origin(where it starts from)

• Superior pubic ramus, just below the crest

Insertion(where it inserts into)

• Middle third of the lineaaspera of the femur

Actions

• Hip adduction
• Hip flexion

Which nerve makes it move?

• Obturator nerve

Everyday uses

• Bringing your second leg into the car

Adductor Magnus

Adductor Magnus is the largest of the adductor muscles and with the gracilis muscle forms the long adductor group.

Origin(where it starts from)

• Adductor head: Inferior ramus of pubis and ischialramus
• Hamstring head: Ischialtuberosity

Insertion(where it inserts into)

• Adductor head: Glutealtuberosity, lineaaspera and proximal supracondylar line
• Hamstring head: Adductor tubercle of the femur

Actions

• Adductor head: Adducts and flexes hip
• Hamstring head: Extends hip

Which nerve makes it move?

• Adductor head: Obturator nerve
• Hamstring head: Sciatic nerve

Everyday uses

• Bringing your second leg into the car

Gracilis

Gracilis is another muscle which works in conjunction with the groin muscles, or adductors.

Origin

• Lower pubic body, near the pubic symphesis

Insertion

• Upper medial surface of the tibia (pes anserine insertion)

Actions

• Adducts hip
• Flexes knee
• Internally rotates the hip when the knee is flexed

Innervation

• Obturator nerve

Daily uses

• Sitting with the knees pressed together