An increase in ACLR limb loading occurred from 6 to 12 months post-ACLR, but this change is not affected by autograft source.
Key Findings
Results
ACLR limb peak impact force significantly increased from 6 to 12 months post-ACLR.
27 participants (20 female; 13 BPTB, 14 QT; age = 21.4 ± 6.1 years) were assessed at 6 ± 1 and 12 ± 2 months post-ACLR.
The increase in peak impact force on the ACLR limb was statistically significant (P = .007).
Average loading rate also significantly increased over time (P = .043).
Instantaneous loading rate on the ACLR limb also significantly increased over time (P = .021).
Assessments were conducted using force-sensing insoles in orthopaedic rehabilitation clinics.
Results
No significant changes were found in the contralateral (non-surgical) limb loading metrics over the same period.
Contralateral limb peak impact force, average loading rate, and instantaneous loading rate did not significantly change from 6 to 12 months.
This suggests the loading improvements were specific to the ACLR limb rather than a global change in gait.
Study used a prospective cohort design with gait assessment at two time points.
Results
Limb symmetry index (LSI) did not significantly change from 6 to 12 months post-ACLR for any loading variable.
Despite significant increases in ACLR limb loading metrics, the LSI (ratio of ACLR to contralateral limb) did not show significant improvement.
This finding suggests that while the ACLR limb improved in absolute loading, the relative symmetry between limbs did not statistically change over this period.
LSI was calculated for peak impact force, average loading rate, and instantaneous loading rate.
Results
No significant differences were found in the change in limb symmetry index between bone-patellar tendon-bone and quadriceps tendon autograft cohorts.
13 participants received BPTB autografts and 14 received QT autografts.
No differences in the change in LSI for any gait variable were found between graft cohorts.
Both graft types are extensor mechanism autografts, and this study specifically targeted this comparison.
The finding indicates autograft source does not significantly affect the trajectory of limb-loading symmetry recovery between 6 and 12 months.
Results
Participants experienced a significant improvement in IKDC score but not in ACL-RSI score from 6 to 12 months post-ACLR.
The International Knee Documentation Committee (IKDC) survey showed significant improvement over the study period.
The ACL-Return to Sport after Injury (ACL-RSI) score did not significantly improve over the same period.
Both patient-reported outcome measures were collected at 6 ± 1 and 12 ± 2 months post-ACLR.
The dissociation between IKDC and ACL-RSI improvement suggests physical function and psychological readiness to return to sport may recover at different rates.
Methods
The study used force-sensing insoles in a clinical environment to characterize limb-loading symmetry during walking gait after ACLR.
Force-sensing insoles were used as the measurement tool, enabling assessment in orthopaedic rehabilitation clinics rather than a laboratory.
Metrics captured included peak impact force, average loading rate, and instantaneous loading rate.
The prospective cohort study enrolled participants who underwent unilateral, primary ACLR.
The study was motivated by findings that up to 36% of patients develop osteoarthritis within a decade of ACLR, with postoperative gait changes associated with cartilage degeneration markers.
What This Means
This research suggests that people who have had ACL reconstruction (ACLR) surgery show meaningful improvements in how much weight they put through their surgically repaired leg during walking between 6 and 12 months after surgery. Specifically, the force and speed with which they loaded the repaired leg increased significantly over this period, which is generally a positive sign of recovery. However, the overall symmetry between both legs — meaning how evenly weight was distributed between the repaired and uninjured leg — did not significantly improve, suggesting that some asymmetry in walking gait may persist even as the repaired leg gets stronger.
This research also suggests that the type of tendon graft used to reconstruct the ACL — either from the patellar tendon (bone-patellar tendon-bone) or the quadriceps tendon — does not appear to influence how gait loading symmetry changes over this recovery period. Both graft types produced similar patterns of improvement, meaning surgeons and patients may not need to factor gait recovery differences into graft selection decisions. Additionally, while patients reported better knee function on a standard questionnaire (IKDC) by 12 months, their psychological readiness to return to sport (ACL-RSI) did not significantly improve, highlighting that physical and mental recovery may not progress at the same pace.
These findings matter because poor gait mechanics after ACL surgery have been linked to earlier development of knee osteoarthritis, which affects up to 36% of ACLR patients within 10 years. This research suggests that force-sensing insoles used in regular clinical settings — rather than specialized laboratories — can detect meaningful changes in how patients load their repaired leg, making this kind of monitoring more accessible. Understanding when and how gait recovers, and that graft type does not seem to alter that trajectory, could help clinicians better guide rehabilitation and return-to-sport decisions.
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Cherelstein R, Kuenze C, Walaszek M, Brumfield E, Lewis J, Moler C, et al.. (2026). A Graft Source Comparison of Changes in Walking Gait After Anterior Cruciate Ligament Reconstruction Using Force-Sensing Insoles.. Journal of athletic training. https://doi.org/10.4085/1062-6050-0245.25