Exercise as it relates to Disease/The effects of strength training on older adults to reduce the risk of falling

A critical appraisal on the research paper ‘Effect of high-intensity Strength-training on Functional Measures of Balance Ability in Balance Impaired Older Adults’ by Jennifer A. Hess DC, MPH, PhD and Marjorie Woollacott PhD (2005).

What is the background to this research?
A fall is defined as a result of unplanned and unexpectedly ending up on the ground. Although most falls are classified as non-fatal, in older adults, falls can be fatal as the injuries can be life altering. Compared to younger people, a fractured hip in an older adult triples risk of mortality. This paper believes high-intensity strength-training will improve physiological balance as well as the perceived likelihood of falling over in community-dwelling older adults. The participant is working up to lifting their 1RM, lifting the heaviest weight for the individual in one go to cause fatigue of the muscles. The physical tests include the Timed Up and Go (TUG) and the Berg Balance Scale (BBS), both testing the ability the individual can move and complete short tasks without falling over or feeling unsteady on their feet. The Activities Specific Balance Confidence Scale (ABC) is a questionnaire style test where the individual answers questions based on their perceived risk of falling over.

Where is the research from?
This study was conducted at Oregon University. A strong scientific focus is evident at Oregon University with the Knight Campus being dedicated to research and accelerating scientific impact .Jennifer A. Hess and Marjorie Woollacott are the authors of the study and have published over 230+ research papers throughout their careers. Hess is an associate professor of research in occupational injury prevention at the University of Oregon. Woollacott has a PHD in neuroscience and her expertise is in the development of balance and factors leading to a loss in balance as ageing occurs. Both authors appear to be highly reputable with their education achievements and the consistent research into human physiology.

Northwest Health Foundation is a philanthropic fundraising company help fund this research. Therefore, there are no obvious biases relating to this research study as the funding has come from places not associated to the outcome of the research.

What kind of research was this?
The study was a non-randomised, quasi-experimental and delayed entry trial. There was a combination of within and between subject’s design as 4 participants were involved in the pilot trial as well as the official study trial (used within the exercise group). The methodology of research is a minority compared to alike studies, as most studies within this field are randomised control studies, such as Sherrington C & Tiedemann A (2015) and [https://www.sciencedirect.com/science/article/pii/S1469029215000801 Fleig et. al (2015)].

What did the research involve?
The control group did not exercise, and the experimental group were exercising in a 10-week high-intensity strength-training program. With the focus on 4 muscles/muscle groups; tibialis anterior, gastrocnemius and soleus, quadriceps, and hamstrings. Pre and post training tests from the TUG, BBS and ABC were conducted. Specific exercises using machines to target the muscles/muscle groups were used each week. The first week the participants exercised at 50% of their estimated 1RM. Then week 2 increased to 80% of their 1RM or increased slightly based on their tolerance levels. The instruction was to complete each exercise quickly within 6 seconds and at a consistence pace.

The methodology of this study is deemed appropriate. Hess and Woollacott based the exercise program from previous research based on beginning weight training which involves the use of repetition maximums by Lombardi. Welles et. al and Sipilä et.al stating the positive use of the 1RM concept when training older adults, with reports of low to no injuries. The limitation of using individuals in the pilot-trial as well as the official trial can make the results appear untrustworthy. As it could be suggested that more than 10 weeks is needed to achieve the averages stated within the results in this study.

What were the basic results?
There was a significant difference correlated between strength in all lower extremity muscles post training compared to pre-training. The largest change in the results was the increase by 52% in strength of the gastrocnemius and soleus muscle. Across all experimental group participants, a 43% increase in overall muscle strength. There was little to no changes in the control group. The results are interpreted in a positive way, with every test on the intervention of exercise being statistically significant. However, there is no correlation between the improvement of the individuals due to exercise and actual falls rates. This is due to the study not doing a follow up on how the participants are post study and if any have had a fall since. This paper does recognise the limitations are over-emphasised in the results and could be a possibility due to the lack of information regarding if there were falls post study by the experimental group.
 * The TUG test was preformed quicker post training in the experimental group. the average for the control groups score increased, meaning it too longer to do the test. Originally the time taken to do the test was 11.5 seconds, post training it is 9.7 seconds, which correlated to a 20% decrease in risk of falling.
 * The BBS had a significant difference in the experimental group from post training with an increase in scoring, correlated to 16.8% decrease in likelihood of falling.
 * The ABC had a significant difference; post training results stated that 88.3% of individuals felt more confident in not falling after the exercise program.

What conclusions can we take from this research?
The study has found some highly valuable data relating to increasing balance and decreasing falls through high-intensity strength-training. There is no gold standard in assessing falls risk as an older adult, but the tests used within this study are all highly regarded especially the Activities-Specific Balance Confidence Scale as it has been shown to have reliability and validity, is a strength within the study. The results identified align with other strength-training studies including Sylliaas et. al from a 2011 study and in the 2013 study by Lee I & Park S, which both state the important of strength training in older adulthood to prevent falls. Although this study is from 2005, the results are still relevant. Potentially not viewed to the extent presented within this paper which leaves the reader questioning if the dosage of 10 weeks of strength-training will result in a decrease falls risk or if the duration needs to be longer? Due to the limitation in participant recruitment.

Practical advice
This advice is for those who have a moderate to low risk of falling:
 * Strength-training for older adults is beneficial to lower leg muscles and helps to decrease imbalance physically and the perception of falls risks. However, it is vital to contact your general practitioner prior to any exercise.
 * It is important to have a qualified trainer when exercising in strength training so they can assist in weight progression, technique, repetitions and sets and understand any medical conditions that the participants have, to tailor their program.

Further information/resources

 * WHO statistics on Falls
 * Australian physical activity guidelines for older adults
 * Introduction To Weights For Seniors - Youtube video
 * CDC: strength training for older adults; 'Growing Stronger' guide