Tightness in your hamstrings and your heel cord -- or Achilles tendon -- can cause major discomfort when you move. Since these two parts are connected by nerves and fasciae, the tightness sensation in one area, such as the heel cord, can affect how tight your hamstrings feel and vice versa. Since tightness in these areas can be caused by different factors, there are several ways to alleviate hamstring and heel cord tightness.
Whether you suffered a hamstring or heel cord injury last year or finished a half-marathon yesterday, you may feel soreness in your hamstrings and lower calves. The soreness stems from inflammation in your muscles and connective tissues that can cause your hamstrings and heel cords to tighten. This is a protective behavior that your nervous system induces to protect your muscles and joints from tearing, says massage therapist Todd Hargrove. Although it's tempting to stretch your tight and sore hamstrings and heel cords, stretching can cause a stretch reflex that causes your muscles and tissues to contract involuntarily to protect themselves from tearing. This can cause your hamstrings and heel cords to feel tighter and less responsive to relaxation.
Perception Can Be Tricky
Sometimes the length of your hamstrings and heel cords are normal, but your brain perceives them to be tight. Although it's not yet known why your nervous system behaves this way, exercise scientists proposed a sensory theory to explain the behavior. A study published in the March 2010 issue of "Physical Therapy" stated that subjects who completed a three- to eight-week stretching program had a modified sensation in their flexibility rather than actual changes to the length of their muscles. Therefore, the tightness sensation may be just in your head rather than the shortening of your hamstrings and heel cords.
Self-myofascial release, or SMR, is a type of self-massage that's used to enhance muscle and connective tissue relaxation. By applying gentle pressure upon the muscle belly or near the muscle attachments with a foam roller, a sensory organ called the Golgi tendon organ is activated, which stimulates the muscle fibers and tissues to lengthen. The National Academy of Sports Medicine recommends that you maintain the compression for 20 to 30 seconds, but the duration can be longer if the tenderness doesn't subside. Since the heel cord can be very tender to pressure, apply pressure to the lower calf instead.
Static stretching, which is holding a stretch for 20 to 30 seconds, may decrease the tightness in your hamstrings and heel cords, but it does little in improving your athletic performance. Dynamic flexibility, which involves moving your joints and muscles repetitively within your full range of motion, should be performed before your training instead of static stretching. In a study published in the April 2012 issue of "Journal of Strength and Conditioning Research," researchers at the University of North Carolina at Chapel Hill found that subjects who performed a dynamic warm-up before performing strength and flexibility tests had a higher improvement in strength and flexibility than those who did standard stretching or no stretching. The latter two groups had no positive or negative changes in strength or flexibility. Sample exercises that work your hamstrings and heel cords together include leg swings, walking lunges, jogging butt kicks and lateral skipping.