Workout of the Day:
Jerk (Push or Split)
Full-Tilt on Correct Nomenclature
Written by Mike Hom
1. Functional movement generally weds the spine to the pelvis.
2. Dynamics of functional movement come from the hip, primarily through extension.
3. Muted hip function = muted hip power.
Trunk posture can largely be determined by the flexibility of the hip flexors, erectors, glutes, hamstrings, and abs. The basic explanation for each muscle group is the hip flexors and spinal erectors work to anteriorly rotate the pelvis, while hamstrings, glutes, and abs work to posteriorly rotate the pelvis. When there is an imbalance of either the recruitment (strength or otherwise) or flexibility in any of those muscle groups, the result can be posterior pelvic tilt (like a gymnast hollowing out) or anterior pelvic tilt (excessive lordosis). So without further ado, here are some basic causes of both tilts.
– Tight hip flexors
– Tight erectors
– Weak or lax abs
– Weak or lax glutes
– Weak or lax hamstrings
Posterior Tilt -> Leads to loss of lumbar curve, pelvis is tucked under the hips. Characterized by shortening of hip extensors. This can mean there is no full hip extension expressed, or it means there is flexion in the posterior chain.
– Weak or lax hip flexors
– Weak or lax erectors
– Tight abs
– Tight glutes
– Tight hamstrings
Fixing these issues in a client will achieve several things. It helps articulate the 3 joint movements that are loosely discussed in Coach Glassman’s journal, which are the sacroiliac (SI) joint (btw, this joint is essentially where the lumbar curve is articulated), hip joint and knee joint.
We’ve now clarified the two types of tilt that we see in clients. We ideally do not want the pelvis tilted too far forward (anterior) nor do we want it tilted too far back (posterior). We want a neutral spine, effectively locking the pelvis and spine in place, that can aggressively respond and correct itself to the dynamics of any movement we introduce.
For further reading:
Anatomy and Physiology for Jocks, Greg Glassman, August 2003, http://www.crossfit.com/journal/#3856
Common Postural Deficiencies, http://www.exrx.net/ExInfo/Posture.html
Where Have the Lordosi Gone?, Robb Wolf, July 2008, Performance Menu