Mechanisms of Fall Resistance to Diverse Slipping Conditions
Condition: Slipping and Falls
Study type: Interventional

Summary: 
      Using movement analysis, the investigators will determine the relationships between diverse
      slip conditions, reactive responses to slips from those conditions, and slip vulnerability
      across the gait cycle to generate new data that may guide future interventions.
    

Detailed description: 
      Recent evidence suggests most slip-related falls in daily life happen in diverse slipping
      conditions where the ground is not level, or the person is turning or changing direction.
      While slips that occur during straight walking on level ground and the responses to those
      slips are relatively well understood, very little is known about slips that occur while
      walking on slopes or curved paths and which reactive responses are effective to prevent falls
      in such conditions. This limits the ability of clinicians to incorporate a diverse range of
      slipping experiences into fall prevention interventions. Understanding how reactive responses
      and slip vulnerability depend on diverse slip conditions may guide future interventions that
      promote a more general fall resistance to the broader range of slips we encounter in the real
      environment. Thus, the objective of this research project is to determine the impact of turns
      and slopes on reactive movements and fall vulnerability. The aims of this study are (1) to
      determine the effects of path curvature on reactive movements and slip vulnerability at
      different times in the gait cycle, and (2) to determine the effects of ground slope on
      reactive movements and slip vulnerability at difference times in the gait cycle. The
      investigators hypothesize that diverse slipping conditions will change the reactive responses
      involving protective stepping and arm swing. In addition, the investigators hypothesize that
      the distinct dynamics of turns and slopes produce maximum vulnerability to slips at different
      times in the gait cycle compared to slips during straight walking on level ground. To
      evaluate these aims, the investigators will administer slip perturbations on slopes that vary
      in both magnitude and direction, on curved paths that vary in curvature, and with slip onset
      that varies across early, middle, and late stance. Understanding the relationships between
      diverse slipping conditions, reactive responses, slip severity and fall vulnerability may
      guide future research and training interventions towards more comprehensive fall resistance
      ability.
    

Intervention name(s): Slips on Turns; Slips on Slopes
Intervention type(s): Other; Other
Intervention description(s): Subjects will be administered a slip at 3 different times in the gait cycle for each of 3 different patch curvatures and 2 different legs for a total of 18 slip episodes. Slips will be delivered while walking along a straight path (infinite radius), or curved paths with radii 2, or 1 meters.; Slips will be administered at 3 different times in the gait cycle over sloped ground surface of no slope, ±5.0 and ±10.0 degrees slopes in the direction of walking, and 5.0 and 10.0 degrees perpendicular to the direction of walking. On slopes perpendicular to the direction of walking, slips will be administered to the uphill or downhill foot. A total of 27 slip episodes will be administered. Sloped walking surfaces will be generated with the CAREN system treadmill.
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Basic Science