biomechanics of human movement biomechanics of balance

Download Biomechanics of Human Movement Biomechanics of Balance

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  • Slide 1
  • Biomechanics of Human Movement Biomechanics of Balance
  • Slide 2
  • Biomechanics of Balance Topics Applications Relating to Biomechanics of Balance Applications Relating to Biomechanics of Balance Determinants of Stability Determinants of Stability Factors Influencing Stability Factors Influencing Stability Role of Sensory Input in Balance Role of Sensory Input in Balance CNS Strategies for the Maintenance of Balance CNS Strategies for the Maintenance of Balance Enhancing Balance Enhancing Balance Assessment of Balance Assessment of Balance
  • Slide 3
  • Biomechanics of Balance Applications Incidence of Falls Incidence of Falls
  • Slide 4
  • Biomechanics of Balance Incidence of Falls 1.8 million falls among elderly result in medical treatment 1/3 of all Community-dwelling adults experience at least one fall yearly Sixth leading cause of death in over 65 age group
  • Slide 5
  • Biomechanics of Balance Applications Incidence of Falls Incidence of Falls Economic Impact of Falls Economic Impact of Falls
  • Slide 6
  • Falls..Economic Impact 16.4 Billion Dollars annually Average cost per fall - $9400 48% of cost paid by Medicare
  • Slide 7
  • Biomechanics of Balance Applications Incidence of Falls Incidence of Falls Economic Impact of Falls Economic Impact of Falls Influence of Pathology and Injury on Balance Influence of Pathology and Injury on Balance
  • Slide 8
  • Falls..Influence of Pathology on Balance Stroke Alzheimers Disease Head Injury Parkinsons Disease Vestibular Dysfunction Degenerative Joint Disease Orthopaedic Joint Injury Muscle Atrophy Diminished Balance
  • Slide 9
  • Biomechanics of Balance Applications Incidence of Falls Incidence of Falls Economic Impact of Falls Economic Impact of Falls Influence of Pathology and Injury on Balance Influence of Pathology and Injury on Balance Relationship between balance and posture implications Relationship between balance and posture implications
  • Slide 10
  • Balance Influence on Posture
  • Slide 11
  • Biomechanics of Balance Applications Incidence of Falls Incidence of Falls Economic Impact of Falls Economic Impact of Falls Influence of Pathology and Injury on Balance Influence of Pathology and Injury on Balance Relationship between balance and posture implications Relationship between balance and posture implications Sport Considerations Sport Considerations Performance Injury Prevention
  • Slide 12
  • Biomechanics of Balance Sport Considerations Performance Injury Prevention
  • Slide 13
  • Biomechanics of Balance What Causes Instability? Destabilizing External Torques Act on Segments Destabilizing External Torques Act on Segments GravityGravity Distribution and Position of MassDistribution and Position of Mass InertiaInertia External ForcesExternal Forces
  • Slide 14
  • Biomechanics of Balance What Produces Stability? Stabilizing Internal Torques Act on Segments Muscle Forces Muscle Forces Ligament forces Ligament forces Distribution and Position of Mass Distribution and Position of Mass External Forces External Forces
  • Slide 15
  • Biomechanics of Balance Stability Internal (Stabilizing) Torques = External (Destabilizing) Torques Stability is Maintained as long as the:
  • Slide 16
  • Biomechanics of Balance Factors Influencing Stability In Practical Terms: Sensory Factors Motor Factors Biomechanical Factors Size of the base of support Height of the COG above the base of support Mass
  • Slide 17
  • Biomechanics Center of Gravity Definition The point around which the mass of the body is equally distributed
  • Slide 18
  • Biomechanics Center of Gravity Factors Influencing Mass Mass Location of Mass position of the body segments Location of Mass position of the body segments Added (external) mass Added (external) mass
  • Slide 19
  • Biomechanics of Balance Control of Balance Sensory CNS Motor
  • Slide 20
  • Biomechanics of Balance Sensory Input Purpose: To provide the CNS with information about the direction and magnitude of De-Stabilizing Torques To monitor the effects of Internal Stabilizing Torques Components: Vision Somatosensory Vestibular
  • Slide 21
  • Biomechanics of Balance Somatosensory Muscle Spindles Muscle Spindles Joint Receptors Joint Receptors Tendon Organs Tendon Organs Mechanoreceptors Mechanoreceptors
  • Slide 22
  • Biomechanics of Balance Biomechanics of Balance Vestibular System - The Inner Ear Head Linear Acceleration Head Linear Acceleration Head Rotation (angular accelerations) Head Rotation (angular accelerations) Head Position Head Position The Vestibular System provides information about:
  • Slide 23
  • Biomechanics of Balance Sensory Input and Control 1)Activates Supporting Musculature 2)Activates Muscle synergies to produce correction Sensory Input activates reflexes that (in order):
  • Slide 24
  • Biomechanics of Balance CNS and Control The CNS Implements Strategies that are intended to be selectively applied to various levels of instability Quiet Stance maintained by postural alignment, associated joint stiffness and muscle tone
  • Slide 25
  • Biomechanics of Balance The Ankle Strategy Minimal Instability the Ankle Strategy Simple Response Rotation at the ankle Inverted Pendulum
  • Slide 26
  • Biomechanics of Balance The Hip Strategy Greater Instability the Hip Strategy More complex Increased translation of mass Adjustment at Hip
  • Slide 27
  • Biomechanics of Balance The Stepping Strategy Maximum Instability the Stepping Strategy Most complex Multiple segments involved Slowest
  • Slide 28
  • Biomechanics of Balance Muscle Response to Instability Muscle Response to Instability Results in a Distal to Proximal Activation Pattern Gastroc/Soleus 90 100 msec Hamstrings 120- 130 msec Psoas 130 140 msec
  • Slide 29
  • Biomechanics of Balance Can Balance Be Improved???? YES !! Sensory Input CNS Processing Muscle Output Cognitive Factors All capable of DegradationorImprovement (sometimes)
  • Slide 30
  • Biomechanics of Balance Can Balance Be Improved???? Assistive Devices
  • Slide 31
  • Evaluating Balance Force Plate

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