Hamstring tightness? Should you be stretching or strengthening?
Corley McBeth, DPT
Many people struggle with hamstring ‘tightness’ despite regular, sometimes daily, stretching. The tightness never seems to go away. Let’s talk about why this is happening and what you can do about it.
The hamstrings are comprised of three muscles: the semimembranosus, semitendinosus and biceps femoris. They are the primary bulk of muscle on the back of the thigh – originating on your ischial tuberosity (or “sits bone”) and running down behind the knee, where they attach on the bones of the lower leg (the tibia and fibula). This means that the hamstrings cross two joints, the hip and the knee. They are the primary flexors of the knee joint (meaning they bend the knee), as well as secondary hip extensors (meaning they help straighten the hip). The hamstrings also assist in providing rotational control at the knee, in addition to pelvic stability due to their anchoring role at the ischial tuberosities. They also play a role in deceleration when they contract eccentrically (meaning they are contracting while lengthening). This serves to slow the rate of knee extension, such as when you are trying to slow down from running to walking.
When we are focusing on stretching a muscle, it is important to differentiate muscle ‘shortness’ from ‘tightness.’ True muscle shortness is a structural issue related to a decrease in the length of the muscle fibers. Muscles become shortened due to immobilization or disuse, most often associated with casts/braces or non-weight bearing status following an injury and/or surgery. When muscles have shortened in this manner, it is called a contracture.
Muscle ‘tightness’ on the other hand, is neurologically driven and is a sensation associated with a muscle remaining in a contracted or tense state. Often the muscle is receiving input telling it to contract because the body is trying to generate stability. The nervous system may be increasing tone in the muscle as a protective response. The sensation of tightness might lead us to believe we need to stretch that muscle; however, providing input that stabilizes rather than stretches will likely be more effective in these situations.
“Muscle ‘tightness,’ on the other hand, is neurologically driven and is a sensation associated with a muscle remaining in a contracted or tense state.”
In many individuals experiencing ‘tight’ hamstrings, the hamstrings may actually be relatively overlengthened for optimal performance of a specific task. To improve postural control at the pelvis and/or knee, the nervous system will send excitatory input telling hamstrings to contract. Without sufficient tension in the hamstrings (force production), the movement strategy for a particular task will be achieved through compensatory strategies impacting the performance of other muscles such as the abdominals, back extensors, hip flexors, etc. For example, consider lifting a heavy object from the floor using a hip bending strategy (i.e. deadlifting). Without sufficient tension from the hamstrings, back extensors will create more compression on the spine. One can debate whether this is good or bad for the back.
“Tight” muscles, despite the fact they are remaining in a relatively contracted state, are not necessarily strong muscles. It may mean strengthening is the best course.
If you experience chronic hamstring ‘tightness,’ or have a history of hamstring strain and/or low back pain it is recommended to seek out a physical therapist for a formal evaluation. Expert advice based upon your specific experience and goals is very effective. An individualized assessment will help to address your mobility, stability, and overall movement patterns, which will increase the effectiveness of your stretching and strengthening routine.
Corley McBeth, DPT