Williams flexion exercises - also called Williams lumbar flexion exercises, Lumbar flexsion exercises or simply Williams exercises - are a set or system of related physical exercises intended to enhance lumbar flexion, avoid lumbar extension and strengthen the abdominal and gluteal musculature in an effort to manage low back pain non surgically. The system was first devised in 1937 by Dr. Paul C Williams (1900-1978) then a Dallas orthopedic surgeon.
Williams believed that the basic cause of all pain is the stress induced on the intervertebral disc by poor posture. He theorized that the lordotic lumbar spine placed inordinate train on the posterior elements of the intervertebral disc and caused its premature dysfunction. He was concerned bout he lack of flexion in daily activities in the accumulation of extension forces that hurt the disc.
The goals of these exercises are to open the intravertebral foramina and stretch the back extensors, hip flexors and facets; to strengthen the abdominal and gluteal muscles; and to mobilize the lumbosacral junctions.
Williams believed that the back pain was the result of human evolution in movement from a quadruped to an upright position, proposing that the standing position was the cause of back pain because it placed the low back in a lordotic curve. Williams advocated seven exercises to minimize the lumbar curve: Pelvic tilt exercises, partial situps, single knee to chest and bilateral knee to chest, hamstring stretching, standing lunges, seated trunk flexion, and full squats.