If you’ve ever had a bout of low back pain, you know it affects all kinds of movements. Suddenly, you can’t get out of bed so easily. You walk more slowly. And turning takes actual thought and planning.
Finding ways to measure and treat loss of motion is the focus of recent research. In the past, trunk movement in people with low back pain was studied by measuring range of motion and the amount of muscle force used. However, new technology developed in the last 10 years has made it possible to go beyond these simple measures. Looking at other areas of body movement during walking will help physical therapists design more specific treatment for back pain patients.
As might be expected, people with low back pain show decreases in walking speed, step length, and how long they can walk. Moving forward requires the pelvis and trunk to rotate in balance with each other. Back pain can change the timing and coordination of these movements. This slows a person down considerably.
A recent study using a treadmill and advanced recording technology has given some new information about walking. At slower walking speeds, the pelvis and trunk coordinate together in a pattern that is called in-phase coordination. This is true for people with or without back pain. But as the speed of walking increases, people without back pain switch to an out-of-phase pattern called anti-phase coordination.
Interestingly, patients with back pain try to keep the in-phase pattern as they increase walking speed. This is probably because they are using muscles to lock the trunk and pelvis in place. When a person is in pain, the muscles tend to contract and hold. This is called protective guarding. Physical therapists can use this information to plan exercises that will return movement patterns to normal at all speeds.