05 Dec Kinetic Chain Mobility & Stability
“Executing a proficient golf swing or any athletic action requires certain levels of joint mobility and segmental stability within the kinetic chain. Dysfunctional movement patterns, alterations in swing mechanics, and the increase in the potential for injury exist when limitations are apparent in the mobility and stability components of the body.” – Sports Performance Coach Sean Cochran
Q: Sean, please explain the terms joint mobility and segmental stability.
Joint mobility can be defined as the optimal range of motion of a joint within the body. Dependent upon the structure of the joint the intended range of motion will be different. For example, the hip is considered a ball and socket joint. This type of joint has an intended large range of motion, meaning it can move large degrees in multiple planes of motion. The elbow is classified as a hinge joint. A hinge joint has one plane of motion and can primarily flex and extend.
Stability according to Dr. Greg Rose of the Titleist Performance Institute is defined as the ability of any system to remain unchanged or aligned in the presence of outside forces. In regards to the kinetic chain, we reference stability as segmental stability. Segmental stability is the ability of kinetic chain to maintain specified postural positions and alignment during human movement.
Q: What are the parameters governing both joint mobility and segmental stability?
Joint mobility is a combination of both joint structure and flexibility. As stated above dependent upon the type of joint structure (i.e. ball and socket, hinge) the mobility parameters of the joint will differ. In addition to structure, flexibility plays a role in the determination of joint mobility.
Flexibility according to Michael Clark of the National Academy of Sports Medicine can be defined as the optimal extensibility of all soft tissues surrounding a joint to allow for full range of motion. Soft tissues is a reference the muscular and ligament structures joints within the kinetic chain.
Segmental stability is contingent upon muscular strength and endurance. It is the ability of the muscular system to efficiently execute and control movement patterns. The golf swing for example requires certain parts of the kinetic chain to be moving while additional segments are stationary. In order for the kinetic chain to execute these movement patterns in an efficient manner requires the muscular system to have specified levels of strength and endurance to both maintain postural positions and perform athletic actions.
Q: Understanding both joint mobility and segmental stability what can cause impairments in both of these components?
Joint mobility restrictions are typically a result of a lack of extensibility of the soft tissues surrounding the joint. This results in limited ranges of motion causing dysfunctions within the joint system. To overcome joint limitations, the kinetic chain will typically recruit a different joint in attempt to generate the required range of motion for the athletic action being performed. The problem with such a situation when joints are asked to move through ranges of motion they are not intended to move through injury can easily result due to the fact the joint does not have the intended range of motion it is being asked to move through. Outside of extensibility, changes in the articular surfaces of the joint can result in limitations. For example, a bone spur, chips, or injury can cause changes in the joint causing a decrease in range of motion.
Limitations in segmental stability are typically caused by a lack of strength and endurance in the muscular system. The muscular system is simply not strong enough or does not have the endurance capacities to maintain postural positions and to execute the required movement patterns. In certain situations a muscle or muscles can be “turned off”, meaning the firing patterns of the neural muscular system are not operating properly, and a muscle is basically not “kicking in” when needed to execute the movement pattern.
Q: Knowing this information what joints need to be mobile and what areas of the body need to be stable?
To answer this question we can turn our attention to the Mobility/Stability Pattern of Human Movement Principle. This principle was created by noted physical therapist Gray Cook and strength coach Mike Boyle. The Mobility/Stability Pattern of Human Movement states efficient movement within the kinetic chain occurs in an alternating pattern of mobile joints and stable body segments. If this pattern is altered, dysfunction in movement patterns will occur and compensations in these movement patterns will be the result. Below is a synopsis of the kinetic chain and a joint-by-joint clarification.
Ankle – Mobile, Knee – Stable, Hip – Mobile, Pelvis/Sacral/Lumbar Spine – Stable, Thoracic Spine – Mobile, Scapular/Thoracic – Stable, Cervical – Mobile, Gleno-Humeral – Mobile, Elbow – Stable, Wrist – Mobile.
Remember locomotion is a “feet to fingertips” activity operating in an alternating pattern of a mobile joint followed by a stable body segment throughout the entire kinetic chain. Keep in mind joints such as the elbow and knee are not rod like pieces of iron, but rather these joints are limited in terms of their degrees of motion. For example, the elbow is a hinge joint operating in one plane of motion whereas the hip is a ball and socket joint rotating in 360 degrees of motion. As a result, within the Mobility/Stability Pattern of Human Movement, the elbow is considered a stable joint where the hip is a mobile one.
Q: Recognizing the importance of the Mobility/Stability Pattern of Human Movement if a golfer has limited mobility or segmental stability what do you suggest?
If limitations exist in terms of mobility or segmental stability the goal is to improve these physical dysfunctions. This process is achieved via the implementation of corrective exercises. The corrective exercises will consist of a series of flexibility and joint mobility exercises to improve range of motion. In addition a series of strength training exercises would be implemented to address segmental stability weaknesses within the kinetic chain. Over time the inclusion of these types of exercises will improve the kinetic chain’s mobility and stability parameters thus allowing for improvement in functional movements, golf swing included to occur.
About Performance Coach Sean Cochran: Sean Cochran, one of the most recognized performance coaches in sports today. A career spanning positions with 2 major league baseball organizations, over 10 years on the PGA Tour and work with top professionals including three-time Masters, PGA, and British Open Champion Phil Mickelson, future hall of fame Trevor Hoffman, and Cy Young award winner Jake Peavy provides Sean a proven track record of success. He has been involved in the production of numerous performance videos and authored books including; Performance Golf Fitness, Complete Conditioning for Martial Arts, and Fit to Hit. He has been a presenter of educational seminars for numerous organizations including the world renowned Titleist Performance Institute.