Sartorius 

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.

Adductor Brevis

Adductor Brevis is the smallest and shortest (hence the name brevis, meaning short in latin) of the three short adductor muscles. Groin strains are common injuries to the adductor muscles, which occur without a thorough warm-up or in individuals with chronically tight or weak adductor muscles.

Origin

• Inferior ramus of the pubic bone

Insertion

• Upper part of the linea aspera of the femur

Actions

• Hip adduction
  
• Hip flexion

Daily uses

• Bringing your second leg into the car

Adductor Longus

Adductor Longus is the middle of the three short adductor muscles. Groin strains are common injuries to the adductor muscles, which occur without a thorough warm-up or in individuals with chronically tight or weak adductor muscles

Origin

• Superior pubic ramus, just below the crest

Insertion

• Middle third of the linea aspera of the femur

Actions

• Hip adduction
• Hip flexion

Daily uses

• Bringing your second leg into the car

Adductor Magnus

Adductor Magnus is the largest groin muscle and is one of the two long adductor muscles (gracilis is the other). It is usually decribed as having two parts, hamstring and adductor parts.

Origin

• Adductor head: Inferior ramus of pubis and ischial ramus
• Hamstring head: Ischial tuberosity

Insertion

• Adductor head: Gluteal tuberosity, linea aspera and proximal supracondylar line
• Hamstring head: Adductor tubercle of the femur

Actions

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

Daily uses

• Bringing your second leg into the car

Biceps Femoris

Biceps Femoris is one of the three muscles which form the hamstring group forming the back of the thigh. 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 linea aspera 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

Daily uses

• Bending the knee to step over something

Superior Gemellus

Origin:

Ischial spine

Insertion:

Medial surface of greater trochanter of femur, in common with obturator internus

Action:

Rotates the thigh laterally; also helps abduct the flexed thigh

Gluteus Maximus

Gluteus Maximus is the largest and most superficial of the three gluteal muscles which forms the rounded shape of the buttocks.

Origin

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

Insertion

• Gluteal tuberosity of the femur
  
• Iliotibial band (ITB)

Actions

• Hip extension 
  
• External rotation of the hip

Daily uses

• Extension phase of walking upstairs

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

Daily uses

• Stepping sideways out of the bath

Gluteus Minimus

This is the smallest of the three gluteal muscles and sits underneath the gluteus medius.

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

Daily uses

• Getting out of a car

Gracilis

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

Daily uses

• Sitting with the knees pressed together

Obturator Internus

Origin:      Internal surface of obturator membrane and posterior bony margins of obturator foramen

Insertion: Medial surface of greater trochanter of femur, in common with superior and inferior gemelli

Action:     Rotates the thigh laterally; also helps abduct the thigh when it is flexed

Obturator Externus

Origin:      External surface of obturator membrane and anterior bony margins of obturator foramen

Insertion: Posteromedial surface of greater trochanter of femur

Action:     Rotates the thigh laterally; also helps adduct thigh

Pectineus

Pectineus is positioned between the Iliopsoas and Adductor Longus muscles and is part of the short adductor group with adductors brevis and longus.

Origin

• Upper front of the pubic bone

Insertion

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

Actions

• Hip adduction
  
• Hip flexion

Daily uses

• Kicking a football

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 as piriformis syndrome

Origin

• Anterior surface of the lateral sacrum

Insertion

• Greater trochanter of the femur

Actions

• External rotation of the hip 
  
• Hip abduction

Daily uses

• Taking the first leg out of the car

Quadratus Femoris

Origin: Lateral margin of obturator ring above ischial tuberosity

Insertion: Quadrate tubercle and adjacent bone of intertrochanteric crest of proximal posterior femur

Action: Rotates the hip laterally; also helps adduct the hip

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.

Semimembranosus 

Semimembranosus is the most medial of the three hamstring muscles. Chronically tight hamstrings are often a contributary factor to lower back pain andknee pain.

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.

Tensor Fasciae Latae

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

Iliacus

Origin:

Upper 2/3 of iliac fossa of ilium, internal lip of iliac crest, lateral aspect of sacrum, ventral sacroiliac ligament, and lower portion of iliolumbar ligament

Insertion:

Lesser trochanter

Action:

Flex the torso and thigh with respect to each other

Psoas