Keywords:  Exercise prescription; bone health; lower limb loss

Why is this study important?

Previous research found those with lower limb amputations had reduced bone mineral density (BMD) at the hip (1). Lower hip BMD increases the risk of a hip fracture. Exercise interventions have been shown to improve BMD in other populations (2-4), but this has not been evaluated in a population with lower limb amputation previously. Before implementing any intervention, it may be helpful to obtain expert opinion designing an intervention prior to conducting a large clinical trial. 

This blog is based on a recent publication in the BJSM, found here (5).

How did the study go about this?

To obtain a consensus amongst a group of experts, using the Delphi method can allow participants to be asynchronous, anonymous from each other during the process, and minimise excessive influence from dominant voices (the bandwagon effect) (6,7     ). This study aimed to elicit expert opinion using the Delphi process and gain a consensus to define a viable exercise intervention to minimise hip BMD loss following traumatic lower limb amputation. To do this we provided experts with evidence-based statements regarding previous exercise interventions (split into sections on frequency, intensity, time, and type of exercise) and the potential application to individuals following an amputation. We required 70% or more of the experts to agree with a statement to gain a consensus. 

What did the study find?

This Delphi process recruited 13 world leading experts and used three separate rounds of rating evidence-based statements regarding the exercise programme.  All 13 experts completed rounds 1, 2 and 3 (100% completion). Round 1 excluded 12 statements and added 1 statement (11 statements for rounds 2–3). Round 3 reached consensus on nine statements to guide future exercise interventions. Experts agreed that exercise interventions should be performed at least 2 days per week for a minimum of 6 months, including at least three different resistance exercises at an intensity of 8–12 repetitions. Interventions should include weight-bearing exercises and involve high-impact (hopping, jumping) activities and be supervised initially.

What are the key take-home points?

This expert Delphi process achieved consensus on nine items related to exercise prescription to minimise hip BMD loss following traumatic lower limb amputation. As these findings were driven by best existing empirical evidence alongside leading expert opinion it could act as a current guide for best practice until future well-controlled experiments are completed in this population. These recommendations will be tested in a future feasibility trial to ensure this is acceptable to those with lower limb amputations, to ensure it is safe, and ensure we can recruit participants and that participants will adhere to the exercise programme. Consequently, we would plan to implement a full-scale clinical trial using this exercise programme to investigate if it can minimise bone mineral density loss after amputation and therefore, reduce lifelong fracture risk. 

Authors:

Blog by Fearghal Behan

References:

1. McMenemy L, Behan FP, Kaufmann J, et al. Association Between Combat-Related Traumatic Injury and Skeletal Health: Bone Mineral Density Loss Is Localized and Correlates with Altered Loading in Amputees: The Armed Services Trauma Rehabilitation Outcome (ADVANCE) Study. J Bone Miner Res 2023;38:1227–33.
2. Sibonga J, Matsumoto T, Jones J, et al. Resistive exercise in astronauts on prolonged spaceflights provides partial protection against spaceflight-induced bone loss. Bone 2019;128:112037
3. Fratini A, Bonci T, Bull AMJ. Whole Body Vibration Treatments in Postmenopausal Women Can Improve Bone Mineral Density: Results of a Stimulus Focussed Meta-Analysis. PLoS One 2016;11:e0166774.
4. Waugh EJ, Woodside DB, Beaton DE, et al. Effects of exercise on bone mass in young women with anorexia nervosa. Med Sci Sports Exerc 2011;43:755–63.
5. Behan FP, Bull AMJ, Beck BR, et al. Developing an exercise intervention to minimise hip bone mineral density loss following traumatic lower limb amputation: a Delphi study. British Journal of Sports Medicine 2024;58:1251-1257.
6. Junger S, Payne SA, Brine J, et al. Guidance on Conducting and REporting Delphi Studies (CREDES) in palliative care: Recommendations based on a methodological systematic review. Palliat Med 2017;31:684–706.
7. Page A, Potter K, Clifford R, et al. Prescribing for Australians living with dementia: study protocol using the Delphi technique. BMJ Open 2015;5:e008048.