What is the hip joint?
The hip joint is the articulated connection between the head of the femur – the upper end of the thigh bone (femur) – and the socket (acetabulum) of the hip bone. Like the shoulder joint, it is a ball-and-socket joint that can move about three main axes. In principle, the ranges of motion of the shoulder and hip joints are also about the same. However, since we mainly move by walking or running, these ranges are rarely used.
What is the function of the hip joint?
The hip joint is where the movements of the legs in relation to the pelvis take place, without which running, jumping, sitting, the ballet dancers’ splits, dancing and much more would not be possible. The three main movements are anteversion, retroversion and abduction:
In anteversion, the thigh is raised, so there is flexion in the hip. With the knee bent, the leg can be raised by up to 140 degrees.
In abduction, the leg is spread laterally to a maximum of about 45 degrees. If the leg is brought back towards the body from this abduction position (adduction) and at the same time lifted forwards and rotated slightly outwards, then it is possible to move this leg beyond the midline to the opposite side. Both sitting and standing, we can then cross the legs.
Where is the hip joint located?
The hip joint is located at the anterior lower arch of the pelvic ring. It consists of the socket of the hip bone and the femoral head of the thigh.
What problems can the hip joint cause?
A common type of fracture in older people, whose bones are decalcified and thus weakened by osteoporosis, is the femoral neck fracture (neck of femur fracture): In this case, the neck of the thigh bone breaks near the hip joint.
Coxitis fugax (“hip flare”) is also a non-infectious inflammation of the hip joint that can occur in four- to ten-year-old children, usually after a previous respiratory or gastrointestinal tract infection.
Hip dysplasia is a congenital or acquired malformation of the acetabulum. In this case, the head of the femur does not find a stable hold in the acetabulum and can pop out (hip joint or hip luxation).
