What Is the Hip? Hip Anatomy and Neighbouring Regions

The hip is an anatomical region comprising the joint formed by the socket in the pelvic bone and the femoral head at the upper end of the thigh bone, as well as the muscles, ligaments, tendons and other soft tissues surrounding this joint.

Summary: The hip is a ball-and-socket joint that permits load transfer and movement between the trunk and thigh. The pelvis, pelvic bone, buttock and thigh are neighbours to one another; however, they do not describe the same anatomical region. Hip pain may be felt in the groin, outer side, buttock, thigh or around the knee. Although the location of pain may provide a clue about the likely source, it is not sufficient to establish a diagnosis. In cases of trauma, circulatory or neurological signs, or rapidly increasing severe pain, evaluation is required without delay.

In everyday language, the terms "hip", "buttock" and "pelvic bone" are often used interchangeably. However, the hip joint between the femoral head and pelvis contributes to the transfer of body weight and permits the thigh to move in three anatomical planes. Understanding this distinction makes it easier to describe a complaint felt in the groin, outer hip, buttock or thigh more clearly.

Where is the Hip Located on the Body?

The hip is located on the right and left sides of the pelvis, at the junction of the lower part of the trunk with the upper region of the thigh. The deep hip joint is formed between the socket in the pelvic bone and the femoral head. The area outwardly referred to as the hip encompasses not only the joint but also the muscles, adipose tissue, tendons and other soft tissues.

The approximate boundaries of the anatomical region can be described as follows:

• Anteriorly: It is adjacent to the inguinal ligament and the superior anterior aspect of the thigh.
• Laterally: It is the region of the bony prominence felt on the outer side of the pelvis and the soft tissues overlying it.
• Posteriorly: It borders on the posterior aspect of the pelvic bone, the sacroiliac joint and the hip muscles.
• Inferiorly: After the hip crease, the region transitions to the thigh.
• Medially: It is closely associated with the muscles, blood vessels, nerves and structures around the groin and pelvis.

A hip joint is located on the right and left sides of the body. The joint itself is not at the surface but lies beneath layers of thick muscle and soft tissue. Therefore, when a person says "my hip hurts", they may be referring to the groin, outer hip, buttock region or upper thigh.

Whether the pain is felt at a small point that can be indicated with a finger or over a wide area is also important. Whether the complaint is located deeply or superficially; and how it changes with sitting, walking, using stairs or lying on it helps the assessment.

What Structures Does Hip Anatomy Comprise?

Hip anatomy comprises the femoral head, acetabulum, articular cartilage, labrum, capsule, ligaments, muscles, tendons and bursae. These structures work together to distribute load, maintain joint stability and produce controlled movement. To understand which tissue is the source of the problem, soft tissues around the joint are also evaluated alongside the bones.

The hip joint is a ball-and-socket type joint. The ball-shaped femoral head is seated in the acetabulum, a bony socket on the pelvis. The principal structures are as follows:

• Femoral head and neck: The femoral head is the spherical portion of the joint. The femoral neck provides a connection between the head and the shaft of the femur.
• Acetabulum: The bony socket that surrounds the femoral head. Three bony portions called the ilium, ischium and pubis contribute to the formation of this socket.
• Articular cartilage: Covers the opposing surfaces of the femoral head and acetabulum. It assists in distributing contact pressure and reducing friction during movement.
• Labrum: A fibrocartilage ring that surrounds the rim of the acetabulum. It contributes to the functional depth of the socket and joint congruence.
• Joint capsule: Surrounds the joint space from the outside. The thickness and tension of the capsule varies according to the direction of movement.
• Ligaments: Together with the capsule, they limit excessive movement in certain directions and support joint control during standing.
• Muscles and tendons: Produce the forces that flex, extend, abduct, adduct and rotate the hip.
• Bursae: Fluid-filled sacs located in areas where bone, tendon and muscle pass in close proximity; they assist in reducing friction.

The functions of joint structures are not independent of one another. For example, due to pain, the hip muscles may not be used sufficiently, which can alter gait pattern and the load transferred to the opposite leg. Conversely, muscle or tendon problems can also cause pain and restricted movement around the joint.

What is the Relationship Between the Pelvis, Pelvic Bone and Hip Joint?

The pelvis is a bony ring that permits load transfer between the trunk and the lower limbs. The pelvic bones form the right and left sides of this ring; the hip joints are the mobile connections between the pelvis and the femur. The hip joint is formed by the placement of the femoral head into the acetabulum of the pelvic bone.

Although these terms are interrelated, they do not describe the same structure:

• Pelvis: The bony whole formed by the right and left pelvic bones and, posteriorly, the sacrum and coccyx.
• Pelvic bone: The broad bone located on either side of the pelvis. It consists of the ilium, ischium and pubis regions.
• Hip joint: The ball-and-socket joint established between the acetabulum and the femoral head.
• Femur: The primary bone of the thigh. The head portion at its upper end enters the hip joint socket.
• Sacroiliac joint: The connection between the sacrum and the pelvic bone; it is distinct from the hip joint.

This anatomical arrangement helps to transfer the load coming through the spine to the pelvis and then to both lower limbs. During walking, the load alternates between sides; the muscles limit excessive pelvic tilt and prevent uncontrolled movement of the trunk.

The term "hip bone" in everyday speech can be applied to the entire region. In medical assessment, however, the pelvic bone, hip joint, sacroiliac joint and femur are treated as separate structures. This distinction is important in order to identify the source of the pain.

What is the Difference Between the Hip, Buttocks and Thigh?

The hip is the joint region where the pelvis meets the leg; the buttocks is an everyday term that describes the external body contour around the pelvis. The thigh is the upper leg region that extends from the hip joint to the knee. Since these areas are adjacent to one another, the location of complaints in everyday conversation may be described using different terms.

• Hip: Includes the hip joint and the surrounding muscles, ligaments, tendons, bursa and other soft tissues.
• Buttocks: An everyday term without precise anatomical boundaries. It describes the external appearance created by the sides of the pelvis and the muscle and fatty tissue in this region.
• Thigh: Lies between the hip and the knee. Contains the femur, the surrounding muscles, blood vessels, nerves and soft tissues.
• Deep buttock region: An everyday term used for the gluteal muscles and the tissues overlying them at the back of the hip.

Region	Anatomical equivalent	Approximate boundaries	Common description
Hip	The joint and surrounding area where the pelvis and femur meet	The junction of the body and leg	Groin, outer hip or back of the hip
Buttocks	The external body contour around the pelvis	Below the waist and at the sides of the pelvis	Lateral prominences
Thigh	The femur and surrounding tissues	Between the hip and knee	Upper leg
Deep buttock region	The gluteal muscles and overlying tissues	The posteroinferior region of the pelvis	Back of the hip

In everyday speech, 'buttock pain' may refer to symptoms from the tendons and bursa of the outer hip, the pelvic bone, or pain referred from the lower back. 'Thigh pain' may arise from the muscles or may be pain referred from the hip joint. The location of the complaint should be interpreted together with the clinical examination findings.

What Movements Does the Hip Joint Allow?

The hip joint allows the leg to move forward, backward and sideways, to bring it towards the midline and to rotate it inward and outward. These movements occurring in three anatomical planes are coordinated during walking, sitting, standing, using stairs and changing direction. The muscles around the joint also contribute to keeping the pelvis and body in balance.

The basic movements of the hip are as follows:

• Flexion: Lifting the thigh towards the body. Used during sitting, bending forward and climbing steps.
• Extension: Moving the leg backward. Plays a role in propelling the body forward while walking and in standing up from a seated position.
• Abduction: Opening the leg sideways away from the midline of the body. Helps to maintain balance of the opposite pelvis during walking.
• Adduction: Bringing the leg toward the midline.
• Internal rotation: Turning the femur inward on its long axis.
• External rotation: Turning the femur outward.
• Combined movements: In activities such as squatting, turning and putting on shoes, multiple movement directions are used simultaneously.

Plane of movement	Basic movements	Everyday example
Anteroposterior plane	Flexion and extension	Sitting, standing, walking
Lateral plane	Abduction and adduction	Stepping sideways, maintaining pelvic balance
Transverse plane	Internal and external rotation	Changing direction, turning the foot inward or outward

Range of movement varies from person to person. Age, joint structure, muscle flexibility, previous injuries and pain may affect this range. Restricted movement does not always indicate a problem in the same tissue; conditions arising from the joint, muscle, tendon or nerve can produce similar restriction.

In Which Areas Can Hip Pain Be Felt?

Hip pain may be felt in the groin, outer hip, deep buttock region, thigh or around the knee. The location of the pain provides guidance as to the possible source; however, it does not establish a diagnosis on its own. The hip joint, gluteal tendons, bursa, lumbar spine, sacroiliac joint and surrounding nerves can produce similar complaints.

Regional assessment of hip pain has also been addressed in a 2014 study entitled "Evaluation of the patient with hip pain" (PMID 24444505). The main locations are as follows:

• Groin and front of the hip: Pain arising from structures inside the joint is often felt in the groin. The complaint may extend to the front of the thigh or around the knee.
• Lateral hip: Felt around the bony prominence on the outer side. Lying on the side, prolonged walking, using stairs or climbing an incline may aggravate the complaint.
• Back of the hip and deep buttock region: May be associated with muscles, tendons, sacroiliac joint, lumbar spine or nerves.
• Thigh: Pain referred from the hip joint may be felt in the front or side of the thigh. Problems affecting the thigh muscles may also show a similar distribution.
• Around the knee: In some hip problems, pain may become more prominent at the knee. For this reason, alongside knee examination, assessment of the hip may also be required.
• Pain radiating down the leg: If numbness, tingling or weakness accompanies the symptoms, the nerves and lumbar region require further examination.

The assessment includes questions about the onset of pain, its relation to injury, its nocturnal behaviour and how it changes with movement. Accompanying findings such as limping, a sensation of catching in the joint, loss of motion, numbness or fever help in distinguishing the source.

When Should Hip Region Complaints Be Evaluated?

The timing of presentation for hip complaints varies depending on the severity of symptoms, the manner of onset and accompanying findings. Inability to bear weight following trauma, signs of circulatory or nerve disturbance, altered consciousness and rapidly worsening severe pain require emergency evaluation. In cases of recurring pain that limits daily function, medical examination should not be delayed.

If any of the following symptoms occur, call 112 or seek emergency care:

• Sudden shortness of breath, chest pain, fainting, coughing up blood, or rapid heartbeat
• Severe pain that is disproportionate to the injury, persistent or rapidly worsening
• Pain that markedly worsens with passive movement
• Tense swelling, new numbness or weakness
• Coldness, paleness or discolouration of the limb
• Newly developed loss of sensation or muscle weakness
• New confusion or speech that makes no sense; fever is not required
• Severe pain, deformity, inability to move or inability to bear weight
• Uncontrolled bleeding
• Marked shortening of the leg or abnormal rotation following trauma

In the following situations, medical assessment should be obtained the same day:

• One-sided leg swelling, pain or calf tightness
• Increased redness, heat, swelling or discharge at the wound site; fever need not be present
• Wound edges opening
• Fever of 38 °C or above, persistent fever, chills or general deterioration
• If the discharge summary specifies a lower fever threshold, exceeding that threshold
• New severe pain or inability to bear weight following a fall or impact
• Pain and loss of motion developing within hours

Even if emergency findings are not present, if pain is recurring, causing limping, disrupting sleep or significantly limiting daily activities, orthopaedic evaluation should be arranged. During examination, the lumbar spine, pelvis, knee, muscles and nerves may be assessed alongside the hip joint; the need for imaging is determined based on the findings.

What Can Be Done in Daily Life to Protect Hip Health?

To support hip health, it is important to move regularly, strengthen the surrounding muscles in a balanced way, break up long periods of immobility, and increase physical load gradually. The appropriate activity level is not the same for everyone; it should be personalised taking into account age, balance, bone health, existing medical conditions and the cause of pain.

In daily life, the following points can be considered:

• Break up immobility: Periodically standing up during prolonged sitting, taking short walks and changing sitting position can reduce stiffness.
• Move regularly: Walking, swimming or appropriate resistance training can support overall movement capacity. Activity choice should be made according to the person's health status.
• Exercise muscles in a balanced way: Strengthening the lateral, anterior and posterior hip muscles together with the core muscles contributes to movement control.
• Increase load gradually: Walking distance, running duration, incline or resistance used should not be increased simultaneously or suddenly.
• Wear footwear appropriate for the activity: Shoes should fit well, be unworn and suitable for the activity being undertaken.
• Reduce fall risk: Slippery or loose floor surfaces in the home should be made safe, passage areas should be well lit and, if necessary, an appropriate assistive device should be used.
• Monitor pain behaviour: If symptoms worsen progressively with activity, persist for a long time afterwards or cause loss of function, load should be reduced and assessment sought.
• Personalise exercise: Movements should be performed as demonstrated by the physiotherapist or doctor. Attempting to follow a general programme by pushing through pain in a joint may not be appropriate.

Exercise, physiotherapy and other non-surgical approaches are planned according to the cause of the symptoms. In selected cases, medication or injection options can be considered; injection types do not all have the same level of evidence or duration of effect. Prescribed medications should not be started, stopped or changed at the person's own discretion.

Frequently asked questions

Where is the hip in the body?

The hip is located where the trunk meets the thigh, on the right and left sides of the pelvis. The deep hip joint is formed between the acetabulum in the pelvic bone and the femoral head. The externally visible hip area encompasses not only the joint but also its muscles, tendons, bursae, fatty tissue and other soft tissues.

Where is the hip in women?

In women, the hip encompasses the lateral, anterior and posterior regions between the pelvic bone and the thigh. Although the shape of the pelvis and external body contour may vary between individuals, the basic components of the hip joint are the same: the femoral head sits in the acetabulum on the pelvis; surrounding muscles and ligaments contribute to movement control.

Where are the hip and thigh?

The hip is the joint and anatomical region where the pelvis meets the femur. The thigh is the upper leg portion extending from the hip joint to the knee joint. The main bone of the thigh is the femur; the head of the femur at its upper end sits in the acetabulum, forming the spherical component of the hip joint.

What are other names for the hip?

In everyday language, the terms "buttock" or "backside" may be used for the hip; however, these words do not precisely correspond to the same anatomical structure. "Buttock" refers to the external body contour, whilst "backside" mostly describes the posterior gluteal tissue. In medical use, the "hip region" is distinguished from the deeper "hip joint".

Where are the upper hip and lower hip?

Upper hip in everyday use refers to the lateral projections of the pelvic bone and the area near the lower back. Lower hip describes the region of the hip crease and the beginning of the thigh. These terms do not have precise anatomical boundaries; when describing pain, it is more informative to specify anterior, lateral, posterior and groin location.

Where is the hip; where is the buttock?

The hip is the joint and surrounding tissues where the pelvis meets the thigh. The buttock is a colloquial term describing the broader external contour visible on either side of the pelvic bone. Whilst the buttock appearance is influenced by bone structure as well as muscle and fat tissue, the hip joint lies beneath this external outline, deeper within the body.

What is the anatomical name of the hip bone?

The anatomical name of the hip bone is os coxae. Each of these bones, found on the right and left, consists of ilium, ischium and pubis regions. The two hip bones articulate with the sacrum at the back to form the pelvic ring; the acetabuli on their outer surfaces articulate with the femoral heads to form the hip joints.

This information is for educational purposes and does not replace diagnosis and treatment. Please consult your doctor about your symptoms.