I posted a thread yesterday about the Importance of Flexibility. I began talking with a guy that is currently seeing a chiropractor for lower back pain due to his SI Joint, which is part of the pelvic girdle. I felt that the topic of our discussion was worthy of its own thread, and I wanted to share it.

Essentially, in terms of injury prevention, stretching plays a role of not only increasing flexibility in the target muscles but also in the secondary muscles that can work in tandem. The lumbar region of the back is an integral area in that it consists of multiple joints and bones to provide for muscular points of origin and insertion. As a result, attention should be paid to this area as a whole rather than individually.

Of particular concern should be flexibility in the posterior thigh (hams and glutes) and the lower back. A lack of flexibility in these areas increases the risk of chronic lower back pain.

muscles are designed so that they allow movement of bones across joints. this is accomplished thru the shortening action provided by the contractions. generally speaking, most muscles have two points on them: point of origin and point of insertion. these points are always on different bones that are connected by a joint. when the muscle contracts, the joint moves to allow the two points and the attached bones to come closer together.

when flexibility is lacking, the muscles will remain in a somewhat tensed state, which increases the stress of secondary muscles near the origin or insertion points. the hamstrings are actually a series of muscles, each with their individual origin and insertion points. three of the muscles making up the hamstrings (Biceps Femoris, Semitendinosus, & Semimembranosus) all originate on the Ishium, which is part of the pelvic girdle. The gluteus maimus has the following origin and insertion points:

Origin

Ilium Crest (Posterior)
Sacrum (Posterior)
Fascia of the Lumbar Area

Insertion

Femur
Gluteal Line
Tibia

This translates to each origin point also provides an insertion point for other muscles not mentioned here, like the muscles making up the lumbar region. If flexibility is lacking in the hams and/or glutes, unneccessary stress will be placed on the secondary muscles that are inserted on these bones, which will cause these muscles to tense up as well and become weak. because the muscles of say the lumbar region are not very strong as it is, it is important to incorporate a holistic flexibility program to safeguard them from injuries.