(c) 2004 The McGraw-Hill Companies, Inc. All rights reserved Chapter 8: Regaining Stability and Balance Jenna Doherty-Restrepo, MS, ATC, LAT Rehabilitation Techniques in Athletic Training

(c) 2004 The McGraw-Hill Companies, Inc. All rights reserved Factors that impact balance Factors that impact balance –Muscular weakness –Proprioceptive deficits –ROM deficits Balance is critical in dictating movement strategies within the closed kinetic chain Balance is critical in dictating movement strategies within the closed kinetic chain Vital component in rehabilitation Vital component in rehabilitation –Proprioception and Kinesthesia Balance

(c) 2004 The McGraw-Hill Companies, Inc. All rights reserved Postural Control System Components Components –Sensory detection of body motions (Feed-forward) –Execution of musculoskeletal responses (Feedback) Balance is a static and dynamic process Balance is a static and dynamic process Disrupted balance occurs due to two factors Disrupted balance occurs due to two factors –Position of CoG relative to base of support is not accurately sensed –Automatic movements required to maintain the CoG are not timely or effective

(c) 2004 The McGraw-Hill Companies, Inc. All rights reserved

Body position in relation to gravity is sensed by Body position in relation to gravity is sensed by –Visual –Vestibular –Somatosensory inputs Balance movements involve a number of joints Balance movements involve a number of joints –Ankle –Knee –Hip –Coordinated movement along kinetic chain

(c) 2004 The McGraw-Hill Companies, Inc. All rights reserved Control of Balance Postural control relies on feedback Postural control relies on feedback CNS involvement CNS involvement –Sensory organization Determines timing, direction and amplitude of correction based on input Determines timing, direction and amplitude of correction based on input System relies on one sense at a time for orientation System relies on one sense at a time for orientation –Muscle coordination Collection of processes that determine temporal sequencing and distribution of contractile activity Collection of processes that determine temporal sequencing and distribution of contractile activity Balance deficiencies Balance deficiencies –Inappropriate interaction among 3 sensory inputs Patient that is dependent on one system may be presented with inter-sensory conflict Patient that is dependent on one system may be presented with inter-sensory conflict

(c) 2004 The McGraw-Hill Companies, Inc. All rights reserved Sensory Input Sensory Input –Somatosensory Provides information concerning relative position of body parts to support surface and each other Provides information concerning relative position of body parts to support surface and each other –Vision Measures orientation of eyes and head in relation to surrounding objects Measures orientation of eyes and head in relation to surrounding objects Role in maintenance of balance Role in maintenance of balance –Vestibular Provides information dealing with gravitational, linear, and angular accelerations of the head with respect to inertial space Provides information dealing with gravitational, linear, and angular accelerations of the head with respect to inertial space Minor role when visual and somatosensory systems are operating correctly Minor role when visual and somatosensory systems are operating correctly

(c) 2004 The McGraw-Hill Companies, Inc. All rights reserved Proprioception/Kinesthesia Specialized variation of the sensory modality of touch, encompassing joint sense and position Specialized variation of the sensory modality of touch, encompassing joint sense and position Process Process –Input is received from mechanoreceptors –Stretch reflex triggers activation of muscles about a joint due to perturbation Results in muscle response to compensate for imbalance and postural sway Results in muscle response to compensate for imbalance and postural sway –Muscle spindles sense stretch in agonist, relay information afferently to spinal cord –Information is sent back to fire muscle to maintain postural control

(c) 2004 The McGraw-Hill Companies, Inc. All rights reserved Closed Kinetic Chain Balance Balance –Process of maintaining body’s CoG within base of support –CoG rests slightly above the pelvis Kinetic chain Kinetic chain –Each moving segment transmits forces to every other segment –Maintaining equilibrium involves the closed kinetic chain Foot = distal segment (fixed beneath base of support) Foot = distal segment (fixed beneath base of support)

(c) 2004 The McGraw-Hill Companies, Inc. All rights reserved Balance Disruption Body must be able to determine what strategy to utilize in order to control CoG Body must be able to determine what strategy to utilize in order to control CoG –Joint mechanoreceptors initiate automatic postural response Selection of Movement Strategy Selection of Movement Strategy –Joints involved allow for a wide variety of postures that can be assumed in order to maintain CoG Forces exerted by pairs of opposing muscles at a joint to resist rotation (joint stiffness) Forces exerted by pairs of opposing muscles at a joint to resist rotation (joint stiffness) Resting position and joint stiffness are altered independently due to changes in muscle activation Resting position and joint stiffness are altered independently due to changes in muscle activation

(c) 2004 The McGraw-Hill Companies, Inc. All rights reserved Ankle Strategy Ankle Strategy –Shifts CoG by maintaining feet and rotating body as a rigid mass about the ankle joints Gastrocnemius or tibialis anterior are responsible for torque production about ankle Gastrocnemius or tibialis anterior are responsible for torque production about ankle Anterior/posterior sway is counteracted by gastrocnemius and tibialis anterior, respectively Anterior/posterior sway is counteracted by gastrocnemius and tibialis anterior, respectively –Effective for slow CoG movements when base of support is firm and within LOS –Also effective when CoG is offset from center

(c) 2004 The McGraw-Hill Companies, Inc. All rights reserved Hip Strategy Hip Strategy –Relied upon more heavily when somatosensory loss occurs and forward/backward perturbations are imposed –Aids in control of motion through initiation of large and rapid motions at the hip –Effective when CoG is near LOS perimeter and when LOS boundaries are contracted by narrower base of support Stepping Strategy Stepping Strategy –Utilized when CoG is displaced beyond LOS –Step or stumble is utilized to prevent a fall

(c) 2004 The McGraw-Hill Companies, Inc. All rights reserved Damaged tissue results in reduced joint ROM causing a decrease in the LOS Damaged tissue results in reduced joint ROM causing a decrease in the LOS –Greater risk for fall Research indicates that sensory proprioceptive function is affected when athletes are injured Research indicates that sensory proprioceptive function is affected when athletes are injured Balance and Injury

(c) 2004 The McGraw-Hill Companies, Inc. All rights reserved Assessment of Balance Subjective Assessment Subjective Assessment –Traditionally assessed via the Romberg Test Feet together, arms at side, eyes closed Feet together, arms at side, eyes closed Loss of proprioception is indicated by a fall to one side Loss of proprioception is indicated by a fall to one side Balance Error Scoring System (BESS) Balance Error Scoring System (BESS) –Utilizes three stances Double, single, tandem on both firm and foam surfaces Double, single, tandem on both firm and foam surfaces –Athletes are instructed to remain motionless with hands on hips for 20 seconds –Unnecessary movements and correction of body position are counted as ‘errors’ (max score = 10) –Results are best utilized if compared to baseline data

(c) 2004 The McGraw-Hill Companies, Inc. All rights reserved

Semi-dynamic and Dynamic Balance tests Semi-dynamic and Dynamic Balance tests –Functional reach tests –Timed agility tests –Carioca –Hop test –Timed T-band kicks –Timed balance beam walks (eyes open and closed) Assessment of Balance

(c) 2004 The McGraw-Hill Companies, Inc. All rights reserved Injury and Balance Stretched/damaged ligaments fail to provide adequate neural feedback, contributing to decreased proprioception and balance Stretched/damaged ligaments fail to provide adequate neural feedback, contributing to decreased proprioception and balance –May result in excessive joint loading –Could interfere with transmission of afferent impulses –Alters afferent neural code conveyed to CNS –Decreased reflex excitation Caused via a decrease in proprioceptive CNS input Caused via a decrease in proprioceptive CNS input

(c) 2004 The McGraw-Hill Companies, Inc. All rights reserved –Joint receptors damaged during injury to lateral ligaments Results in Articular Deafferentation Results in Articular Deafferentation –Diminished signaling via afferent pathways –Reason behind balance training in rehabilitation –Orthotic and bracing intervention Enhance joint mechanoreceptors to detect perturbations and provide structural support for detecting and controlling sway Enhance joint mechanoreceptors to detect perturbations and provide structural support for detecting and controlling sway –Chronic ankle instability –Recovery of proprioceptive capabilities Instability vs. Deafferentation Instability vs. Deafferentation Ankle Injuries

(c) 2004 The McGraw-Hill Companies, Inc. All rights reserved –Ligamentous injury alters joint position detection ACL deficient subjects with functional instability exhibit this deficit (persist to some degree after reconstruction) ACL deficient subjects with functional instability exhibit this deficit (persist to some degree after reconstruction) May also impact ability to balance on ACL deficient leg May also impact ability to balance on ACL deficient leg –Mixed results have been presented with static testing Isometric strength could compensate for somatosensory deficits Isometric strength could compensate for somatosensory deficits Definition of functionally unstable may vary Definition of functionally unstable may vary –Role of joint mechanoreceptors with respect to end range and the far reaches of the LOS –More dynamic testing may incorporate additional mechanoreceptor input Results may be more definitive Results may be more definitive Knee Injuries

(c) 2004 The McGraw-Hill Companies, Inc. All rights reserved –Balance has been utilized at a criterion variable –Additional testing is necessary in addition to balance and sensory modalities –Postural stability deficits Deficits may last up to three days post-injury Deficits may last up to three days post-injury Result of sensory interaction problem - visual system not used effectively Result of sensory interaction problem - visual system not used effectively –Objective balance scores can be utilized to determine recovery curves for making return to play decisions Head Injuries

(c) 2004 The McGraw-Hill Companies, Inc. All rights reserved Balance Training Vital for successful return to competition from lower leg injury Vital for successful return to competition from lower leg injury –Possibility of compensatory weight shifts and gait changes result in balance deficits Functional rehabilitation should occur in the closed kinetic chain – nature of sport Functional rehabilitation should occur in the closed kinetic chain – nature of sport Adequate and safe function in the open chain is critical = first step in rehabilitation Adequate and safe function in the open chain is critical = first step in rehabilitation

(c) 2004 The McGraw-Hill Companies, Inc. All rights reserved Rules of Balance Training Rules of Balance Training –Exercise must be safe and challenging –Stress multiple planes of motion –Incorporate a multisensory approach –Begin with static, bilateral, and stable surfaces and progress to dynamic, unilateral, and unstable surfaces –Progress towards sports specific exercises Utilize open areas Utilize open areas Assistive devices should be within arms reach Assistive devices should be within arms reach Sets and repetitions Sets and repetitions –2-3 sets, 15 sec.  30 sec. repetitions –10 sets, 15 sec.  30 sec. repitions

(c) 2004 The McGraw-Hill Companies, Inc. All rights reserved Classification of Balance Exercises Static Static –CoG maintained over fixed base of support on stable surface Semi-dynamic Semi-dynamic –CoG maintained over fixed base of support while on a moving surface –CoG transferred over fixed base of support in selected ranges and/or directions within the LOS while on a stable surface Dynamic Dynamic –CoG maintained within LOS over a moving base of support while on a stable surface (involve stepping strategy) Functional Functional –Same as dynamic with inclusion of sports specific task

(c) 2004 The McGraw-Hill Companies, Inc. All rights reserved Phase I Phase I –Non-ballistic types of drills –Static balance training –Bilateral to unilateral –Utilize multiple surfaces to safely challenge athlete –With and without arms/counterbalance –Eyes open and closed –Alterations in various sensory information –ATC can add perturbations –Incorporation of multiaxial devices

(c) 2004 The McGraw-Hill Companies, Inc. All rights reserved Bilateral Stance Exercises

(c) 2004 The McGraw-Hill Companies, Inc. All rights reserved Phase II Phase II –Transition from static to dynamic –Running, jumping, and cutting Activities that require the athlete to repetitively lose and gain balance in order to perform activity Activities that require the athlete to repetitively lose and gain balance in order to perform activity Incorporate only when sufficient healing has occurred Incorporate only when sufficient healing has occurred –Semi-dynamic exercises should be introduced in the transition Involve displacement or perturbation of CoG Involve displacement or perturbation of CoG Bilateral, unilateral stances or weight transfers Bilateral, unilateral stances or weight transfers Sit-stand exercises, focus on posture Sit-stand exercises, focus on posture

(c) 2004 The McGraw-Hill Companies, Inc. All rights reserved –Unilateral Semi- dynamic exercises Emphasize controlled hip flexion, smooth controlled motion Emphasize controlled hip flexion, smooth controlled motion Single leg squats, step ups (sagittal or transverse plane) Single leg squats, step ups (sagittal or transverse plane) Step-Up-And-Over activities Step-Up-And-Over activities Introduction to Theraband kicks Introduction to Theraband kicks Balance Beam Balance Beam

(c) 2004 The McGraw-Hill Companies, Inc. All rights reserved Phase III Phase III –Dynamic and functional types of exercise –Start with bilateral jumping drills (straight plane) Advance to diagonal jumping patterns Advance to diagonal jumping patterns Increase length and sequences of patterns Increase length and sequences of patterns –Progress to Unilateral drills, vertical drills Unilateral drills, vertical drills Addition of implements Addition of implements –Tubing, foam roll, etc… –Final step = functional activity Subconscious dynamic control/balance Subconscious dynamic control/balance

(c) 2004 The McGraw-Hill Companies, Inc. All rights reserved Phase III Exercises