Effects of Task-Specific Step Training on Reactive Balance

Not Applicable

Completed

Brief Summary: The goal of this clinical trial is to evaluate a novel and pragmatic (i.e., not requiring specialized equipment) task-specific step training regimen that aims to improve reactive balance after tripping. The main questions it aims to answer are:

* Does this step training regimen improve reactive balance after tripping compared to no training?

* How well does this step training regimen improve reactive balance compared to treadmill training, which is a more commonly studied reactive balance training regimen that uses a specialized treadmill.

Participants will:

* complete step training or treadmill training (or no training if assigned to the control group) twice a week for three weeks

* experience a laboratory-induced trip three weeks later to evaluate their reactive balance

Recruitment & Eligibility

Inclusion Criteria

Exclusion Criteria

participants must pass a health screening involving a questionnaire that will be reviewed by a health care specialist.
participants must not have clinical osteoporosis as indicated by a bone mineral density of the lumbar vertebra and proximal femur of t<-2.0 as obtained from dual energy x-ray absorptiometry (DEXA), or a DEXA scan completed within the last year.

Primary Outcome Measures

Name	Time	Method
Trunk Angle at Touchdown of the First Recovery Step	1 week after the 3-week intervention	After a laboratory-induced trip: Angle from vertical of a line connecting midpoint of greater trochanter markers and midpoint of the acromion markers
Trip Outcome	1 week after the 3-week intervention	This is a binary variable that has a value of either "fall" or "recovery." After a laboratory-induced trip, trip outcome will be assign to one of the following two values: "fall" if a participant is fully and continuously supported by the harness as observed from video, or if the harness force applied to the participant, integrated over time from trip onset until 1 second after touchdown of the first recovery step, is greater than 40% of body weight \* seconds. The harness force will be measured by a uniaxial load cell. "recovery" if the harness force applied to the participant, integrated over time from trip onset until 1 second after touchdown of the first recovery step, is less than 40% of body weight \* seconds. The harness force will be measured by a uniaxial load cell.

Secondary Outcome Measures

Name	Time	Method
Recovery Step Length	1 week after the 3-week intervention	After a laboratory-induced trip, the distance between a lateral malleolus marker of the stance limb and a lateral malleolus marker of the stepping foot at touchdown
Sacrum Height at Touchdown of the First Recovery Step	1 week after the 3-week intervention	After a laboratory-induced trip, the minimum distance between the walkway and the greater trochanter marker on the non-tripping limb during trip recovery.
Gait Speed	1 week after the 3-week intervention	The average forward speed of the participant prior to the laboratory-induced trip.
Average Step Speed	1 week after the 3-week intervention	After a laboratory-induced trip, the distance between a lateral malleolus marker of the stance limb and a lateral malleolus marker of the stepping foot at touchdown divided by the time from impact with the trip obstacle and touchdown of the initial recovery step.
Trip Recovery Strategy	1 week after the 3-week intervention	This is a binary variable that has a value of either "elevating" or "lowering." Elevating or lowering, depending upon how the participant uses the foot that trips on the obstacle after the laboratory-induced trip. If the foot is elevated over the obstacle, then this will be elevating. If the foot is lowered to the ground and the opposite foot first steps over the obstacle, then this will be lowering. The measurement tool to determine this outcome is a video recording of the trip, and this outcome has no units.