The forgotten muscle in performance and injury prevention.
It's common to see athletes of all ages and abilities engaged in prolonged, static stretching of a muscle or muscle group. Imagine the classic scene of a jogger stopping at a park bench for a quick hamstring stretch. From competitive sport to physical education classes to yoga, passive static stretching is the norm. In fact, hamstring stretches are one of the mainstay stretches used by everyone. However, this may not be the path to performance and injury prevention that many believe it to be. Increased mobility, pain-free function, and injury prevention may actually require that we flip the relationship between strength and flexibility in the lower extremity. It makes more sense to stretch our quadriceps instead of strengthening them, and strengthen our hamstrings instead of stretching them.
Appreciating the interconnectedness of tissues in the human body helps when we consider how and why we stretch. A prime example is the lumbo-pelvic-hip complex. Essentially, the quadriceps and the hamstrings meet at the bones of the pelvis, creating a fulcrum. There is a basic relationship between the anterior thigh (quadriceps and hip flexors) and posterior thigh (hamstrings and glutes). That relationship influences the muscles of the abdominal wall and low back via the pelvis. This is possible because they share a similar front to back of the body relationship through the pelvis.
As this relates to the muscles of the thigh, the quadriceps are typically in a shortened position. At the same time, the hamstrings are elongated. To understand this, picture your position when sitting in your favorite easy chair. The same holds true for most of our daily activity like walking or standing. Because of this, the hamstrings are constantly at a disadvantage. Static stretching of the hamstrings only makes the situation worse. The already chronically stretched hamstring gives up even more ground to the quadriceps in relation to the pelvic fulcrum and becomes weaker.
Quadriceps & Hamstring Imbalances
Research suggests the ratio of hamstring to quadriceps strength should be roughly 0.6. This means that the hamstrings possesses 60% of the strength of the quadriceps. In athletic populations, this strength ratio is closer to 1.0, or equal, for purposes of injury prevention. Static stretching weakens force production, reduces strength endurance, and diminishes sprint performance. Because of this, we may be putting ourselves at a mechanical disadvantage by habitually stretching our hamstrings. This could potentially result in causing injury instead of preventing injury.
So, is it better to skip stretching?
As a rule, its still important to stretch. But, it's all about timing - post-exercise v. pre-exercise, and type - dynamic v. static. When stretching, focus on the results you want. Ask yourself what area of your body you are mobilizing, and what mechanical changes are occurring as a result. For example, if we stretch the quadriceps with an emphasis on movement, it helps reduce tension in the hamstrings. Therefore, our muscles are more ready for training and competition. Another key step is the addition of high quality strength and conditioning focused on the posterior muscles. Examples include dead lifts and kettle bell swings. So keep stretching, training, and playing. At the same time, be mindful that sometimes our attempts at preventing injury aren’t always what they seem.
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