From the Experts: Hip Issues: Hip Issues Introduction

Wear & Tear and Asymmetry
Save for acute injuries, knee and hip pain are most commonly caused by wear and tear, which can be further irritated by the subtlest asymmetry. Imbalances in the hips can disturb alignment of knees, and vice versa. – Marla Apt
Tight Adductors, Weak Abductors
In most of us, the groin muscles (adductors) tend to be tight, pulling the heads of the thighbones into the sockets. The thighbones are meant to be centered in the socket and stabilized by the abductors, which oppose the groin muscles. But when these abductors are weak and stressed, as they often are, the resulting imbalance causes grinding and deterioration in the joints. – Doug Keller
Ligament Tears & Osteoporosis
The most common problems with hips are tears to the ligaments and the labrum, and osteoporosis. – Bernie Clark
Functional Integration Issues
It is important to recognize that most of the conditions affecting the sacrum, hips, and knees reflect a poor functional integration between the lumbo-sacral spine, the pelvis, and the attached legs. The methodology for working with these conditions, therefore, involves working to adjust the functional relationship between these areas. – Gary Kraftsow