Reducing Falls With RENEW in Older Adults Who Have Fallen
Condition: Muscle Atrophy; Physical Deconditioning
MeSH terms: Muscular Atrophy
Study type: Interventional

Summary: 
      This clinical trial will compare the effects of a high intensity Resistance Exercise via
      Negative Work (RENEW) vs. Traditional resistance exercise (TRAD) as part of a mult-component
      exercise and fall-reduction program on muscle conditioning; falling risks; as well as the
      fall incidence in older adults who have fallen. We anticipate that muscle conditioning will
      mediate the effect of RENEW on falling risks and fall incidence.
    

Detailed description: 
      Muscle atrophy and weakness accompanying aging contributes greatly to an increased risk and
      incidence of falling. Over one-third of individuals 65 years of age or older experience a
      fall [1,2]. In a 2006 review [3] of 16 controlled (prospective and retrospective) studies
      [4-8] major factors affecting risk were identified with the most influential risk factors
      being muscle weakness, and deficits in balance and gait. The rate of muscle de-conditioning
      is accelerated by inactivity, muscle disuse and co-morbid conditions [9-12]. Older
      individuals with deficits in muscle size, strength and power can become so mobility-limited
      that simply walking to the mailbox is at the upper limit of their physical capacity [9]
      Hence, improving the muscle conditioning of an elderly individual with high fall risk may
      decrease the risk and incidence of falls [13-18]. Muscle conditioning often requires
      considerable effort, yet many elderly individuals lack the energetic reserves required for
      high-intensity exercise. Consequently, both elderly women and men are caught in a
      "downward-spiral" as their muscle de-conditioning accelerates the myriad risks of falling and
      the incidence of life-threatening falls.

      We have explored the safety and feasibility of a high-intensity Resistance Exercise via
      Negative, Eccentrically-induced Work (RENEW) in multiple groups of de-conditioned elderly
      males and females, many characterized as being at-risk for a fall due to their impaired
      muscle condition, balance, mobility and confidence. Compared to traditional resistance
      exercise (TRAD), RENEW is novel and advantageous in that RENEW: is a high-intensity exercise
      for muscle, yet requires little effort (resulting in high levels of adherence); induces
      unprecedented muscle conditioning (size, strength and power); and lowers falling risks
      (balance, mobility and confidence) [19-23]. This study is unique and timely because it is
      unknown if RENEW's amplified muscle conditioning translates to a decreased incidence of
      falls, particularly for those at the highest risk for an injurious fall, i.e. those who have
      fallen. Further, RENEW's long-term sustainability has not been explored.

      This clinical trial will compare the effects of RENEW vs. TRAD as part of a multi-component
      exercise and fall-reduction program (MCEFRP) on muscle conditioning (muscle size, strength,
      power); falling risks (balance, mobility and confidence); as well as the fall incidence. We
      anticipate that muscle conditioning will mediate the effect of RENEW on falling risks and
      fall incidence. As well, the sustained benefit of RENEW will be explored.

      Objective #1: Test whether RENEW's effect is different than TRAD's effect on muscle
      conditioning, i.e., muscle size, strength and power.

      • H1a: RENEW will result in greater increases (relative to TRAD) in whole muscle volume,
      isometric strength and concentric power of the leg extensor muscles, specifically the
      quadriceps.

      Objective #2: Test whether the effects of RENEW on falling risks is mediated by muscle
      conditioning.

        -  H2a: RENEW will decrease falling risks (impaired balance, mobility and confidence) more
           than TRAD.

        -  H2b: RENEW's effects on falling risks will be mediated by greater muscle conditioning.

      Objective #3: Determine if RENEW lowers fall incidence more than TRAD.

      • H3a: The RENEW intervention will result in a lower fall incidence (falls and near falls)
      than TRAD via the direct influence on muscle conditioning and via the indirect influence of
      decreasing falling risks.
    

Intervention name(s): RENEW
Intervention type(s): Behavioral
Intervention description(s): RENEW will occur on a recumbent ergometer that appears like a normal stepper ergometer. While resisting the foot pedal movement the participant experiences eccentric muscle contractions about the knee and hip while performing negative work. The progression of the 3 x/week (every other day), 12 week RENEW program will be determined as a function of the rating of perceived exertion (RPE) using a "target" workload on the monitor. RENEW will be increased very slowly over the first 3 weeks and, subsequently, to maintain an 11-13 perceived exertion. During the formal RENEW training regimen the participants become fully acclimated to the device (week 3-4) the total RENEW load will increase weekly with no increase in their RPE.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Prevention
Keywords: Falling risk; muscle conditioning; muscle size; isometric strength; Incidence in falls