Evaluation of Reactive Strength Index During Single-Limb Vertical Jumps and Isokinetic Strength Five to Eight Months After Anterior Cruciate Ligament Reconstruction.

Only twelve patients were followed, and no sample size or power calculation was done, so the study is too small to give precise estimates and cannot support analysis of subgroups. Everyone had the same operation from the same surgeon and the same rehabilitation at one hospital, so the results may not apply to patients with a different graft type, such as quadriceps or patellar tendon, or a different rehabilitation programme. Ages in the group ranged widely, from the early teens to the early fifties, and age was not taken into account, so the size of the correlations should be read cautiously. Reactive strength was measured with one phone or tablet application, so results could differ with other apps or devices. Home exercises, extra self-directed training and outside coaching were not recorded, so these may have contributed to differences in strength and jumping. Participants were told to keep ground contact time to a minimum, which may have pushed them to jump lower in order to land faster, so the reactive strength values may partly reflect the instruction rather than their physical capacity.

The text provided contains no funding statement and no conflict-of-interest declaration, so it is not possible to say who paid for the study or whether the authors had competing interests.

Do not conclude that reactive strength testing can replace isokinetic strength testing because of the strong correlations at five and seven months. This was an association in twelve patients at a single hospital, with no power calculation, and the relationship had disappeared by eight months.