Dooley Noted: 5/18/2016
The Longissimus Capitis (LCap) is a muscle that is often forgotten about but has huge clinical implications.
LCap is the most superior attachment of the erector spinae’s middle portion to the mastoid process. It shares the mastoid attachment with Splenius Capitis and Sternocleidomastoid (SCM).
LCap travels mostly from transverse processes of vertebrae to other transverse processes, except where it attaches to the skull.
The LCap is covered on its posterior surface with the posterior layer of thoracolumbar fascia (TLF). This connection from skull to lumbar spine helps the cervical spinal musculature fire when the lumbar spine fires.
Also, when the pull is not present from the lumbar spine, the neck can excessively compensate for missing intra-abdominal pressure (IAP) generated by muscles that attach to the lumbar spine or its TLF.
This explains why you use your neck as a secondary set of core muscles, often deemed the extrinsic core.
If they are stabilizing you for others actions, you can’t ask them to mobilize you through all your ranges.
Thus, LCap can create a stiff, overworked neck in cases of low back instability.
Since LCap is deep to Splenius Capitis, the fascia surrounding the muscles blend. This makes capital (head) extension now a multiple muscle compensation for low back stability loss.
This can be easily seen in a toe touch, where the low back has limited stability as its asked to excessively flex for an absence of hip movement.
Lumbar instability shows as a peaking, hyperkyphotic thoracic spine.
It also shows what’s compensating for it, with head extension usually seen on the toe touch of the same patient.
Consider that concentric (shortened) loading of LCap may create a lumbar stability loss lower down in the kinetic chain.
To watch for some helpful correctives for improving this synergistic flexion relationship, follow the link below on dissecting the toe touch.
Also, consider some manual therapy assessment of the LCap to improve synergy in spinal flexion and extension, as well as the proper building of IAP.
As always, it’s your call.
– Dr. Kathy Dooley
For more on the the toe touch and LCap: