BIOL1630 SSP Falls Prevention

Main ideas and lessons conveyed

• The video explains how biomechanics principles from the course can be applied to a clinical population, using older adults’ fall prevention as the scenario.
• Fall risk is influenced by multiple interacting factors, including:
  • History of a previous fall
  • Muscle strength and ability to control sway, especially lower-limb control in both:
    • Static conditions (standing)
    • Dynamic conditions (moving)
  • Sensory impairments, such as:
    • Vision/depth perception
    • Cutaneous/foot sensation
  • Gait and posture variables, including:
    • Step length
    • Stride length
    • Step width
    • Base of support
  • Environmental factors, such as:
    • Uneven surfaces
    • Friction
    • Typical home/community walking environments
  • Other health factors, including:
    • Incontinence
    • Cognitive impairment
    • Delirium

Key risk factors and assessment concepts (as described)

• Falls history

  • A prior fall is emphasized as a major predictor of future falls.

• Strength & sway control

  • Focus is placed on controlling postural sway while standing and while moving.

• Sensory information

  • Vision and depth perception (e.g., judging steps/edges such as a coffee table corner)
  • Proprioceptive/cutaneous input from the bottom of the feet
  • Gaze and awareness related to walking/foot placement

• Gait mechanics and base of support

  • Step length: shuffling/small steps may indicate instability.
  • Stride length and step width:
    • Wider step width / feet farther apart = greater base of support
    • Encourages avoiding “catwalk” walking (feet crossing / narrow stance) when appropriate.
  • Overall sway and movement quality can help infer current body control over the feet.

• Mobility environment

  • Frictional forces, uneven ground, and variable home/community surfaces matter.
  • The video highlights that older adults regularly navigate conditions that challenge stability.

Methodology / practical training approach

1) Strength training to counter sarcopenia (age-related muscle loss)

• Core concept

  • Aging involves sarcopenia (loss of muscle mass), which reduces muscle cross-sectional area and affects force production.

• Intervention strategy

  • Use strength training/exercise programs to improve strength and torque output.

• Training components mentioned

  • Rate of force development (RFD)
    • As people age, contraction velocity decreases
    • Incorporate training that targets faster force production
  • Neurological changes
    • Loss of motor units and changes in their number/size contribute to weakness

• Exercise progression examples

  • Start with isolation (if highly deconditioned / high fall risk)
    • Example: leg extension to isolate quadriceps
    • Goal: improve safer transitions (e.g., getting out of a chair or off the toilet)
  • Progress to dynamic, weight-bearing functional strength
    • Include:
      • Sit-to-stand stepping
      • Stepping tasks
      • Turning while on their feet
    • Rationale: simulate tasks encountered outside (more functional, less isolated)
  • Progress to power-based/reactive training
    • Convert strengthening into power training:
      • Standing quickly
      • Taking fast steps
      • Reaction stepping and moving
    • Goal: improve control across different movement rates during ambulation

2) Use regressions/progressions via moment arms and task difficulty (chair height, stair height)

• Sit-to-stand regression/progression

  • Regression
    • Start from a higher chair/plinth to reduce difficulty
    • Reason: lowering the chair increases required force due to changing hip/knee moment arms against gravity/body weight
  • Progression
    • Lower seat height over time toward more challenging heights (e.g., toilet height, standard dining chair height)

• Step-up/step-down regression/progression

  • Regression
    • Start with small step height
    • Short range/smaller loads help build capacity safely
  • Progression
    • Increase step height to increase hip contribution and overall force demands
    • Add load when appropriate (example: holding dumbbells or a medicine ball)
  • Eccentric control emphasis
    • For step-downs, starting with short-range eccentric control is suggested

3) Balance training: manipulate base of support + sensory/attention challenges

• Base of support manipulation

  • Prescription principle: challenge base of support to affect sway control and perturbation response.
  • Examples of harder conditions:
    • Reduce stance width (e.g., standing on one leg)
    • Use a movable surface
    • Change surface heights

• Add distracting elements / sensory changes

  • Incorporate upper limb movements and head turns
  • Purpose: alter visual input and sensory integration so the person develops strategies when the center of gravity moves toward/outside the base of support

4) Dynamic balance progression: from controlled stepping to complex real-world tasks

• Step and directional movement progression

  • Walking forward in a straight line
  • Walking forward/backward
  • Directional stepping at angles (example: “clock face” stepping: diagonals, forward/back, crossing steps)

• Increasing instability

  • One-leg standing reaching (example: star excursion-type activity)
  • Reaching toward a cone while maintaining controlled sway on one leg

• Obstacle and turning progression

  • Obstacles: cones/markers requiring turning around objects
  • Narrow/tightrope-like turning:
    • Bring feet together or perform tight turns with reduced stability

• Teaching component

  • Teach/explain techniques and train awareness for using strategies outside the lab/clinic (e.g., shopping or meeting friends)

5) Gait retraining: improve clearance and step characteristics

• Foot clearance and swing-phase control

  • Emphasize exaggerated stepping and adequate clearance
  • Use cues for knee drive/marching to encourage lift
  • Keep toes up to activate tibialis anterior for clearance

• Practice variations

  • On-the-spot marching
  • Forward walking
  • Different speeds

• Step length & width

  • Slow down movement while aiming for a longer step
  • Monitor step width and ensure it supports stability

6) Safe use of walking aids during training (and ensuring they don’t mask instability)

• Single point stick

  • Holding a stick can increase base of support
  • Strategy use:
    • Evaluate that the aid is appropriate
    • Check it doesn’t change posture in a way that worsens instability
  • Mentioned goal: support independent activities (e.g., shopping)

• Four-wheel walker

  • Use during gait retraining to:
    • Build confidence
    • Practice harder maneuvers safely
    • Provide supervision while learning stepping around obstacles in a controlled environment

7) Footwear and environment management

• Footwear fit

  • Recommend properly fitted shoes (not too large)
  • Excess length can reduce toe clearance and limit ankle ROM effectiveness

• Practical implication

  • Ensure well-fitted footwear both outside and indoors:
    • Different home surfaces exist (carpeted areas vs tiles in bathroom; slippery spots in kitchen)

8) Course-to-clinic connection (biomechanics as a decision tool)

• The video connects training decisions to biomechanics concepts such as:
  • torque
  • moment arms
  • levers
• Key purpose
  • Determine whether a change is a progression (harder) or regression (easier)
• Main takeaway
  • Biomechanics applies beyond performance enhancement; it can support real clinical prevention and training.

Speakers / sources featured

• Speaker 1 (unidentified; introduces the scenario and key lessons)
• Shari O’Brien (guest/expert clinician explaining fall risk factors and training content)
• UQ Healthy Living Clinic (site visited; referenced as a source of information)