Change of direction assessment following anterior cruciate ligament reconstruction: a review of current practice and considerations to enhance practical application

Key points

1. 01Field-based CoD tests (shuttle run, co-contraction, carioca) show moderate-to-high reliability but rely only on completion time and cannot detect between-limb biomechanical deficits
2. 02Laboratory 3D motion analysis consistently identifies residual movement asymmetries and compensatory strategies at 9-12 months post-ACLr despite normal performance times
3. 03Failing a full return-to-sport test battery (including CoD, strength, and hop tests) is associated with a fourfold greater risk of secondary ACL rupture
4. 04Cutting angle, approach velocity, fatigue state, and planned-versus-unplanned conditions all substantially affect knee loading during CoD tasks and should be systematically varied during assessment
5. 05Limb symmetry index on performance time alone is insufficient; movement mechanics including knee angles, trunk position, and ground reaction forces must also be evaluated

How it was conducted

Design

Narrative review

Databases searched

MEDLINE, PubMed, and SPORTDiscuss, covering publications from 1970 to April 2019

Inclusion criteria

Original articles describing CoD characteristics in patients following primary ACLr (autograft or allograft); any age, sex, or activity level; any post-surgical timeframe; any CoD performance or movement outcome

Exclusion criteria

Systematic reviews, conference abstracts, case studies, other narrative reviews, and non-peer-reviewed studies

CoD test categories reviewed

Field-based tests (shuttle run, co-contraction, carioca, modified t-test) and laboratory-based tests (3D motion analysis during 45-90-degree cutting tasks)

Key outcomes examined

CoD performance time, limb symmetry index, kinematic and kinetic variables (knee valgus angle, ground reaction forces, joint moments), and association with secondary ACL injury risk

What they found

• ACLr group showed greater asymmetry in CoD times versus healthy controls for both planned (p=0.004) and unplanned (p=0.008) 90-degree cutting conditions, but the magnitude of the difference had a small effect size (0.4) (King et al.)
• 80% of athletes demonstrated significant knee valgus of more than 5 degrees on the involved limb during a 90-degree cutting task after full return to sport; 60% also showed this on the uninvolved limb (Clark et al.)
• ACLr players exhibited increased knee abduction angles (ACLr 3.8 degrees vs. control) and peak knee adductor moments (ACLr 1.33 N.m/kg vs. control 0.80 N.m/kg, p=0.004) during 45-degree sidestep cutting at 12 months post-ACLr (Stearns et al.)
• ACLr players showed increased lower extremity coupling variability versus healthy controls: hip rotation/knee abduction-adduction (p=0.04), hip flexion-extension/knee abduction-adduction (p=0.05), knee abduction-adduction/knee flexion-extension (p=0.01), and knee abduction-adduction/knee rotation (p=0.03) (Pollard et al.)
• RTS group performed better on co-contraction (p=0.010) and carioca (p=0.045) tests than non-RTS group; no difference was found for shuttle run (p=0.607) (Jange et al.)
• A performance cut-off of less than 11 seconds on the agility test was used as a discharge criterion; no independent association with future re-injury risk was shown, but athletes failing the full battery had fourfold greater re-injury risk (Kyritsis et al.)
• Shuttle run, co-contraction, and carioca tests showed moderate-to-high test-retest reliability (r=0.51-0.74) and correlation with isokinetic strength (r=0.46-0.75) and hop tests at 6 months post-ACLr (Kong et al.)
• ACLr group showed 10%, 17%, and 23% improvement in shuttle run, side step, and carioca test times respectively at 6 months post-surgery compared to pre-surgery values (p less than 0.01 to 0.001) (Keays et al.)

Limitations

• This is a narrative review without a systematic search or risk-of-bias assessment, so included studies may not represent the full evidence base
• Most studies reviewed are small, involve selected sport populations (predominantly soccer), and lack pre-injury baseline data, limiting generalizability
• Laboratory-based biomechanical assessments have high ecological validity concerns and are not feasible for routine clinical monitoring during rehabilitation
• No reviewed study directly demonstrated that passing a specific CoD test criterion reduces re-injury risk as an independent assessment, only as part of a multi-test battery

Why it matters

For patients

After ACL surgery, you may score normally on common agility tests even if your knee still moves in risky ways, so these tests alone should not be the sole basis for your clearance to return to sport.

For clinicians

Current field-based CoD tests are inadequate as standalone return-to-sport criteria; clinicians should incorporate progressive CoD assessment that varies angle, speed, fatigue, and decision-making demands alongside movement quality analysis, not just completion time.

For readers

This review highlights a critical gap between available CoD testing tools and the complex demands of multidirectional sport, calling for practically viable on-field protocols that assess both performance and movement mechanics across rehabilitation stages.