News & Insights · Sports Science & Physio
ACL reconstruction is one of the most common surgeries in basketball. Approximately one in three young athletes who return to sport following ACL reconstruction will suffer a second ACL injury. That reinjury rate has not moved meaningfully in decades.
The core problem is that return-to-play decisions have historically been made without adequate objective testing. Time since surgery, self-reported readiness, and basic single-leg hop tests have been the dominant tools — missing the subtle movement asymmetries that persist in a surgically repaired knee and represent real re-injury risk under explosive game demands.
Force plate technology is changing that. And in July 2025, the most targeted research yet on this problem — specific to basketball athletes, specific to force plate metrics, and specific to the final stages of post-operative rehabilitation — was published in the International Journal of Sports Physical Therapy.
The study was co-authored by Christopher S. Hart, the physical therapist in the Medical and Performance Department of the NBA's Detroit Pistons, alongside Elizabeth S. Chumanov, PhD, from the Sports Rehabilitation department at UW Health University Hospital.
The focus was precise: not whether force plates are useful in ACL rehabilitation generally — that is already established — but which specific jump tasks and which specific metrics best detect the asymmetries that matter for basketball-specific return-to-play clearance.
Forty-nine male high school and collegiate basketball athletes who had undergone primary ACL reconstruction were assessed using a dual force plate system during the final stages of rehabilitation. Three jumping tasks were assessed: the double-leg countermovement jump (DL-CMJ), the single-leg countermovement jump (SL-CMJ), and the single-leg repeat hop (SL-RH).
Participants were split based on isokinetic quadriceps peak torque limb symmetry index (LSI) — above or below the 90% threshold, which is the established benchmark in ACL rehabilitation as the minimum acceptable level of quadriceps strength symmetry for return-to-play clearance.
Statistically significant differences between groups were found on two of the three jump tasks — the DL-CMJ and the SL-RH — but not on the SL-CMJ. In the double-leg countermovement jump, five metrics showed significant differences including eccentric rate of force development, concentric impulse, and peak take-off force.
In the single-leg repeat hop, jump height showed a mean difference of -12.4 between groups and reactive strength index showed a mean difference of 13.3 — capturing the ability to rapidly absorb and redirect force between landings, which is central to basketball's repeated jumping demands.
Concentric impulse — the area under the force-time curve during the propulsive phase of a jump — emerged as the single most consistent metric across the study. It was the only variable that showed statistically significant between-limb differences across all three jump tasks tested.
The clinical implication is direct. A basketball player who clears a 90% limb symmetry index on a hop test can still carry a 20%+ deficit in concentric impulse that will affect their ability to safely generate and absorb force during in-game jumps. That deficit, if undetected, is a return-to-play risk.
One of the study's most practically important findings was the absence of significant differences during the single-leg countermovement jump — the test most commonly used in clinical practice. The SL-CMJ may not be sensitive enough to detect the asymmetries that persist in the final stages of ACL rehabilitation, particularly in athletes who have become skilled at compensating through altered technique.
This finding argues for a battery of jump tests, not a single test. The study's conclusion states explicitly that no single jump task captures the full picture of physical readiness for return to basketball after ACL reconstruction.
The practical implications for physiotherapists and S&C coaches working with basketball players post-ACLR are clear. Force plate testing should be integrated into the final stages of ACL rehabilitation — not just as a standalone assessment but as a monitoring tool that tracks asymmetry trends across multiple sessions.
A minimum battery of three jump tasks is warranted: a bilateral reactive task (DL-CMJ), a unilateral reactive task (SL-RH), and the SL-CMJ. Clearing on the SL-CMJ alone is not sufficient. Concentric impulse should be the primary metric tracked, given its consistent sensitivity across tasks.
A player can achieve 90% quad LSI while still showing a 20%+ concentric impulse deficit. Both gates need to be cleared, not just one.
A September 2025 systematic review in Cureus concluded that force plate metrics can reveal kinetic imbalances that precede both ACL injury and re-injury — but that predictive value depends on using multiple metrics within a multi-modal framework rather than relying on composite scores alone.
Research from OrthoSport Victoria and La Trobe University, published in the Journal of ISAKOS in August 2025, validated force plate testing in ACL reconstruction patients at nine months post-operatively, finding excellent test-retest reliability (ICC > 0.96).
The 2025 research makes the same argument from multiple directions: ACL return-to-play clearance in basketball requires objective, force-plate-informed data. Time and self-report are not enough.
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