Hip + Pelvis - Anatomy Of The Human Body

BONES

The bones that make up the hip are the femur and the pelvis, and the hip is a synovial ball and socket joint.

Femur: The femur is the largest and strongest bone in the human body and the proximal head of this bone articulates with the pelvis.

Pelvis: The pelvis is also known as the pelvic girdle and this bone is different in males than it is in females. Woman have a more broad pelvis in order to give birth to a child, since it allows for a fetus to exit their body.

The pelvis is made up of the following 4 bones:

The (2) Hip Bones - These two hip bones are made up of three components which are the ilium, ischium, and the pubis.

1) Ilium: The largest and uppermost component of the hip bone is the ilium, and it also forms the superior aspect of the acetabulum.

2) Ischium: The posteroinferior aspect of the hip bone is created by the ischium, meaning it's at the back and bottom of the hip. It is located below the ilium and behind the pubis.

3) Pubis: At the anterior aspect of the lower hip, is where the pubis is located and this is the third bone which makes up the pelvis.

Sacrum - There are 5 fused bones that make up the sacrum. These 5 bones most often fuse during the teenage years, not at birth. The sacrum plays an important role in our bodies, especially when it comes to balance and also the transfer of weight from the upper body to the lower body.

Coccyx - There are 3-5 fused bones that make up the coccyx, but in some cases the bones aren't actually fused. The lowest portion of the tailbone is where the coccyx is located, and this bone also acts as an attachment point for ligaments and tendons. The coccyx also plays the role of a stabilizer when a person is in a seated position.

LIGAMENTS

Some of the major ligaments that are located in the hip/pelvis are:

Acetabulofemoral Ligaments - The acetabulofemoral joint is the main hip joint, and it is made up of the following ligaments:

1) Ischiofemoral Ligament: The ischiofemoral ligament attaches the greater trochanter of the femur to the acetabulum, which is the socket of the hipbone where the head of the femur fits. Excessive medial rotation of the hip is prevented by this ligament.

2) Iliofemoral Ligament: The iliofemoral ligament attaches the femur to the hip in two different places. One of them is at the superior aspect of the acetabulum, and the other is at the inferior iliac spine. This ligament limits hip extension and is the strongest of the hip joint ligaments.

3) Pubofemoral Ligament: The pubofemoral ligament attaches the femur to the pubis which is located on the inferior side of the hip joint.

Transverse Acetabular Ligament - The Transverse Acetabular Ligament attaches to the lower portion of the labrum and crosses the acetabular notch.

Ligament Of The Femoral Head - The ligament of the femoral head plays a role in helping attach the head of the femur to the acetabulum. This ligament has a triangular shape and is somewhat flattened.

BONE MARKINGS

There are many bone markings found on the hip and at the hip joint, but we will only be focusing on the following 4 hip markings and 1 femur marking:

1) Acetabulum: The ilium, ischium and pubis all meet at this bone marking which is a circular depression on the hip. The femur articulates here, forming the hip joint which is the acetabulofemoral joint.

2) Labrum: This bone marking is a cartilaginous structure that provides stability and support to the hip joint.

3) Obturator Foramen: This bone marking is a large opening that is formed by the ischium and pubis bones. There are nerves, veins and arteries that pass through here.

4) Pubic Symphysis: The Pubic Symphysis is located in between the right and left hip bones, and it is a piece of cartilage that attaches the two hip bones together.

5) Greater Trochanter: This bone marking is a bony protuberance that is located at the proximal end of the femur. The greater trochanter serves as an attachment point for many muscles.

MUSCLES

Anterior Muscles Of The Hip:

	Info about this muscle	Picture
Iliopsoas	The iliopsoas muscle is an anterior hip muscle which allows for flexion of the leg at the hip as well as lateral rotation. This muscle is a group of 3 muscles which all merge together at a common insertion point.
Pectineus	The Pectineus muscle flexes, adducts and medially rotates the hip. It is located on the anterior and medial side of the body, in the upper thigh.

Posterior Muscles Of The Hip:

	Info about this muscle	Picture
Quadratus Femoris	The Quadratus Femoris muscle laterally rotates and adducts the hip.This muscle is another one of the muscles of the gluteal region, and is located on the posterior side of the hip joint.
Piriformis	The piriformis laterally rotates and abducts the hip. It is a muscle located on the posterior side of the body, in the gluteal region.
Tensor Fascia Latae	The tensor fascia latae muscle works together with the gluteus medius and gluteus minimus muscles, to abduct and medially rotate the thigh. This muscle also extends the thigh, since it is a extensor muscle.
Gluteus Maximus	The gluteus maximus muscle is another one of the three gluteal muscles, and it is the largest. This muscle is located on the posterior side of the hip joint, and this muscle extends, abducts and laterally rotates the hip.
Gluteus Medius	The gluteus medius muscle is one of three gluteal muscles. This muscle is located on the lateral side of the upper buttock and this muscle abducts, medially rotates and extends the hip.
Gluteus Minimus	The gluteus minimus muscle is the final muscle which makes up the three gluteal muscles, and it is the smallest. This muscle is located right beneath the gluteus medius, and this muscle abducts, medially rotates and extends the thigh.

TENDONS

Iliotibial Tract (IT Band) - The iliotibial tract is a large tendon located on the lateral edge of the thigh, which attaches many muscles together. This tendon is also known as the iliotibial band and it connects the muscles of hip to the tibia. Therefore, it plays an important role in the movement of the thigh.

ORIGINS AND INSERTIONS

Muscle	Origin & Insertion Points
Iliopsoas	The Iliopsoas originates on the lumbar vertebrae and ilium and inserts on the lesser trochanter.
Tensor Fascia Latae	The Tensor Fascia Latae originates on the ilium and inserts on the lateral condyle of the tibia.
Gluteus Medius	The Gluteus Medius originates on the ilium and inserts on the greater trochanter.
Gluteus Minimus	The Gluteus Minimus also originates on the ilium and inserts on the greater trochanter.
Gluteus Maximus	The Gluteus Maximus originates on the ilium, sacrum and coccyx and inserts on the lateral condyle of the tibia.
Piriformis	The Piriformis originates on the sacrum and inserts on the greater trochanter.
Pectineus	The Pectineus originates on the pubis and inserts on the lesser trochanter.
Quadratus Femoris	The Quadratus Femoris originates on the ischium and inserts on the lesser trochanter.

JOINTS

There are 2 joints found in the hip region:

Acetabulofemoral Joint: The acetabulofemoral joint is the main hip joint, which is a synovial ball-and-socket joint. It is the articulation between the acetabulum and the femur.

Sacroiliac Joint: The sacroiliac joint is the articulation between the sacrum and ilium, of the pelvis. It is a synovial plane joint and our bodies have 2 of these joints, one on the right and one on the left.

MOVEMENTS

The different kinds of movements that occur in the hip are flexion and extension, abduction and adduction, internal rotation and external rotation and also circumduction. As you can see the hip is a very freely movable joint and can move in a variety of ways. This is because the hip is a synovial ball-and-socket joint, and because of this the shoulder is able to move in so many different ways.