01/31/2022
Forgotten Muscles - Multifidus
"There is evidence that the multifidus muscle is continuously active in upright postures, compared with relaxed recumbent positions. Along with the lumbar longissimus and iliocostalis, the multifidus provides antigravity support to the spine with almost continuous activity. In fact, the multifidus is probably active in all anti-gravity activity.
‘Postural muscles, structurally adapted to resist prolonged gravitational stress, generally resist fatigue. When overly stressed, however, these same postural muscles become irritable, tight, shortened. The antagonists to these postural muscles (most usually phasic muscles) demonstrate inhibitory characteristics described as ‘pseudoparesis’ (a functional, non-organic, weakness) or ‘myofascial trigger points with weakness’ when they are stressed.’
The multifidus muscle must always be considered when saddle fitting, especially with regards to the gullet channel of the saddle. When measuring the gullet width, we prefer to go with the narrowest measurement as it indicates that the saddle, in whatever area (typically closer to the cantle) is at higher risk of coming in contact with the spinal nerves and multifidus which can cause instability, and thus overload the longissimus in having to stabilize the back. The harmonious function of these muscles together are what prevent soreness in the back and premature fatigue.
All saddles should have a gullet width no less than 4" all the way through, with it sitting parallel to the spine equidistance on either side. Any deviation will cause the panel to cross over and make contact during locomotion.
