Correlations between isokinetic knee torques and single-leg hop distances in three directions in patients after ACL reconstruction

Abstract

Background When planning rehabilitation and conditioning for performance enhancement and a return to sports after anterior cruciate ligament reconstruction, identifying the elements of physical function associated with single-leg hop is important. The purpose of this study was to clarify the relationship between single-leg hop distances in three directions and knee extensor and flexor strengths at 6 months after reconstruction. Methods Participants were 47 patients taking part in training sessions for sports involving cutting, pivoting, and jump-landing 6 months after reconstruction using a hamstring tendon. Single-leg hop distances in 3 directions (anterior, lateral, and medial) and isokinetic concentric strengths of knee extension and flexion were assessed at an angular velocity of 60°/s and 180°/s. Simple regression analyses using Spearman’s rank correlation coefficient were performed to assess relationships between single-leg hop distances and knee strengths. Results In the involved limb, correlations between single-leg hop distances in 3 directions and knee strengths were significant (P < 0.01) and correlation coefficients ranged from 0.48 to 0.65. Correlation coefficients between all single-leg hop parameters and knee extension/flexion strengths at an angular velocity of 180°/s were greater than those of 60°/s. Conclusions In this cross-sectional study of patients who participated in sports training sessions that required jump-landings and cutting approximately 6 months after reconstruction using hamstring grafts, isokinetic knee flexor, and extensor torques were moderately to strongly associated with single-leg hop distances in lateral, medial, and anterior directions. Given these relationships, assessments and exercises for knee strength and single-leg hop distances should be planned.

Association Between Knee Extension Strength at 3 and 6 Months After Anterior Cruciate Ligament Reconstruction

“…The postoperative criterion-based rehabilitation protocol was conducted based on previous studies, 24,25 and all patients underwent the same protocol (Table 1). However, patients who underwent repair of the mid-posterior meniscus were not permitted to squat with the knee bent more than 90°until 3 months postoperatively.…”

“…For open-chain exercises, the patient was instructed to avoid repeated knee extension exercises with maximum resistance near the ankle in the range of 30°to 10°of knee flexion in the sitting position for 3 months postoperatively. 24 Until then, patients mainly performed closed kinetic chain exercises and proprioceptive training. Jogging was permitted after 3 months, and the speed and distance of jogging were gradually increased according to joint effusion, symptoms, and muscle strength.…”

Addition of anterolateral ligament reconstruction to primary anterior cruciate ligament reconstruction could benefit recovery of functional outcomes

“…Several systematic reviews and meta-analyses 17 , 49 , 50 reported that the addition of ALLR to ACLR improves tibial rotational stability compared with isolated ACLR. In addition, as the muscle force generation capacity could improve dynamic joint stability, muscle performance, such as muscle strength and activation, could positively affect SLHD 23 , 47 , 51 , 52 . In the present study, muscle strength and AT for the quadriceps and hamstrings were better in the combined ACLR and ALLR versus isolated ACLR group.…”

“…The testing order for limbs began with the uninvolved side. Patients performed up to 15 extension and flexion repetitions (concentric/concentric action mode) for each leg at 180°/sec while in an upright sitting position, with the maximal torque value recorded (Nm/kg) 23 , 24 . Flexor and extensor strengths were determined as the quadriceps and hamstring muscle strengths, respectively.…”

Association between landing biomechanics, knee pain, and kinesiophobia in athletes following anterior cruciate ligament reconstruction: A cross‐sectional study

“…The longest distance (cm) of the three trials was recorded. The ICC of the single measurement values of the surgical leg was in the range of 0.91‐0.99 30 . The distance was normalized by height (cm).…”