T he hip FLEXORS and
Pilates
“The Psoas is the most important of all postural muscles” -Basmajjian J. 1974
“Psoas exerts a massive compression load on the lower lumbar disks-upon maximum contraction, in an activity such as sit ups, the two psoas muscles can be expected to exert a compression on the L5-S1 disk equal to about 100kg of weight.”
ae Anterior Til t
Iliopsoas
As the above two quotes reveal, the hip flexors-Iliacus and psoas in particular, can have a profound effect on our posture. The pelvic wheel below, Figure 1, illustrates the anterior tilt force of both muscles. The repercussions of such a tilt can include a lumbar lordosis and back pain, a corresponding thoracic kyphosis and hyper extension at C1&2 also. (See Figure 2)
Ere cto rS pin
-Bogduk N.1997. Clinical Anatomy of the Lumbar Spine
Rectus Femoris INNOVATIONS IN PILATES KenyiDesign 2014
In Pilates mat exercises such as the Leg Pull Front, (Figure 3) and Side Kick Kneeling (Figure 4), tight hip flexors will compromise your ability to perform them correctly. As you extend the leg in Leg Pull, or Swing the leg into extension more dynamically in Side Kick Kneeling, your lumbar spine will be pulled into extension because of tightness in the hip flexors. This is often mistaken for abdominal or “core” weakness. However, the hip flexors will vastly over power the capacity of abdominal muscles to hold a “neutral spine” and repeated performance of the mat exercises won’t improve a great deal without some hip flexor stretching.
FIGURE ONE
A worst case scenario would see the low back injured as a result of repeating these mat exercises without lengthening the hip flexors. In addition, recruitment of the Gluteal muscles, often an emphasis in the mat exercises mentioned, will not be particularly successful without reducing tone in the hip flexors. This is because of a reflex known as “reciprocal inhibition.” When one group of muscles are overly tight, their antagonists, or opposing muscles groups, are usually weak and inhibited.
FIGURE TWO