Balance Its Functional Role in Rehabilitation Gait

1. Balance & Its Functional Role in Rehabilitation & Gait Sally Paulson Ph.D., ATC, CSCS Shippensburg University

3. What is balance? Balance is the means in which individuals maintain their body position while stationary or mobile in relationship to the environment Balance requires input from Visual system Vestibular system Proprioception Muscular strength, endurance & flexibility CNS control balance through motor commands The vestibular system is located within the inner ear. It sends information about horizontal or vertical spatial orientation, direction and locomotion to the cerebellum and brain stem to maintain upright posture or movements. The visual or oculomotor system aids in providing afferent information concerning kinesthetic awareness in relation to the environment. It works in conjunction with the vestibular system when the body and/or environment are in motion (Anderson & Behm, 2004; Arnheim & Sinclair, 1985; Auxter et al., 2005; Blackburn et al., 2000; Carter, Kannus, & Khan, 2001; Charles et al., 2002/2003; Dieterich, 2004; Houglum, 2005) Proprioception, also known as somatosensory, is the ability of the body to receive, respond, and interpret sensory information consciously and unconsciously to correct and maintain movement and/or posture The vestibular system is located within the inner ear. It sends information about horizontal or vertical spatial orientation, direction and locomotion to the cerebellum and brain stem to maintain upright posture or movements. The visual or oculomotor system aids in providing afferent information concerning kinesthetic awareness in relation to the environment. It works in conjunction with the vestibular system when the body and/or environment are in motion (Anderson & Behm, 2004; Arnheim & Sinclair, 1985; Auxter et al., 2005; Blackburn et al., 2000; Carter, Kannus, & Khan, 2001; Charles et al., 2002/2003; Dieterich, 2004; Houglum, 2005) Proprioception, also known as somatosensory, is the ability of the body to receive, respond, and interpret sensory information consciously and unconsciously to correct and maintain movement and/or posture

4. Balance is affected by� Muscular strength Fatigue of the LE muscles occurs earlier due to inadequate strength This can result in diminished coordination With age strength decreases, which results in a decline in balance (Martin & Morgan, 1992; Syed & Davis, 2000) CNS Injury to the brain or spinal cord might interrupt communication between the body part/system & the CNS Medications Blackburn et al., 2000; Carter et al., 2001; Clark, 2004; Hamilton & Luttgens, 2002; Houglum, 2005; Nitz et al., 2003

5. Balance is affected by� Pathological &/or age-related changes to vestibular & visual systems Tai Chi was found to balance improvement via the vestibular component of the sensory organization test in healthy, elderly subjects (Tsang & Hui-Chan, 2004) Someone with vestibular defect/injury might present with Gait alterations & decreased static balance Limited control of the COG within the base of support (Krebs et al., 2002) Age Nitz et al. 2003 concluded that medial-lateral balance declines with age in women, especially between the ages of 40 & 60 Size of the base of support (BOS) Smaller BOS requires finer body adjustments to maintain balance (Anderson & Behm, 2004)

6. Balance is affected by� Injuries to the LE Normal alignment & stability of the supporting LE decreases friction; which contributes to the smoothness of gait (Sailbene & Minetti, 2003) May result in inefficient energy expenditure during walking or running (Sailbene & Minetti, 2003) May lead to the COG to fall outside of the BOS � increase risk of falling (Blackburn et al., 2000; Clark, 2004) Balance impairments have been related to risk of injury &/or risk of re-injury May damage joint proprioceptors which contribute to maintaining balance Restoring proprioception following injury increases the body�s awareness of joint position � increase stability & orientation during static or dynamic movement (Laskowski, et al. 1997) Tropp et al. (1984) reported soccer players who presented with > 2 SD above normal on postural sway measures had a significantly higher risk of injury to the LE Hamilton & Luttgens, 2002; Hills et al., 2001, 2002; Houglum, 2005; Martin & Morgan, 1992; Spyropoulos et al., 1991 Proprioceptors can be injured directly (tearing of structures surrounding the joint) or indirect � effusion to the joint Proprioceptors can be injured directly (tearing of structures surrounding the joint) or indirect � effusion to the joint

7. Balance is affected by� Obesity McGraw et al. (2000) reported obese boys spent significantly greater time in the double support phase & may have less dynamic & static balance Thigh mass of obese individuals may be disproportional to the rest of the body Results in an increase in leg mass & affects the internal work of the muscles (Martin & Morgan, 1992; Sailbene & Minetti, 2003) Increase in step width (Hills et al., 2001, 2002) Additional mass can alter the position of the COG; which can lead to falls (Clark, 2004) Has been linked to gait changes, pathologies to the LE, loss of mobility & increases in energy expenditure Blackburn et al., 2000; Hamilton & Luttgens, 2002; Houglum, 2005; Spyropoulos et al., 1991

8. On the Contrary McHugh et al. (2006) examined risk factors for noncontact ankle sprains in high school athletes Measured balance via a tilt board & hip strength Found balance & hip strength were not risk factors for noncontact ankle sprains However, previous ankle injuries & being overweight (especially in males) were found to be significant risk factors

9. Balance & Rehabilitation Blackburn et al. (2000) found dynamic & semi-dynamic balance improved in all subjects that completed an ankle rehabilitation program vs. subjects that did not (control group) Rehab programs were: (a) strength training, (b) proprioception training, & (c) strength & proprioception training examined the contribution of muscular strength and proprioception in maintaining balance and joint stability through the use of four different ankle rehabilitation protocols 32 were randomly assigned to one of four groups (a) control, (b) strength training, (c) proprioception training, and (d)�strength and proprioception training. Three measurements of balance were completed before and after a six-week training program. These were dominant single-leg static balance for 10 s on a force plate with eyes closed, For the semidynamic balance test, the subjects stood on their dominant leg for 10 s on the Biodex Stability System with their eyes closed. Dynamic balance was measured using a modified Bass Test of Dynamic Balance, with a score of 100 being the maximum. The results suggested there was no improvement or differences between groups on any of the three measures of balance. However, all three training groups improved as compared to the control group on semidynamic balance and dynamic balance. The authors felt the use of any of the rehabilitation programs were equally effective in improving balance and joint stability (Blackburn et al., 2000). examined the contribution of muscular strength and proprioception in maintaining balance and joint stability through the use of four different ankle rehabilitation protocols 32 were randomly assigned to one of four groups (a) control, (b) strength training, (c) proprioception training, and (d)�strength and proprioception training. Three measurements of balance were completed before and after a six-week training program. These were dominant single-leg static balance for 10 s on a force plate with eyes closed, For the semidynamic balance test, the subjects stood on their dominant leg for 10 s on the Biodex Stability System with their eyes closed. Dynamic balance was measured using a modified Bass Test of Dynamic Balance, with a score of 100 being the maximum. The results suggested there was no improvement or differences between groups on any of the three measures of balance. However, all three training groups improved as compared to the control group on semidynamic balance and dynamic balance. The authors felt the use of any of the rehabilitation programs were equally effective in improving balance and joint stability (Blackburn et al., 2000).

10. Balance & Prevention Myer et al. (2006) compared plyometric training to balance training on LE biomechanics Plyometric group Exercises included jumps, hops, box drops & cutting Maximal effort Balance group Addressed dynamic stabilization & core strengthening Focus was on challenging the COG through single-leg movements or adding external weight Pre/posttest 3D & force plate measurements were taken while performing (2) tests Drop vertical jump (31 cm in height) Single-legged medial drop landing task Results suggested the both groups demonstrated improvements in LE valgus motion Drop vertical jump � Significant decreases were noted in both groups at the hip & ankle Single-legged medial drop � Significant decreases at the knee for both groups Authors concluded both training programs can decrease LE valgus motion; however, the improvements found were training and task specific Myer et al (2006) 18 (age � 15.9+-0.8 plyo; 15.6+-1.2 bal) high school female volleyball athletes, completed 7-weeks of training for a total of 18 training sessions Randomly assigned to Plyo group or balance group 2 ACL neuromuscular protocols were modified for the training programs PLYO � all jumps, squat jumps, barrier jumps, line jump, lunge jumps, box drops, tuck jumps w/ crunch or butt kicks, corssover hops, froward/backward hop feedback was provided to all subjects during the training program to ensure correct tech. & minimizing valgus motion at the knee � both groups were completing the same resistance training protocols BAL � line jumps, BOSU training, swiss ball training, box drops, sinlge-leg squats & line hops, crunches, hyperextensions, lateral crunches DVJ � drop of box onto two force plate (one for each foot) and do a vertical jump Single-leg jump � balanced on 1-leg on a 13.5 cm box adjacent to force plate � dropped off box medially, land on same leg & hold three trials were recorded under each testing condition first contact on the force plate was used to analyze stance phase Results � DVJ: hip adduction max angle decreased and ankle eversion decreased at initial contact PLYO � sign. increased knee flexion at contact & max angle SLMD � knee abduction angle decreased at initial contact BAL � sign. Increased max. knee flexion at initial contact Myer et al (2006) 18 (age � 15.9+-0.8 plyo; 15.6+-1.2 bal) high school female volleyball athletes, completed 7-weeks of training for a total of 18 training sessions Randomly assigned to Plyo group or balance group 2 ACL neuromuscular protocols were modified for the training programs PLYO � all jumps, squat jumps, barrier jumps, line jump, lunge jumps, box drops, tuck jumps w/ crunch or butt kicks, corssover hops, froward/backward hop feedback was provided to all subjects during the training program to ensure correct tech. & minimizing valgus motion at the knee � both groups were completing the same resistance training protocols BAL � line jumps, BOSU training, swiss ball training, box drops, sinlge-leg squats & line hops, crunches, hyperextensions, lateral crunches DVJ � drop of box onto two force plate (one for each foot) and do a vertical jump Single-leg jump � balanced on 1-leg on a 13.5 cm box adjacent to force plate � dropped off box medially, land on same leg & hold three trials were recorded under each testing condition first contact on the force plate was used to analyze stance phase Results � DVJ: hip adduction max angle decreased and ankle eversion decreased at initial contact PLYO � sign. increased knee flexion at contact & max angle SLMD � knee abduction angle decreased at initial contact BAL � sign. Increased max. knee flexion at initial contact

11. Balance & Gait Maintaining balance while walking is a challenge for the CNS Internal & external forces acting on the body which the CNS must process (Harris & Wertsch, 1994) The body continually moves from a stable body position (double support) to an unstable position (single support) Placement of the swing limb during double support is crucial for the CNS to make adjustments to maintain balance Winter (1991) reported three measures related to balance when walking (a) toe clearance, (b) the velocity of the heel at contact, & (c) hip & knee moment force Gait analysis has been used a tool to measure balance (Lee & Pollo, 2001) individual characteristics of walking are influenced by (a) personality, (b)�shoes, (c) height, and (d) body weight If something happens to one of these at any point while moving then a fall is likely to occur. For example, when the stance leg is leaving the ground and the toe catches on the ground, then the person may fall. This fall can be prevented if the stance leg is stable and the CNS is able to recover balance quickly (Winter, 1991). Joint moment forces are the net result from muscle contractions, lower extremity segment interactions, friction, and the external forces acting on the body (Dufek, Schot, & Bates, 1990) individual characteristics of walking are influenced by (a) personality, (b)�shoes, (c) height, and (d) body weight If something happens to one of these at any point while moving then a fall is likely to occur. For example, when the stance leg is leaving the ground and the toe catches on the ground, then the person may fall. This fall can be prevented if the stance leg is stable and the CNS is able to recover balance quickly (Winter, 1991). Joint moment forces are the net result from muscle contractions, lower extremity segment interactions, friction, and the external forces acting on the body (Dufek, Schot, & Bates, 1990)

12. Balance & Gait Effects of Balance Exercises on the Analysis of Selected Kinetic and Kinematic Variables of Gait in Developmentally Disabled (DD) Obese Adults Additional body mass, & decreases in strength place obese adults at risk for falls especially during unstable period during gait 10-week balance program did not yield significant changes in the selected gait variables However, interesting changes within the TX group were noted TX group decreased knee angle at heelstrike by 7.57� (medium effect size) Cadence of the TX group increased by 7.22 steps per minute Six out of the nine subjects in the TX group increased cadence Variables examined: Kinematic variables of gait Stride length Cadence Joint angles Joint velocities Percentage of stance and swing time Joints analyzed were the ankle, knee, and hip Kinetic variables of gait COG during the swing phase Ground Reaction Force (GRF) during the stance phase Balance program was offered through the College for Living Program at Life Styles, Inc. three days a week for 10 weeks Class consisted of a warm-up, balance exercises, & a cool-down The balance exercises were simple and progressively became more challenging The exercises mainly addressed the visual and proprioceptive systems Vestibular balance was addressed toward the end of the 10 weeks Variables examined: Kinematic variables of gait Stride length Cadence Joint angles Joint velocities Percentage of stance and swing time Joints analyzed were the ankle, knee, and hip Kinetic variables of gait COG during the swing phase Ground Reaction Force (GRF) during the stance phase Balance program was offered through the College for Living Program at Life Styles, Inc. three days a week for 10 weeks Class consisted of a warm-up, balance exercises, & a cool-down The balance exercises were simple and progressively became more challenging The exercises mainly addressed the visual and proprioceptive systems Vestibular balance was addressed toward the end of the 10 weeks

13. Subject Two � Treatment Group Pre Gait Video PRE Gait.avi

14. Subject Two � Treatment Group Post Gait Video Post Gait.avi

15. Individual Changes in Gait Left � Subject one � posttest vertical GRF occurred earlier in the gait cycle � indicating the increase in acceleration of the body and posttest had two distinct peaks Right � subject two again the posttest vertical GRF occurred earlier in the gait cycle indicating an increase in acceleration and there were two distinct peaks Left � Subject one � posttest vertical GRF occurred earlier in the gait cycle � indicating the increase in acceleration of the body and posttest had two distinct peaks Right � subject two again the posttest vertical GRF occurred earlier in the gait cycle indicating an increase in acceleration and there were two distinct peaks

16. Balance Exercises Should be simple & progressively become more challenging They can be designed to address any of the systems that affect balance

17. Static Balance Exercises Double to single leg standing Alter the width of BOS Semi-tandem to tandem Add external equipment to stress the visual or vestibular systems Playing catch Unstable surface Foam BOSU Eyes open to eyes closed Table position alternate hands & knees while in table position Swiss balls Alternate arm/leg Marching UE or LE exercises Vestibular exercises added later � hokey pokey, walking around large circle & small circle, turning around in circles and changing directionVestibular exercises added later � hokey pokey, walking around large circle & small circle, turning around in circles and changing direction

18. Dynamic Balance Exercises Trampoline Closed-chain kinetic exercises Walking Forward heel-to-toe Sideways, on toes, on heels or backward between double lines that progressively get narrower Squats Step-ups Mini hops Jumping rope Swiss balls BOSU Circle activities � vestibular exercises Sport-specific activities Obstacle course Games Freeze tag Statues Hopscotch Twister Follow the leader Scooter boards Pull/push self with hands or feet � sitting or lying prone Sitting or lying prone spin self in one direction, stop & change directions (vestibular) Push/pull self through obstacle course or rope Relay races

19. Assessing balance Static balance tests include (a) parallel stance with feet together or shoulder width apart (b) semi-tandem stance (c) tandem stance (d) Romberg Test (e)�one legged stance Measure postural sway via a force plate under any of these conditions to detect the oscillations of the center of pressure These are timed & a score of 30 s without using hand support is generally considered good The visual & vestibular systems can be tested in these positions with eyes open & closed (Dieterich, 2004) Sensory Organization Test This test provides an outcome variable called an equilibrium score, which is based on the visual, proprioceptive, & vestibular systems to maintain standing balance (Chaudhry et al., 2004) Anemaet & Moffa-Trotter, 1999; Clark, 2004; Houglum, 2005

20. Assessing balance Dynamical balance measurements include: Walking heel-to-toe for 10 feet (Clark, 2004) Performing this task without looking at one�s feet is a method to assess vestibular & visual balance (Auxter et al., 2005) Timed get-up-and-go test (Carmeli et al., 2002) Berg Functional Balance Scale � includes static & dynamic assessment (designed for elderly) Tinetti Balance Test � shorter than Berg, addresses static & dynamic

21. Assessing Functional Strength & Proprioception in LE Line jumping Forward & backward Side-to-side Single leg Score of > 20 s is �good� Four squares Make a square Person jumps clockwise around the square single legged Repeated on opposite leg & counterclockwise Count the number of foot contacts in 20 s Vertical jumping Single leg jumping Count the number of jumps completed in 20 s Bounding Single leg long jump Bound forward � land � bound forward again Take the average length of (2) jumps With these tests one can compare bilaterally both in time & number of jumps

22. Conclusion The inclusion of balance exercises May decrease the risk of injury or reinjury Can be incorporated as a preventative measure Should be included in exercise programs for Obese individuals, elderly, people with a DD, LE injury rehab, or for someone with a balance deficiency

23. References If you would like a complete list of references please contact me via email & I will send you an electronic copy Sally Paulson Ph.D., ATC, CSCS Shippensburg University Dept. of Exercise Science sapaul@ship.edu 717 477 1274

24. Questions