What is the definition of segmental stability, as mentioned in “Scientific Balance Training - Part 1" by Paul Chek?
With regard to the musculoskeletal system, stability can be broken down into the following functional components:
Gross Stability: Stability created by musculo-fascial systems that cross multiple joints. The latissimus dorsi, rectus abdominis and psoas are examples of muscles offering gross stability.
Segmental Stability: Muscles such as the rotatories, multifidus or rotator cuff muscles act locally, providing segmental stability.
Static Stability: When one views posture or the ability to hold a given position as a function, we are looking at static stability. Hair dressers and dentists must hold their arms in static positions, often for extended periods of time. Mechanics must bend statically over the fender of a car to make adjustments. The golfer must address the ball, which is a static component of the golf swing. In most instances, static stability provides the working foundation for other dynamic processes or functions.
Dynamic Stability: The ability to maintain an optimal instantaneous axis of rotation in any or all working joints may be termed dynamic stability. Failure to produce dynamic stability leads to instability, which can occur globally and/or locally.