Exercise as it relates to Disease/Progressive resistance training improves gait initiation in individuals with Parkinson's disease

This aim of this article is to critique a study titled "Progressive resistance training improves gait initiation in individuals with Parkinson's disease", investigating the effects of resistance training on gait in individuals with Parkinson's disease.

Background to this research
This study investigated the effects of progressive resistance training (PRT) on the gait initiation of individuals afflicted with Idiopathic Parkinson’s disease (IDP). Prior to the conduction of this study, there had been few randomized controlled trials evaluating the effectiveness of resistance training. More prominently, this is the first study of its kind to evaluate the effects of PRT on gait initiation. The importance of this research is evident through the opportunity it offers to individuals afflicted with IDP to improve their quality of life through the demonstration of the effectiveness of a potential intervention.

Where is this research from
This research was conducted by professionals from 4 prestigious institutions including the University of Florida, Georgia Southern University, Columbia university and the Mount Sinai School of Medicine. It was published on Elsevier, a global information analytics business on the 21st of December in 2011. This study included an important exclusion criterion regarding the selection of participants. The participants were required to have no history of, or ongoing cardiovascular, musculoskeletal, vestibular or other neurological conditions. This is to ensure the results were not skewed as a result of these afflictions. The research was published through an independent entity. This removes the risk of any potential bias from sponsors or organisations that may benefit from the results of this investigation, in addition, the paper includes a statement from the authors declaring that there are no conflicts of interest.

What kind of research was this
This study was a randomized control trial. So far it is the only one of its kind to investigate the effects of PRT on gait initiation within Parkinson’s patients. However, multiple studies have evaluated the effectiveness of PRT as an intervention for improving qualities of life in other areas. For instance an investigation conducted by Leland E. Dibble PhD, Tessa F. Hale BS, Robin L. Marcus PhD, John Droge MS, J. Parry Gerber PhD, Paul C. LaStayo PhD investigated the effects of resistance training on functional gains in patients with Parkinson’s disease. The variables included muscle volume, muscle torque, mobility task performance etc. Both studies involved controlled selection of participants subject to exclusion criteria and involved independent variables as well as a control group. The levels of evidence do not differ between studies as although the overarching aims of the investigations are different, both demonstrate PRT as an effective intervention to improve quality of life in individuals with Parkinson’s disease.

What did the research involve
This study involved a select group of 18 individuals afflicted with IDP. The participants first undertook 5 repeat trials of gait initiation, from which the results were recorded. Following this, participants were randomly assigned to a PRT group or a control group. Those assigned to the PRT then conducted two sessions of 1 repetition maximum testing, separated by 72 hours, for knee extension and knee flexion-based exercises. The initial load for exercises was set at 70% of 1RM. The PRT intervention consisted of 2 rounds of 6 exercises with 12-20 repetitions and 5 minutes rest between circuits. These exercises included: seated leg press, knee extension, knee flexion, abdominal curl, back extension, seated calf raise and multi directional ankle mobility exercises. A minimum of 18 sessions were completed by each participant over a 10-week period. 1RM testing was conducted once more at the end of the trial period and variables of interest were re-calculated. The methodology applied to this investigation took adequate measures to ensure reliability and validity were maintained throughout the 10-week period. The pre-screening and exclusion criteria for participants effectively ensured that the data collected was not subject to any bias from additional unforeseen variables. In addition, all processes conducted throughout the investigation, such as 1RM testing which included 2 repeat trials and pre-intervention gait initiation which included 5 repeat trials for each participant. Furthermore, the investigation included a control group who did not undertake a PRT program, thus ensuring the results could not be attributed to other factors. In terms of validity, the investigation distinguishes clear variables to be assessed such as displacement of centre of pressure and initial stride length, both common variables in a biomechanical analysis of gait initiation (GI). The re-testing of these variables post intervention demonstrates that the investigation effectively examines PRT as a means of improving GI. Finally, as stated above, the results from this randomized control trial are consistent with similar studies that examine the effectiveness of PRT as an intervention. Despite this, the study involved only a small group of participants. A larger group of participants would improve the reliability of this investigation. Further limitations to this study include a lack of 1RM testing from the control group as well as the use of only 1 specific rep range for the prescribed exercises. The addition of more groups of participants may have allowed for an investigation into the benefits of higher intensity exercise.

What were the basic results
The results from this research indicated that PRT serves as an effective intervention for increasing GI in individuals with IDP 29% performance increase was observed in displacement of centre of pressure, an 11% increase was noted in stride length, knee extension 1RM strength increased by 76% and knee flexion 1RM strength increased by 57%. No changes in performance were observed in the control group. The researches therefore established a strong correlation between PRT and improvement of physical functionality, quality of life and gait speed and initiation. The authors own implications of this research are succinct and include limitations of the paper. As such, the implications do not appear over-emphasized.

What conclusions can take from this research
My personal insights regarding this paper do not differ from those of the authors. Having conducted extensive past research of the benefits of PRT in other areas in addition to comparing these findings with those of other studies I strongly agree with the conclusions drawn from this investigation. The study under examination was conducted in 2011, however, more recent studies, such as a two‐year randomized controlled trial of similar nature conducted in 2013 and an investigation into non-pharmacological treatments for this disease which examined PRT also produced similar results.

Practical applications
This evidence establishes the importance of resistance training not only in patients with IDP but also those at risk of developing the disease. Furthermore, this research highlights specific exercises necessary for effective results in addition to providing parameters that can be used to measure the progress of individuals. Given this, establishments that cater to the needs of patients with IDP such as aged care facilities should take measures to raise awareness for PRT as a potential intervention. However, individuals must be subjected to industry standard pre-screening and risk assessments prior to the commencement of an exercise program.

Further resources
Further reading on this subject may be beneficial to both individuals afflicted with IDP as well as aged care workers attempting to encourage physical activity within elderly populations. These sources do not substitute professional medical advice.

For individuals afflicted with IDP:

https://www.parkinsons.org.au/

https://www.inspireeducation.net.au/blog/parkinsons-services-and-resources-for-patients-and-carers-in-australia/

For aged care workers:

https://www.wikihow.com/Encourage-Independence-in-Clients-in-Residential-Care

https://www.betterhealth.vic.gov.au/health/healthyliving/physical-activity-for-seniors