Accidental Falls
Conditions
Keywords
Falls, Balance, Protective Stepping, Lateral Balance, Elderly
Brief summary
Falls and their consequences are among the major problems in the medical care of older individuals. The long-term goal of this research is to establish the efficacy of a scientifically grounded and mechanism-based therapeutic intervention for improving balance function and preventing falls in older people. When human balance is challenged, protective stepping is a vital strategy for preventing a fall during activities of daily life. Many older people at risk for falls have particular difficulties with successfully stepping sideways as a protective response to loss of balance in the lateral direction. We propose that age-related declines in lateral balance function through impaired protective stepping that precipitates falls, result from neuromechanical (NM) limitations in hip abductor-adductor (AB-AD) muscle strength (torque and power). Moreover, we hypothesize that these functional and NM impairments are reversible with combined high intensity induced step training (IST) and muscle strengthening.
Detailed description
Falls and their consequences are among the major problems in the medical care of older individuals. Some 30 percent of community dwelling people aged 65 years and older, and over 50 percent of those living in institutions fall each year. Among older adults, complications of falls are the leading cause of deaths due to injury and are the most common cause of nonfatal injuries and hospitalization for trauma. The total lifetime healthcare cost of fall-related injuries for the elderly have been projected to reach $85 billion by the year 2020. Even in the absence of injury due to falling, the tendency to lose balance among the elderly commonly results in an overall reduction in the level of physical activity, and to a decreased ability to satisfactorily function in social roles. Despite the contributions of multiple risk factors to age-related falls (e.g., environmental hazards, orthostatic hypotension, disorientation, sedation), it is well recognized that those who fall present greater impairments in neuromechanical (NM) factors than do older non-fallers. Aging changes in balance and gait associated with NM impairments have also been consistently found to be among the most important risk factors for falls. What is presently unresolved, however, is which among the age-associated NM impairments, altered balance and mobility functions are best associated with falls and responsive to interventions (training).
Interventions
OTHERPhysical Training Interventions
Subjects will be assigned to one of four training groups. Training will occur three times weekly for twelve consecutive weeks. The IST group will receive waist-pulls by a motorized machine to produce stepping. Subjects in the HST group will perform muscle resistance exercises. Subjects in the combined IST and HST will receive both IST and HST interventions. Participants in the SFR group will perform flexibility and relaxation exercises.
Sponsors
Northwestern University
VA Maryland Health Care System
University of Maryland, Baltimore
Study design
Allocation
RANDOMIZED
Intervention model
FACTORIAL
Primary purpose
PREVENTION
Masking
DOUBLE (Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
65 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
* 65 years of age or older * Body Mass Index in range of 18.5 to 30
Exclusion criteria
* Timed -Up-and-Go faster than 12 seconds (very low fall risk) * Persons advised by their doctor not to exercise * Evidence of any medical condition as determined by physician or results of blood test that would lead to increased risk of accident, injury or illness due to any aspect of proposed tests and interventions, including resistance training * Persons with history of brain, nerve or muscle disorder including Parkinson's disease, stroke, peripheral neuropathy or myopathy * Persons with reported hip or knee joint replacement in past 6 months * Persons with significant foot deformities or amputation as determined by a qualified medical professional * Persons with sedative medications including hypnotics, anxiolytic, opioids, neuroleptics, or sedating antidepressants * Persons using medications that pose a significant bleeding risks as determined by a qualified medical professional * Any significant functional limitation as determined by a score of zero on any of the six daily tasks of the Instrumental Activities of Daily Living Scale (IADL) that enable independent living in the community. The six functional items used are: A. Telephone, B. Shopping, C. Food Preparation, D. Housekeeping, E. Laundry, and F. Transportation * Non-ambulatory (unable to walk) * Persons using a gait device at all times in home environment * Cognitive impairment defined as Mini-Mental State Exam score \<24 * Persons with uncorrected vision limiting visual function or eye surgery in ast 6 months * Persons with uncorrected hearing impairment limiting daily activities or communication as determined by a qualified medical professional * Persons with major depression (Centers for Epidemiological Studies Depression Survey score \>16)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Hip Abductor Torque | At baseline and post-test at 3 months | Hip abductor torque at baseline and 3 months |
| Step Count | At baseline and post-test at 3 months | The number of balance recovery steps at balance tolerance threshold at baseline and 3 months |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Falls | Individual subject at 12 months post training | Analysis of fall history between falls in the year prior to enrollment and 12 months after training finished. |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Induced Step Training (IST) The IST group will receive waist-pulls in both the left and right lateral directions by a motorized pulling system to produce stepping.
Physical Training Interventions: Subjects will be assigned to one of four training groups. Training will occur three times weekly for twelve consecutive weeks. The IST group will receive waist-pulls by a motorized machine to produce stepping. Subjects in the HST group will perform muscle resistance exercises. Subjects in the combined IST and HST will receive both IST and HST interventions. Participants in the SFR group will perform flexibility and relaxation exercises. | 25 |
| Hip Strength Training (HST) The HST group will have muscle strength training, to include hip abduction (AB) and adduction (AD) resistance exercises.
Physical Training Interventions: Subjects will be assigned to one of four training groups. Training will occur three times weekly for twelve consecutive weeks. The IST group will receive waist-pulls by a motorized machine to produce stepping. Subjects in the HST group will perform muscle resistance exercises. Subjects in the combined IST and HST will receive both IST and HST interventions. Participants in the SFR group will perform flexibility and relaxation exercises. | 26 |
| Combined Induced Step and Hip Strength Training This training group consists of combined induced step training (IST) and hip AB-AD strength training (HST).
Physical Training Interventions: Subjects will be assigned to one of four training groups. Training will occur three times weekly for twelve consecutive weeks. The IST group will receive waist-pulls by a motorized machine to produce stepping. Subjects in the HST group will perform muscle resistance exercises. Subjects in the combined IST and HST will receive both IST and HST interventions. Participants in the SFR group will perform flexibility and relaxation exercises. | 25 |
| Standard Flexibility and Relaxation (SFR) The SFR group will perform a flexibility and relaxation program involving minimal-intensity exercises.
Physical Training Interventions: Subjects will be assigned to one of four training groups. Training will occur three times weekly for twelve consecutive weeks. The IST group will receive waist-pulls by a motorized machine to produce stepping. Subjects in the HST group will perform muscle resistance exercises. Subjects in the combined IST and HST will receive both IST and HST interventions. Participants in the SFR group will perform flexibility and relaxation exercises. | 26 |
| Total | 102 |
Baseline characteristics
| Characteristic | Hip Strength Training (HST) | Combined Induced Step and Hip Strength Training | Induced Step Training (IST) | Standard Flexibility and Relaxation (SFR) | Total |
|---|---|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 26 Participants | 25 Participants | 25 Participants | 26 Participants | 102 Participants |
| Age, Categorical Between 18 and 65 years | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Age, Continuous | 71.9 years STANDARD_DEVIATION 6.8 | 73.3 years STANDARD_DEVIATION 5.9 | 73.8 years STANDARD_DEVIATION 6.3 | 71.2 years STANDARD_DEVIATION 4.2 | 72.8 years STANDARD_DEVIATION 5.8 |
| Region of Enrollment United States | 26 participants | 25 participants | 25 participants | 26 participants | 102 participants |
| Sex: Female, Male Female | 16 Participants | 11 Participants | 16 Participants | 18 Participants | 61 Participants |
| Sex: Female, Male Male | 10 Participants | 14 Participants | 9 Participants | 8 Participants | 41 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk | EG003 affected / at risk |
|---|---|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — | — / — | — / — |
| other Total, other adverse events | 6 / 25 | 4 / 26 | 5 / 25 | 1 / 26 |
| serious Total, serious adverse events | 0 / 25 | 0 / 26 | 0 / 25 | 0 / 26 |
Outcome results
Primary
Hip Abductor Torque
Hip abductor torque at baseline and 3 months
Time frame: At baseline and post-test at 3 months
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Induced Step Training (IST) | Hip Abductor Torque | Post-Test (Hip Strength Torque/Power) | 0.52 Nm/kg-m | Standard Error 0.03 |
| Induced Step Training (IST) | Hip Abductor Torque | Baseline (Hip Strength Torque/Power) | 0.49 Nm/kg-m | Standard Error 0.04 |
| Hip Strength Training (HST) | Hip Abductor Torque | Baseline (Hip Strength Torque/Power) | 0.49 Nm/kg-m | Standard Error 0.02 |
| Hip Strength Training (HST) | Hip Abductor Torque | Post-Test (Hip Strength Torque/Power) | 0.61 Nm/kg-m | Standard Error 0.03 |
| Combined Induced Step and Hip Strength Training | Hip Abductor Torque | Baseline (Hip Strength Torque/Power) | 0.59 Nm/kg-m | Standard Error 0.04 |
| Combined Induced Step and Hip Strength Training | Hip Abductor Torque | Post-Test (Hip Strength Torque/Power) | 0.62 Nm/kg-m | Standard Error 0.05 |
| Standard Flexibility and Relaxation (SFR) | Hip Abductor Torque | Post-Test (Hip Strength Torque/Power) | 0.55 Nm/kg-m | Standard Error 0.03 |
| Standard Flexibility and Relaxation (SFR) | Hip Abductor Torque | Baseline (Hip Strength Torque/Power) | 0.0523 Nm/kg-m | Standard Error 0.03 |
Primary
Step Count
The number of balance recovery steps at balance tolerance threshold at baseline and 3 months
Time frame: At baseline and post-test at 3 months
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Induced Step Training (IST) | Step Count | Baseline Balance Recovery Steps | 1.63 steps | Standard Error 0.057 |
| Induced Step Training (IST) | Step Count | Post-Test Balance Recovery Steps | 1.14 steps | Standard Error 0.08 |
| Hip Strength Training (HST) | Step Count | Baseline Balance Recovery Steps | 1.55 steps | Standard Error 0.042 |
| Hip Strength Training (HST) | Step Count | Post-Test Balance Recovery Steps | 1.24 steps | Standard Error 0.12 |
| Combined Induced Step and Hip Strength Training | Step Count | Baseline Balance Recovery Steps | 1.67 steps | Standard Error 0.073 |
| Combined Induced Step and Hip Strength Training | Step Count | Post-Test Balance Recovery Steps | 0.97 steps | Standard Error 0.067 |
| Standard Flexibility and Relaxation (SFR) | Step Count | Baseline Balance Recovery Steps | 1.78 steps | Standard Error 0.065 |
| Standard Flexibility and Relaxation (SFR) | Step Count | Post-Test Balance Recovery Steps | 1.24 steps | Standard Error 0.099 |
Secondary
Falls
Analysis of fall history between falls in the year prior to enrollment and 12 months after training finished.
Time frame: Individual subject at 12 months post training
Population: Not all study participants completed the falls following. The falls follow up was removed late in the trial.
| Arm | Measure | Value (MEAN) |
|---|---|---|
| Induced Step Training (IST) | Falls | 0.39 #falls/person/year |
| Hip Strength Training (HST) | Falls | 0.27 #falls/person/year |
| Combined Induced Step and Hip Strength Training | Falls | 0.23 #falls/person/year |
| Standard Flexibility and Relaxation (SFR) | Falls | 0.88 #falls/person/year |