 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

 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

 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

 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

   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

 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

  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

 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

  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

 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

 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

 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

 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

 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

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

 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

 Dynamic balance test include functional reach test, timed agility, figure 8’s, carioca, or hop test › Ability to maintain upright posture while moving

 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

 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

 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

 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

 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

 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

 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 (taps or movement)  Overload or stress somatosensory system

 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

 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

  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