For our last blog post of the year we will be moving down from the spine which was our previous focus to
the next – the hip joint. The hip joint is the connection of the lower limb to the trunk. This is one of the
larger joints in the body, which plays a crucial role in our ability to walk and complete other daily tasks. In
this blog post we will explore the anatomy of the hip joint, movements of the hip and common hip injuries
and conditions.
Anatomy of the hip joint.
As mentioned above the hip joint is one of the larger joints in the body and is one of two ball-and-socket
joints. The hip joint is a connection of the thigh bone (femur) and the trunk (pelvic bone). The rounded head
of the femur sits in the cup-like socket of the pelvis.
There are several components making up the hip joint structure:
– Bones: being the head of the femur (ball) and the acetabulum of the pelvis (socket).
– Cartilage: which lines both of these bone structures aiding in absorbing impact in the joint and
protecting the bone. The acetabular labrum is a fibrocartilagous collar which lines the acetabulum
which plays an important role in load transmission, regulation of synovial fluid and pressure
maintenance.
– Synovium: which is a thin layer of fluid around the bone which allows for smooth joint movement.
– Bursa: which is a fluid filled sack which provides cushioning and a smoother surface for the
structures around the joint.
– Ligaments: which connect the two bones together.
– Tendons: which connect the muscles to the bones.
– Muscles: found all-round the hip joint and facilitate movement. The muscle groups seen around the
hip joint include the famously know gluteus muscles (minimus, medius and maximus), pectineus,
piriformis, iliopsoas (hip flexor), adductors (inner thigh), gracilis, tensor fasciae latae (side of hip),
quadriceps (front of thigh) and hamstrings (back of thigh).
The hip joint is an extremely strong joint due to its reinforcement provided by the surrounding ligaments and
musculature as well as the joint capsule. Interestingly the joint capsule of the hip is thicker anterosurperiorly
(upper front of the joint) where the predominant stresses on the hip joint occur.
Cleveland Clinic 2023; OrthoInfo 2022; Physiopedia 2024.
Movements of the hip joint.
A ball-and-socket type joint allows for wide ranges of motion – the motions of the hip include hip flexion
with both a straight and bent knee, hip abduction (lateral outwards movement), hip adduction (lateral
inwards movement), hip extension, hip internal rotation and hip external rotation. Additionally, if we
combine these movements the hip can perform a circular motion known as circumduction. Movement of the
hip allows us to perform various important daily tasks such as sitting, standing and walking. The hip, for
such a mobile joint, also provides stability in terms of the supporting the body in standing upright. The
stability of the hip joint is provided by the shape of the acetabulum (socket) and the acetabular labrum
(fibrocartilagous collar).
The hip joint is said to have three important functions being:
i. Provide balance and support for the upper body
ii. Dynamic support and hold body weight
iii. Movement of the upper leg
Cleveland Clinic, 2023; Physiopedia 2024.
Common hip injuries and conditions.
1. Muscular strains or tears: A risk with all muscles in the body is a strain or tear to the muscle. As
mentioned above there are various muscles surrounding the hip joint, and the mechanism of injury will
determine which muscle may be at risk of injury. Some of the most common muscular strains occurring
in athletes occurs around the hip joint being the iliopsoas, adductor and hamstring muscle groups.
2. Bursitis: Swelling of the bursa of the hip joint. The hip has four bursa which are iliopsoas bursa,
ischiogluteal bursa, gluteus bursa and the most commonly affected with bursitis being the trochanteric
bursa.
3. Hip dislocation: As with other joint dislocations, this occurs when the joint structure becomes
misaligned, and the bones of the joint are separated. Dislocations are often traumatic in nature and
require a large force.
4. Broken bone: The bones of the hip are also susceptible to fractures and breaks, the circumstances of the
traumatic event will determine which bone is susceptible to breaking. Broken hips are big concern
among the elderly population as falls become more common and bones become weaker.
5. Osteoarthritis: Is the inflammation and degeneration of the hip joint, usually occurring overtime with
overuse and age.
6. Hip dysplasia: Is an anatomical abnormality in which your thigh bone (femur) does not sit correctly in
the pelvic bone.
Treatment of injuries and conditions of the hip depend largely on the cause. Various treatment modalities are
available including rest, ice, limiting activity, prescribed medications and surgeries. In terms of conservative
and rehabilitation, biokinetics therapy uses exercise prescription to improve range of motion, strength,
stability and functional use of the hip joint.
We have mentioned here some of the more common hip injuries and conditions, each with different
pathologies, causation and symptoms. Pain, stiffness, weakness and decreased range of motion are all
symptoms to watch our for in our hips joints whether you are athletic or not. Got a niggling hip we suggest
you see an appropriate practitioner for an evaluation and recommended treatment plan in order to keep a
‘happy hip’!
Cleveland Clinic 2023; OrthoInfo 2022; Physiopedia 2024.
References:
Cleveland Clinic. (2023). Hip Joint. Available from: https://my.clevelandclinic.org/health/body/24675-hip-
joint
Ortho Info. (2022). Hip Bursitis. Available from: https://orthoinfo.aaos.org/en/diseases–conditions/hip-
bursitis
Physiopedia. (2024). Hip Anatomy.