Low back pain (LBP) is a common problem for runners and is often a reason people leave the sport all together. While numerous contributing factors can lead to LBP, flexibility is a major issue for runners. It is important to stretch short muscles that affect running efficiency and can add abnormal stress through the low back. Stiffness is not the same thing as shortness. Stiffness is the ability of the muscle to transfer force efficiently and is a sign of a good runner. Shortness is a reference to the length of the muscle resulting in a loss of both leverage and normal movement patterns of the body. We will focus on the three most common short muscles that lead to LBP.
Here is a quick note on the timing, frequency, intensity, and duration of stretching to avoid injury. Pre-exercise stretching should be dynamic, which means short duration, 1-2 seconds and higher number of repetitions, 8-15. The goal is to prep the body for the activity by increasing circulation and neuromuscular firing of the muscles. Static stretching is best performed after exercise, once the muscle is warmed, and should be a sustained stretch of 30-60 seconds. The goal is to make a change in muscle length. It is appropriate for short muscles that are negatively affecting running efficiency but should not be done prior to exercise due to risk of injury. The appropriate intensity should be a moderate amount of discomfort while still being able to relax enough to not guard the stretch.