The Equine Hip Joint: A Guide for Horse Owners

Why the Hip Joint Matters

The hip joint is one of the most important joints in your horse’s body. It connects the hind limb to the pelvis and plays a major role in movement, balance, and power. Every stride your horse takes, whether walking, trotting, cantering, or galloping, relies on a strong, stable hip joint to transfer energy from the hindquarters to the rest of the body.

Compared with joints lower in the leg, the hip is very well protected. This makes injuries less common, but when problems do occur they can have a serious impact on comfort and performance.

What Kind of Joint Is the Hip?

The equine hip (also called the coxofemoral joint) is a ball-and-socket joint. This means a rounded bone fits into a deep socket, allowing smooth movement while maintaining strength and stability.

In horses, the hip is designed much more for stability and power than for wide-ranging movement. This reflects the horse’s natural role as a running and weight‑bearing animal.

Learn more about equine joints by reading The Basics of Joints, and downloading the Joint Anatomy Flashcards.

The Bones That Form the Hip Joint

The Pelvis

The pelvis is made up of three fused bones that together form a deep cup called the acetabulum.

• Ilium: The largest pelvic bone, forming the front part of the hip socket. It provides attachment for large muscles that drive forward movement.

• Ischium: Forms the back part of the socket and supports powerful muscles involved in propulsion.

• Pubis: Completes the lower part of the socket and helps stabilize the pelvis.

  
  

The depth of the acetabulum is one of the main reasons the equine hip is so stable.

The Femur (Thigh Bone)

The femur is the long bone of the upper hind limb.

• Femoral head: The rounded “ball” that fits into the hip socket.

• Femoral neck: A short, thick region connecting the head to the shaft of the bone, built to handle high forces.

• Trochanters: Large bony bumps where strong muscles attach, giving the horse leverage for powerful movement

  
  

  

  
  

Cartilage and the Joint Capsule

The surfaces of the hip joint are covered with smooth cartilage, which allows the bones to glide against each other with very little friction. This cartilage also helps absorb shock.

Surrounding the joint is a thick joint capsule, made of tough connective tissue. This capsule holds the joint together and adds another layer of protection.

The Ligaments That Stabilize the Hip

Ligaments are strong bands of tissue that connect bones and limit excessive movement.

• Ligament of the femoral head: Runs from the femur to the socket and helps keep the joint properly aligned.

• Accessory ligament of the femoral head: Found only in horses and a few related species. This extra ligament greatly limits sideways movement of the hip.

Because of this unique accessory ligament, true hip dislocations are extremely rare in horses.

Joint Fluid and Lubrication

Inside the joint capsule is synovial fluid, a slippery liquid that lubricates the joint and nourishes the cartilage. Healthy synovial fluid is essential for comfortable, efficient movement.

Changes in joint fluid often occur with inflammation or infection, which is why veterinarians may sample it during lameness investigations.

Muscles That Move and Protect the Hip

Large muscle groups surround the hip joint and play a major role in both movement and protection.

• Gluteal muscles: Provide much of the power for pushing off the ground.

• Hamstring muscles: Extend the hip and drive the horse forward.

• Hip flexor muscles: Help lift and advance the hind limb.

• Adductor muscles: Help keep the limb stable and aligned during weight‑bearing.

These muscles act like living support braces, further reducing the risk of injury.

Study the muscles of the horse with the Interactive Horse Muscles Map

Nerves and Blood Supply

Nerves supplying the hip carry pain signals and help coordinate movement. Because the hip lies deep within the body, pain from this joint can be difficult to pinpoint.

Blood vessels around the hip provide oxygen and nutrients to the bone and cartilage, supporting long‑term joint health.

How the Hip Works During Movement

The equine hip does not move freely in all directions. Instead, it works mainly as a powerful hinge, extending and flexing during each stride.

This limited range of motion increases efficiency and reduces wear, but it also means that even small problems in the hip can noticeably affect gait and performance.

Common Hip Problems in Horses

Hip problems are uncommon, but they can include:

• Pelvic fractures

• Femoral head fractures (rare)

• Joint infection in foals

• Degenerative joint disease

Because the joint is deep and surrounded by heavy muscle, diagnosing hip problems can be challenging. Early veterinary assessment is important if hind‑end lameness, asymmetry, or muscle loss is noticed.

What Horse Owners Should Know

• The hip joint is built for strength, not flexibility.

• Serious hip injuries are rare but often significant.

• Hind‑end lameness is not always caused by the hip, but hip disease should be considered when other causes are ruled out.

• Prompt veterinary evaluation improves outcomes.

  
  

Evidence and Understanding

Most of what we know about the equine hip comes from anatomical studies, veterinary imaging, and clinical experience. While the basic structure of the joint is well understood, direct research on how forces act inside the living joint is limited due to its depth and inaccessibility. As a result, some knowledge is based on careful interpretation rather than direct measurement.

Take‑Home Message

The equine hip joint is a deep, stable, and powerful structure designed to support weight and generate movement. Its unique anatomy helps protect it from injury, but when problems do arise they deserve prompt attention. Understanding how the hip works can help horse owners better recognize concerns and appreciate the remarkable design of the equine hind limb.