Does Fall Arrest Strategy Training Improve Capacity to Prevent Fall-Related Injury in Older Women?

Overview

Falls are the leading cause of injury hospitalization for seniors across Saskatchewan and addressing the underlying causes is a provincial health priority. Older women are more vulnerable to the most common fall-related injuries (upper body) during forward falling while walking. Exercise programs designed to improve balance and strength can reduce fall risk but it is not known if specific exercises targeted to upper body strength and agility can improve chances for safe landing when a fall is inevitable. The investigators have developed such a program, Fall Arrest Strategy Training (FAST) and successfully piloted the feasibility of the exercises to be included in a standard fall prevention program. FAST is meant to increase arm strength, reaction time, trunk control, and teach better landing techniques. The potential efficacy of such an intervention to improve landing capacity has not been studied in older women. Thirty-two women age 60 years or older will be randomly assigned to either FAST or a Standard Exercise group. Half will do standard exercises targeting balance, mobility and lower extremity strength; the other half will do the same exercises with the addition of FAST. Both groups will exercise twice per week for 12 weeks. Participants will be tested before and after for arm strength, reaction time, balance, mobility and the ability to control body descent (absorb energy) using a technique we developed in our lab. While in a safety harness, participants will simulate a forward fall onto a platform that measures energy during impact. While completely preventing falls is not possible, this study will help the investigators learn if simple exercises like FAST combined with balance training can decrease fall risk AND reduce the risk of serious injury when a fall is unavoidable. It will help address the growing personal and societal cost of fall-related injury. This study will also inform future research targeted to include a large-scale trial evaluating the impact and implementation of FAST training in older adults across the spectrum of care and development of a computer simulation model to determine which factors are most important for reducing the risk of fall-related injury.

Falls are the current leading cause of fracture and head injury in older adults in Saskatchewan and will continue to be a growing health concern given the aging population. Determining effective and feasible interventions to prevent the downward spiral of failing health, admission to long term care and even death following a serious fall-related injury is important to Saskatchewan seniors, the health care team, policy makers and the public at large. Exercise is known to decrease fall risk in community-dwelling older adults and should theoretically also reduce risk for injury during a fall; however, there are no clinical trials evaluating exercises designed specifically to enhance safe landing when a fall is imminent. Ideally, the health care team would like to support older adults in preventing all falls but in reality, this is not possible. Developing an intervention targeting both fall AND injury prevention (in the event a fall is inevitable) should enhance the effectiveness of exercise for reducing fall-related injury. This study will investigate the efficacy of novel Fall-Arrest Strategy Training (FAST) to improve the physical capacity to arrest a fall and reduce injury risk in older community-dwelling women. The risk of injury from falls depends on both the severity of impact and neuromuscular capacity such as bone and muscle strength of the affected body part. Sixty percent of all falls in older adults occur in a forward direction, more often in women than men. Forward falls are typically combined with hand contact as a protective response to prevent head, hip or torso injury. The effectiveness of these important protective strategies unfortunately decreases with aging. Evidence suggests forward fall arrest strategies can be modified to improve safe landing and reduce impact forces. The critically important question is whether older adults, in particular older women at high risk for fracture, can enhance their ability to efficiently utilize fall arrest strategies intended to diminish both the risk of head impact and the risk of wrist fracture. Fall Arrest Strategy Training (FAST) is a new, innovative exercise intervention the investigators have developed uniquely focusing on enhancing upper extremity (UE) strength, response time, trunk control and specific strategies to safely lower the body. The severity of impact with a forward fall is determined primarily by pre-impact neuromuscular factors - muscle strength, movement time, and kinematic placement of the upper extremity (UE) which may also depend on available joint range of motion (ROM). FAST uses functional exercises specifically targeted to address these factors and are easily incorporated into general fall prevention programs. Staying on Your Feet is an established and effective fall prevention program offered to community-dwelling older adults in the Saskatoon Health Region. The feasibility of implementing FAST into Staying on Your Feet was verified in a previous pilot study. The important extension of this work is to determine if functional improvements result in improved fall-specific neuromuscular capacity and ability to absorb energy. The focus of this project is to further advance our understanding of the effect of FAST on functional fall risk outcomes and fall-arrest capacity in older women. The goal of FAST is to increase fall-arrest capacity, defined as neuromuscular ability that could be utilized to prevent and minimize injury during a fall. While fall-related injury risk is difficult to measure directly, increases in fall-arrest capacity will likely lead to a reduction in that risk. Therefore, the effectiveness of injury risk reduction interventions such as FAST can be measured by their ability to increase fall-arrest capacity. One important factor recently emerging in the falls literature is energy absorption; older women absorb less energy in their UE during a controlled forward descent compared to younger women. The investigators have developed an experimental apparatus which can measure UE energy absorption in both controlled and unexpected forward body descents. Muscle strength, particularly surrounding the shoulder girdle and elbow, is another important forward fall-arrest capacity factor. The purpose of this study is to advance knowledge of this innovative and simple training program, FAST, integrated into fall prevention programming, to determine if it has potential to improve the physical capacity to arrest a fall and reduce injury risk in older community-dwelling women. This proposed study will use novel lab-based energy absorption and strength measures, combined with functional measures of mobility and fall risk. Fall-arrest capacity changes after an intervention such as FAST have never been examined in older women. Research Goals and Objectives: The principal research questions of this study are: 1) Does the addition of FAST training lead to improvements in UE energy absorption during controlled and unexpected forward descents as compared to a Standard fall prevention exercise program (Standard Exercise) focusing on walking, balance and lower extremity strength? 2) Does FAST produce greater gains in functional arm muscle strength, response time, mobility and balance control compared to Standard Exercise? The hypotheses are that FAST will result in greater improvements in energy absorption, UE strength, response time and mobility compared to Standard Exercise at the end of 12 weeks of training with similar gains in fall risk and balance control. Trial Design and Methodology: The proposed study is a pilot randomized trial where women, age 60 years or older living in the community will be randomly assigned to either FAST or Standard Exercise. Education on fall prevention will be provided to both groups. The exercise groups will be offered in the community, coordinated with an existing fall prevention program (Staying on Your Feet; Saskatoon Health Region). Participants will be recruited via announcements and posters in the community. Interested participants are invited to attend an information session prior to the start of the program and a screening questionnaire will be administered in person or by telephone. Eligibility criteria is explained in detail elsewhere. Eligible participants will be randomly assigned to either group using a random allocation conducted by someone not directly involved in the study. Measures will be collected at the College of Kinesiology Biomechanics of Balance and Movement Lab, University of Saskatchewan at the start of the training (baseline), and immediately post intervention. An experienced physical therapist or exercise therapist will supervise FAST and Standard Exercise. Both exercise programs will occur twice per week, 45 minutes duration, for 12 weeks at a community site. FAST will include the same exercises to improve balance, walking and general mobility as Standard Exercise, but will also incorporate FAST training. Outcome Measures: Outcome measures are designed to inform five primary fall-arrest capacity variables: 1) energy absorption in controlled descent, 2) energy absorption in unexpected descent, 3) eccentric muscle strength, 4) concentric muscle strength, 5) UE response time and secondary measures of fall risk, joint range of motion and balance and are described in detail elsewhere. Analysis: Effect sizes for this study were estimated using variability data from our previous fall-arrest capacity work with young and older women and other published UE energy data. Our pilot data with older adults has shown a 20% higher energy absorption in adults who perform more UE training. A clinically meaningful increase in energy absorption is unknown. Based on our data, a 25% increase in the energy absorption will require 16 participants per group to detect differences at 80% power. Intention-to-treat analysis will be conducted using all participants assigned to intervention or control sites. A completer only analysis (based on attendance rates) will also be conducted. Repeated measures MANOVA tests will test for time and time\*group differences across the 12 week time period for the five primary variables: energy absorption in controlled an unexpected descent, concentric and eccentric arm muscle strength and UE reaction time as well as the secondary measures of joint mobility, balance and fall risk. Given the exploratory nature of this study, significance will be set at p\<0.05 for omnibus tests.