What Is the Biomechanics of the Hip?

The biomechanics of the hip refers to the mechanical motions of that specific anatomical joint. The hip consists of more than one bone, specifically the illium, the ischium, and the pubis. As life progresses, these bones fuse together in a fashion that makes them more uniform with time. The biomechanics of the hip is concerned with movements related to this structure.

The biomechanics of the hip is useful to study for a number reasons. Learning more about the motions associated with particular body parts can help diagnose and treat illness and injury. It can also help improve movement in a person struggling to walk to the elite athlete looking for an edge on the competition.

The manner in which biomechanics research is conducted is similar to other scientific fields of study. This process begins with a problem, for example, a person who is unable to walk straight. Researchers gather information pertaining to this problem and test hypotheses. This may consist of the hypothetical reason that the hip cannot rotate laterally, and the gathered information may consist of film examining this person's gait. This method is continuously repeated until researchers can apply new concepts and information to solving movement conundrums.

The movements of the hip can be described using a set of anatomical terms. These terms are flexion, extension, adduction, and abduction in addition to medial rotation and lateral rotation. When muscles contract, they pull on various parts of the bone, resulting in movement. Different muscles are connected to varied regions of bone, which is why certain muscles can only have specific movements. In the case of the hip, there are many muscles involved in creating the ROM, or range of motion.

Understanding each movement involved in the biomechanics of the hip is like knowing what each part of a motor does. Extension refers to the act of increasing the angle of the back part of the knee, or the straightening of a bent leg. The opposite of extension is the decreasing of this angle, known as flexion.

Adduction and abduction also refer to opposing movements. A common way to remember them is through their prefixes. The "add" in adduction can be thought of as "adding" the leg to the body. When a person does the splits, adduction returns the legs to a neutral position. Abduction moves the legs from this neutral point to a split position.

Rotation refers to movement about a fixed axis. This axis in the context of the biomechanics of the hip is usually the femur. Medial rotation refers to the internal movement toward the body, generally forcing the ankle to compensate by moving laterally. Lateral rotation, consequently, is the opposite of its medial counterpart.