Motion Alterations After Anterior Cruciate Ligament Reconstruction: Comparison of the Injured and Uninjured Lower Limbs During a Single-Legged Jump

Abstract

Context: Asymmetries subsist after anterior cruciate ligament reconstruction (ACL-R), and it is unclear how lower limb motion is altered in the context of a dynamic movement.Objective: To highlight the alterations observed in the injured limb (IL) during the performance of a dynamic movement after ACL-R.Design: Cross-sectional study. Setting: Research laboratory. Patients or Other Participants: A total of 11 men (age ¼ 23.3 6 3.8 years, mass ¼ 81.2 6 17.0 kg) who underwent ACL-R took part in this study 7.3 6 1.1 months (range ¼ 6-9 months) after surgery.Intervention(s): Kinematic and kinetic analyses of a singlelegged squat jump were performed. The uninjured leg (UL) was used as the control variable.Main Outcome Measure(s): Kinematic and kinetic variables.Results: Jump height was 24% less for the IL than the UL (F 1,9 ¼ 23.3, P ¼ .001), whereas the push-off phase duration was similar for both lower limbs (P ¼ .96). Knee-joint extension (F 1,9 ¼ 11.4, P ¼ .009), and ankle plantar flexion (F 1,9 ¼ 22.6, P ¼ .001) were less at takeoff for the IL than the UL. The hip angle at takeoff was not different between lower limbs (P ¼ .09). We found that total moment was 14% less (F 1,9 ¼ 11.1, P ¼ .01) and total power was 35% less (F 1,9 ¼ 24.2, P ¼ .001) for the IL than the UL. Maximal hip (P ¼ .09) and knee (P ¼ .21) power was not different between legs. The IL had 34% less maximal ankle power (F 1,9 ¼ 11.3, P ¼ .009) and 31% less angular velocity of ankle plantar flexion (F 1,9 ¼ 17.8, P ¼ .004) than the UL.Conclusions: At 7.3 months after ACL-R, motion alterations were present in the IL, leading to a decrease in dynamic movement performance. Enhancing the tools for assessing articular and muscular variables during a multijoint movement would help to individualize rehabilitation protocols after ACL-R.Key Words: knee, dynamic movement, hop test, rehabilitation Key PointsKinematic and kinetic alterations were demonstrated in the injured leg at 7.3 months after anterior cruciate ligament reconstruction. These alterations led to decreased jump height during a single-legged squat jump in the injured leg. Enhancing tools for assessing articular and muscular variables during a multijoint movement would help to individualize rehabilitation protocols after anterior cruciate ligament reconstruction.

Evaluation of portable accelerometers and force platforms as clinically feasible instrumented outcome measures

“…We report LSIs in this study ranging between 67% and 74%, depending on the method of scoring. This asymmetry is similar to previous studies for vertical hopping that report LSIs ranging between 74% and 76% at a similar time point after ACLreconstruction (de Fontenay et al, 2014, Gustavsson et al, 2006, Petschnig et al, 1998. Furthermore, these values were lower (i.e., greater asymmetry) than LSIs reported for horizontal hopping (Gustavsson et al, 2006, Thomee et al, 2012, Petschnig et al, 1998.…”

“…Because its slats are at half inch intervals, this method lacks precision for detecting between-limb differences in height when compared to other methods. This is especially true for detecting differences in single limb hop height, where the height for most individuals is less than 10 inches (Gustavsson et al, 2006, Ageberg et al, 2008, de Fontenay et al, 2014. The jump and reach method used with the Vertec also lacks accuracy compared to other methods like contact mats and force platforms (Leard et al, 2007).…”

“…The single leg vertical hop possesses high test-retest reliability (Gustavsson et al, 2006) and is also among the most sensitive tests for detecting between-limb differences in performance after ACL reconstruction (Petschnig et al, 1998, Thomee et al, 2012. Differences in single leg hopping for height are common after rehabilitation from anterior cruciate ligament (ACL) reconstruction is typically complete (Petschnig et al, 1998, de Fontenay et al, 2014, Ernst et al, 2000, Thomee et al, 2012. Because they are novel tasks, hop testing for distance and hop testing requiring repeated hops lacks functional relevance for many people.…”

Asymmetry of Inter-joint Coordination during Single Leg Jump after Anterior Cruciate Ligament Reconstruction

“…In line with previous studies [36,38,40], the first group included 12 males who had undergone unilateral bone-patellar-tendon-bone autograft ACL-R after isolated ACL injury. The surgeries were performed by 2 experienced surgeons from the same orthopedic department.…”

“…For instance, during the push-off phase of a single-leg jump, some studies observed a smaller range of motion of the knee [38], ankle and hip [39] for IL in comparison to NIL. From a mechanical point of view a lower ankle [40] and knee joint power [38] was observed for IL in comparison to NIL. Although these studies gave insights about the lower limb asymmetries after ACL-R, each joint was assessed independently.…”