Effects of Simultaneous Balance and Resistance Training on Strength, Power and Balance in Older Adults: A Stratified and Randomised Trial

Background:

In the course of aging, physical abilities gradually decline. Even though the cause of falls is assumed to be multifactorial, loss in muscle strength and balance control seems to be the most crucial intrinsic risk factors for falls.

Several meta-analysis and reviews emphasise positive effects of resistance, balance and combined exercise interventions on measure of strength, power and balance performance and thus on intrinsic (i.e., person-related) risk factors for falls. Pure balance as well as pure resistance training have been effective in improving postural control (e.g., gait measures, leg extension strength) and reducing risk of falling in elderly people. Combined resistance and balance training describes in general a sequential or concurrent training program, where resistance and balance exercises are executed in a consecutive order within the same training session. These exercise interventions have shown positive effects as well. Merging resistance and balance training, executing both simultaneously has not been investigated in regard to fall prevention in elderly people yet.

In the past 15 years, research of simultaneous resistance and balance training, so called 'instability resistance training' (IRT), has been grown. IRT utilises unstable devices (Swiss balls, BOSU® balls, wobble boards, etc.) and an external load (e.g., weights). This training modality has shown to affect core and lower limb muscle activation positively, improving balance and further having comparable gains in measures of strength analogue to traditional resistance training. Kibele and Behm, for example, found superior improvements in the single leg hop following an IRT in healthy young adults. They concluded in line with the principle of training specificity, that IRT induced higher balance adaptions, which were prominent in the balance demanding singe leg hop. Further, Behm and Colado recommended IRT for elderly people and there are studies investigating effects of different kinds of IRT on older adults. Granacher and colleagues examined effects of core instability strength training (CIT) on measures of trunk muscle strength, spinal mobility, dynamic balance and functional mobility in older adults. They found meaningful improvements in measures of strength, balance and mobility in comparison to a control group. Another study, investigating effects of a swiss ball exercise program on older adults, found positive effects on measures of physical fitness and balance in comparison to a control group. Based on used exercises, these studies focused on strengthening the core and improving mainly balance abilities. In a slightly different approach to improve balance in older women, Chulvi-Medrano and colleagues utilized a lower-limb training program using a unstable T-Bow® device. The training group improved in measures of dynamic, static and overall balance, whereas the control group experienced a decline or no change in balance abilities. All three aforementioned studies utilised unstable devices but none incorporated additional loads within their training programs, hence the resistance component of IRT is limited to bodyweight. Hence, there is a lack of literature supporting evidence for feasibility and effectiveness of IRT incorporating additional load as resistance to improve measures of strength, power and balance in elderly people.

To the investigators knowledge, no study has been conducted yet, investigating effects of IRT with additional load as resistance on risk factors for falls for elderly people.