A Systematic Review of Center of Mass as a Measure of Dynamic Postural Control Following Concussion.
Sarah Patejak, Joshua Forrest, Emily Harting and 2 others
PMID 34631243WHAT IT FOUND
Adding a mental task to walking exposed balance-control differences between concussed athletes and controls that walking alone missed, and those differences were still present after players were cleared to return.
Measuring this needs lab equipment most clinics lack, and all six included studies were small.
Key findings
01Differences in center-of-mass control between concussed and non-concussed people showed up mainly when a thinking task was added to walking, and the deficits persisted beyond the point where athletes were cleared to return to sport.
02In the one study that compared athletes with non-athletes, side-to-side sway was greater in athletes whether or not they had a concussion, so this measure may not identify concussion in that group.
03The review rests on six cohort studies of a narrow population, mostly high school and collegiate athletes aged 14 to 27, and none of the studies reported results by sex, which the authors say limits how far the findings extend.
STILL TO COME
How it was doneWhat they foundWhat it means for PTs
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What it does not show
Only six studies were included, all of them cohort designs, and the authors did not pool the results, so no overall size of effect can be quoted. The samples were small and narrow. Participants were aged 14 to 27, mostly high school and collegiate athletes, and none of the studies reported results by sex. The authors state this limits how far the findings apply beyond that group. There are no normative values or cut-off scores for center-of-mass sway after concussion, and no standard set of tests in use, so there is nothing to compare a patient's result against. Center of mass was measured with force plates, motion capture cameras or accelerometers, which the authors say most clinicians do not have and would need training to use. The quality scoring was weakest for bias, study size, statistical methods, participants, descriptive data and main results. Assessment time points varied widely across studies, from within 48 hours of injury to a one-year follow-up, and two studies did not state when the first assessment took place.
Declared interests
The authors state that none of them has a conflict of interest to report. The paper does not report a funding source.
The easy way to misread this
Do not read this as evidence that center-of-mass sway during walking is a clinical test you can use to decide when someone is ready to return to play. Every included study measured it with force plates, cameras or accelerometers, the review says this is not clinically feasible without that equipment and the training to interpret it, and no normative values or cut-off scores have been established. The evidence itself comes from six small cohort studies of young athletes.
Summarised by AI from the full paper, without a clinician reviewing it. Check it against the source before it changes what you do. Read it on PubMed →