Definition/Introduction

Williams back exercises, also known as Williams flexion or lumbar exercises, are exercises for people with low back pain. Williams back exercises are recommended for people with low back pain to help improve lumbar flexion and strengthen the gluteal and abdominal muscles. The exercises were first developed for men younger than 50 years of age and women younger than age 40 who had moderate to severe lumbar lordosis and whose plain radiological films revealed diminished disc space between the lumbar segments L1-S1. Also, these patients had chronic low back pain that was mild to moderate in nature.

These exercises were introduced to teach the patient how to avoid lumbar extension, which worsens low back pain. Williams's back exercises are a non-surgical option for people to improve low back pain. These exercises came into being for people who do not want to undergo low back surgery. In the last two decades, Williams back exercises have seen a broad application for people with various types of low back pain, even in the absence of a formal diagnosis. Also, both physicians and physical therapists have developed many variations of these exercises.

In comparison, the McKenzie method emphasized motion with increased lumbar extension. The McKenzie extension exercises and William flexion exercises were both founded in the 1930s. The Mckenzie method is also known as the Mechanical Diagnosis and Therapy method (MDT); the goal of the McKenzie exercises to retain lumbar lordosis. Furthermore, full motion of the spine is recommended with a combination of flexion and extension exercises. Limited studies have been done showing the efficacy of the Williams or McKenzie exercises compared to placebo or versus each other in direct comparison.[1] The Mckenzie method has been shown to improve motion in muscle energy techniques for osteopathic manipulative therapy. No such studies have taken place for the Williams exercises.[2]

There are different classifications or syndromes for the origin of back pain in the McKenzie method. Postural, dysfunction, and derangement syndromes are the most common. Treatments are often based on the position of ease, which reduces the patient's back pain.[3] Thus if the patient's pain is relieved in flexion, then flexion exercises will be performed. Multiple studies have shown the McKenzie method to be superior to other exercise regimens for subacute and chronic low back pain. However, the limited difference has been seen in the acute setting.[4][5]

A series of exercises seen for Williams back pain exercises include pelvic tilt, single knee to chest motion, double knee to chest motion, partial sit up, hamstring stretch, hip flexor stretch, and squat. The purpose of Williams back pain exercises is to reduce pain and restore function. Furthermore, the prevention of future injury and the development of chronic pain are critical. In an eight week study that compared Williams back pain exercises to a no-treatment control, the experimental group was found to have decreased back pain, as well as an increase in the flexibility of their hamstring muscles, hip flexors, lumbar extensor muscles. They were also found to have increased abdominal muscle strength.[6]

Issues of Concern

The main issue of concern is whether the William back exercises were superior or inferior to the McKenzie protocol. Researchers have compared the Williams and McKenzie protocols for back pain. Decreasing pain and return of lumbar motion were the variables examined. In the comparison of the two groups, patients who underwent the McKenzie protocol improved function to a significantly greater extent than patients in the Williams protocol group, as well as achieved this results in a significantly decreased period. EMG activity at four lumbar vertebrae was examined in patients performing posterior and anterior pelvic tilt exercises of the Williams protocol. The results showed the positions of pelvic tilt, curl up, knees to chest, and hamstring stretch, when completed with posterior tilt, minimized the electromyographic activity in both the lumbar and sacral regions. Furthermore, the use of anterior tilt positions should be avoided to minimize electromyographic activity in the lumbar and sacral regions. Lastly, the electromyographic activity the four lumbar vertebral levels respond independently of each other while the performance of Williams' flexion exercises.[7]

Generally speaking, patients with acute mechanical low back pain do not get referred to physical therapy or a home exercise program, but select populations at increased risk for developing chronic back pain could benefit.[8] Some studies have shown there to be modest efficacy to starting exercise therapy for back pain less than four weeks in duration, while multiple systematic reviews have not shown them to be superior to conservative therapy. 

Although some studies do prove that there is a significant efficacy of exercise therapy in selected cases of acute low back pain (less than four weeks).[9][10] However, systematic reviews have not demonstrated a treatment benefit of exercise therapy compared with conservative management.[11] Separately the evidence does support the use of exercise therapy for patients with subacute and chronic low back pain.[9][10][11]

Clinical Significance

Before the availability of more advanced treatment modalities for low back pain, the Williams exercises were the standard of care for this problem. The exercises can be performed in the supine position on any flat surface. The first maneuver of importance is to grab the legs and pull the knees to the chest and hold them for several seconds. Williams felt that this helped open the intervertebral foramen, stretched the ligaments, and distracted the apophyseal joints. 

Williams originally designed these exercises for chronic low back pain secondary to low-grade lumbar disc disease seen on X-ray. The theory was that when pressure is placed on the posterior aspect of the lumbar vertebral with extension, disc herniation can occur. In theory, this is due to increased lumbar lordosis; lumbar lordosis would decrease by limiting the pressure placed on the posterior aspect of the lumbar vertebra. The decrease in pressure would improve by improving the flexion of the vertebral disc, leading to decreased disc herniation, thus reducing the incidence of chronic low back pain. The exercises proposed to open the intervertebral foramen to provide additional lumbar stability. The McKenzie exercises have their basis on the belief that humans are constantly in a flexed position; this, in turn, causes the nucleus of the lumbar disc to move posteriorly. The posterior motion of the lumbar disc then causes back pain.

When patients perform the exercises regularly, they reduce pain, improve the stability of the lower pelvis, and increase the range of motion. The seven variations of Williams’s exercises include: 1) the pelvic tilt, 2) the single knee to chest, 3) double knee to chest, 4) partial sit-up, 5) hamstring stretch, 6) hip flexor stretch, and 7) squatting.

The Williams back pain exercises are repeatable as well as done for various lengths of time. The recommended duration for the exercise is every day for 10 to 20 minutes. Exercises are done with the patient lying supine on a flat surface and completed at home. Then the patient would flex their legs by pulling their knees to their chest and holding this position. The patient would relax and repeat the motion. An example of the various exercises appears below.

• The posterior pelvic tilt position is performed with the patient lying on their back with their hands at their side and their knees bent. The patient is then told to tighten the muscles of their abdomen, as well as their buttock muscles, flattening their back against the floor.
• The single knee to chest motion is done with the patient lying on a table or bed. They are then instructed to let a leg fall off the table or bed, bend their other leg and wrap their hands around the bent knee, and pull the bent leg toward their chest.
• The double knee to chest stretch is also done with the patient lying on their back. The patient is instructed to bring both their knees, one at a time, to their chest. With their hands held together, the patient pulls their knees towards their chest and curls their head forward. While performing the motion, the patient is instructed to keep their knees together and to have their shoulders flat on the floor. The patient then lowers one leg at a time.
• The lumbar flexion position with rotation is completed with the patient lying on their back with their hands at their sides and their knees bent. The patient is then instructed to rotate their knees towards the direction of pain.
• The seated lumbar flexion exercise starts with the patient sitting upright in a chair. The patient is urged to slowly bend forward until they feel the tension in their back. In contrast, the standing lumbar flexion exercise starts with the patient standing upright with their feet spread shoulder-width apart. The patient slowly bends forward, sliding their hands down to their legs until they feel the tension in their back.
• The partial sit-up exercise is completed with the patient lying on their back with their hands at their sides and their knees bent. The patient is instructed to use their abdominal muscles to raise their upper back off the floor while exhaling. The patient is supposed to rise only enough to get their shoulder blades off the floor. Furthermore, the patient is not supposed to thrust themselves off the floor or to lift their heads with their arms. While performing this motion, the patient is supposed to keep their knees bent and their feet flat on the floor. The patient should feel the muscle contraction only in their abdominal muscles. The patient is then instructed to gently lower their upper body in a smooth and relaxed motion.
• The partial diagonal sit-up is completed with the patient lying on their back with their hands at their sides and their knees bent. The patient is instructed to use their abdominal muscles to raise their upper back off the floor while exhaling. The patient raises their upper body off the floor with one shoulder higher than the other. The patient is not supposed to thrust themselves off the floor or to lift their heads with their arms but to keep their knees bent and their feet flat on the floor. The patient should feel the contraction only in their abdominal muscles. This motion is supposed to move smooth and relaxed while gentle lowing their upper body.

Mechanical back pain is one of the most common complaints seen in a primary care clinic. It often resolves with conservative management and time. Home exercise programs such as the William flexion exercises and the McKenzie extension exercises are two of the most common home exercises used. The William flexion exercises are designed to improve flexion of the lumbar vertebra while limiting lumbar extension. Performing these exercises, we aim to strengthen the gluteus and abdominal muscles. These exercises have been recommended for patients with a variety of low back pain complaints since the 1930s.

Most of the evidence is either level III or IV. Few recent studies have been completed on the Williams back exercises despite being the standard of care previously.  Health care professionals, which include physicians, therapists, and nurses, must have active conversations regarding home exercise programs with patients experiencing mechanical back pain. Home exercise programs can be considered part of the standard of care for mechanical back pain, along with other conservative treatment options.