The problem is that these muscles aren't designed to be prime movers—they're designed to support the action of the glutes. Inability of activating the glutes can result in low back pain (low back muscles compensating), hamstring strains (overacting hamstrings), hip pain (resulting from hamstring-dominant hip extension) and knee pain (poor glute medius strength).
Gait analysis studies in the elderly show that they typically have a shortened step length. Whether that is a result of tight hip flexors or due to reduced balance, the propensity to walk with shorter steps will itself lead to tightness in hip flexors and anterior joint structures. Hip stretches may be a relatively easy preventative strategy for the elderly with gait abnormalities and may help to prevent falls.
Start in a runner’s lunge, right leg forward with knee over ankle and left knee on ground with top of your foot flat on the mat. Slowly lift torso and rest hands lightly on right thigh. Lean hips forward slightly, keeping right knee behind toes, and feel the stretch in the left hip flexor. Hold here, or for a deeper stretch, raise arms overhead, biceps by ears. Hold for at least 30 seconds, then repeat on opposite side.
If certain activities or overuse are causing hip pain, stop those that aggravate the discomfort and talk to your doctor. Excess weight can put pressure on the hip joint, so losing the pounds can provide relief and help you avoid further problems. Some causes of hip pain, such as fractures or hernias, may need surgical repairs. If your hip pain persists, talk to your doctor about the possible causes and treatments.
Grade III (severe): A complete tear in your muscle that causes severe pain and swelling and you can't bear weight on that leg, making it difficult to walk. You've also lost more than 50 percent of your muscle function. These injuries are less common and may need surgery to repair the torn muscle. They can take several months or more to completely heal.