SIB# 426- Jumping for Bone Strength
The Study: Mechanical Loading Increases Bone Material Strength in Postmenopausal Women-A 3-Month Intervention Study .
The Facts:
a. It is well known that bone adapts to loads.
b. It can do this in a number of ways including: “redistributing bone mass and altered geometry and microarchitecture.”
c. It is important to note the exclusion criteria for this study. The following people were not allowed to be in the study. “Exclusion criteria included a history of osteoporosis; regular weight-loading exercise (>1 time per week the last 3 months); current smoking; current or past (within 6 months) hormone-replacement therapy; fracture located at the ankle or lower leg; diseases or use of medication known to influence bone metabolism or fracture risk; and those who had initiated calcium or vitamin D supplementation in the preceding 6 months.”
c. In this study the authors looked at the effect of high impact exercise performed over a 3 month period on “bone material properties and microarchitecture in healthy postmenopausal women.”
d. The subjects performed one legged jumps done on a daily basis. They jumped on the same leg for the whole study.
e. The leg that they did not jump on was the control.
f. “The one-legged jumps were performed without shoes according to a protocol with a gradually increased frequency (week 1: 3x10 jumps/d; week 2: 3x15 jumps/d; weeks 3 to 6: 3x20 jumps/d; and weeks 7 to 12: 4x20 jumps/d). Participants were instructed to jump and land on the back of the foot without mitigating the shock in order to increase the impact and loading on the leg.”
g. The authors concluded that the one-legged jumps increased BMI [bone material strength index, which increased 7 percent.]. They found no changes in bone geometry or microarchitecture traits.
Take Home:
The bone material strength index increased 7 percent in the leg on which the subjects jumped.
Reviewer's Comments:
First take another look at the type of people who were not allowed to participate (excluded) in this study.
Bone strength is important, especially as we get older. This study showed an improvement in BMSI. It seems that this is something that would be of interest to a large group of people. I do want to note that I tried this exercise and it is not as easy to do as you might think and it was pretty jarring to me when I hit the floor “on the back of the foot without mitigating the shock in order to increase the impact and loading on the leg.” In addition to the types of people who were excluded from this study I had another concern. I wondered how this might affect the joints over time. This is an interesting article and I suggest that you read it, but be cautious about using this information for any recommendations you might make to your patients.
Reviewer: Roger Coleman DC
Editor: Mark R. Payne DC
Reference: Daniel Sundh,k Martin Nilsson, Michail Zojulakis et.al. High-Impact Mechanical Loading Increases Bone Material Strength in Postmenopausal Women-A 3-Month Intervention Study. J Bone Miner Res. 2018 Jul;33(7):1242-1251.
doi: 10.1002/jbmr.3431.Epub 2018 Apr 27.
Link to Abstract: https://pubmed.ncbi.nlm.nih.gov/29578618/
Link to Full Text: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6055617/pdf/JBMR-33-1242.pdf