Regaining Postural Stability and Balance

1. Regaining Postural Stability and Balance Rehabilitation Techniques for Sports Medicine and Athletic Training William E. Prentice

2. Introduction • Muscular weakness, proprioceptive deficits, and range of motion deficits may challenge a persons ability to maintain their center of gravity (COG) • May lead to loss of balance • Balance is the single most important element dictating movement strategies • Dynamic process involving multiple neurological pathways

3. Introduction • Joint position sense , proprioception, and kinesthesia are vital to all athletic performance requiring balance • Ability to balance and maintain postural stability is essential to an athlete who is acquiring or reacquiring complex motor skills

4. Postural control system • Complex process involving sensory and motor components • Most daily activities such as, walking, climbing stairs, throwing a ball, require static foot placement with controlled balance shifts • Balance should be considered both a static and dynamic process

5. Postural control system • Impaired balance is a result of one or a combination of two reasons • Position of COG relative to base of support is not accurately sensed • Automatic movements required to bring COG to a balanced position are not timely or effectively coordinated

6. Postural control system • Position of the body in relation to gravity and its surroundings is sensed by combining visual, vestibular and somatosensory (proprioceptive)inputs • Balanced movements also involve motions of the ankle, knee, and hip joints • Primary mechanisms for controlling balance occur in joints of the lower extremity • Postural control system operates as a feedback control circuit between brain and the musculoskeletal system

7. Somatosensory input • Mechanoreceptors transmit messages to brain through sensory nerves in spinal cord • Helps to control proprioception or body/joint position • Provides information concerning the orientation of body parts to one another and to the support surface

8. Balance & Closed Kinetic Chain • Balance is the process of maintaining the COG within the body's base of support • Within kinetic chain each moving segment transmits forces to every other segment along chain • Maintaining equilibrium or balance is associated with injuries along the closed kinetic chain • Injuries to any one of the joints or corresponding muscles along kinetic chain can result in loss of appropriate feedback for maintaining balance

9. Control of Balance • Human body is a tall structure on a relatively small base • COG is quite high, just above pelvis • Somatosensory input is preferred sense for balance • i.e. : feet in contact with support surface and detection of joint movement

10. Control of Balance • Visual input • Measures orientation of the eyes and head in relation to surrounding objects • If eyes are closed balance becomes more difficult • Vestibular input • Sensory system that is leading contributor to response to movement and sense of balance • Sends signals, primarily to neural structures that control our eye movement, and to muscles that keep us upright

11. Proprioception & Kinesthesia • Proprioception: ability to determine the position of a joint in space • Kinesthesia: ability to detect movement • Mediated by mechanoreceptors found in muscle and joints and by cutaneous, visual and vestibular input

12. Proprioception & Kinesthesia • Joint mechanoreceptors • Found in ligaments, capsules, menisci, labra and fat pads • Sensitive to change in shape of joint structures and rate and direction of movement of joint • Most active at end ranges of motion

13. Proprioception & Kinesthesia • Muscle mechanoreceptors • Found in muscles and tendons • Muscle spindles and Golgi Tendon Organs • Muscle spindles sensitive to changes in length of muscle • Golgi tendon organs sensitive to changes in tension

14. Assessment of Balance • Subjective Assessments: Romberg's & Balance Error Scoring System (BESS) • Romberg's test • Feet together, arms out to side, and eyes closed • Positive test: sway or fall to one side • indicates loss of proprioception

15. Assessment of Balance • Balance Error Scoring System (BESS) • 3 stances: double , single, and tandem • Completed 2 x each: Once on firm surface and once on unstable surface (Foam pad) • Total of 6 trials • Hands on iliac crest and eyes closed • In SL ex. Non stance leg held at 20-30 degrees hip flexion and 40 to 50 degrees of knee flexion

16. Assessment of Balance BESS Assessment Continued • 20 second test begins when eyes close • Single leg stance on non-dominant leg (NDL) and NDL is in the rear for tandem stance • Upon losing balance athlete returns to testing position as quickly as possible

17. Assessment of Balance • Balance Error Scoring System (BESS) • Scoring • 1 point added for each error that occurs • Hands lifted off iliac crest • Opening eyes • Step, stumble or fall • Moving hip into > 30 degrees of flexion or Abduction • Lifting forefoot or heel • Remaining out of testing position >5 seconds • Higher scores represent poor balance

18. Assessment of Balance • Dynamic balance test include functional reach test, timed agility, figure 8’s, carioca, or hop test • Ability to maintain upright posture while moving

19. Assessment of Balance • Advancements in technology have provided equipment to quantitatively assess and train dynamic balance • Mostly computer -interfaced force- plate technology • Potential to assess possible abnormalities that might be associated with injury and help create appropriate training programs

20. Injury & Balance • Stretched or damaged ligaments may fail to provide adequate neural feedback • May contribute to decreased proprioceptive mechanisms, and thus decreased balance • Increased postural sway and balance instability contributed to neurological factors and biomechanical factors after injury

21. Balance Training • Rehab program, especially for lower extremities must include exercises to improve balance and postural equilibrium • Any injury can cause disruption at some point between COG and base of support • If neglected can lead to reinjury, decreased performance, or other injuries

22. Balance Training • 5 general rules • Safe, yet challenging • Stress multiple planes of motion • Incorporate multisensory approach • Begin with static, bilateral stable surface and progress to dynamic, unilateral, and unstable surface • Progress toward sport specific activity

23. Balance Training • Balance Exercises • Static: COG maintained over fixed base of support while on stable surface • Semi-dynamic: • Maintain COG over fixed base on moving support or unstable surface • Person transfers their COG over a fixed base of support on stable surface through range and/or directions

24. Balance Training • Balance Exercises • Dynamic: maintenance of COG over moving base of support • Usually stable surface, but could be unstable • Base of support always changing position so COG is forced adjust with each movement • Functional • Same as dynamic, but add sport specific tasks

25. Balance Training • Phase I • Can be initiated once athlete can bear weight on the extremity • Static, non ballistic exercise • Hard firm surface • Bilateral to unilateral (double leg to single leg) • Eyes opened to eyes closed • Progress to unstable surface, perturbations (tapsor movement) • Overload or stress somatosensory system

26. Balance Training • Phase II • Transition of static to semi-dynamic & dynamic ex. • Important for running, jumping, and cutting athletes • Progress only if sufficient healing has occurred and ROM, muscle strength and endurance is adequate • Balance through movement • Controlled hip and knee flexion and smooth return to stabilization position • Progress to added resistance and more difficult movement patterns

27. Balance Training • Phase III • Dynamic & Functional exercises • Slow speed to fast speed • Low force to high force • Controlled to uncontrolled activities • Jumping or hopping activities • Bilateral to unilateral • Single plane to multi-plane • Exercises may differ between athletes • Be sport specific

28. Conclusion • Balance and postural stability critical to athletic performance and injury prevention • A rehabilitation program must include functional exercises that incorporate balance and proprioceptive training • Prepare athlete for return to activity • Failure address balance problems may predispose athlete to reinjury and injury • Use imagination, be creative • Use sport specific tasks