scholarly journals STRONGER THAN EVER! ADOLESCENT ATHLETES SHOW STRENGTH GAINS WITHIN THE UNINJURED LEG AFTER ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION

2021 ◽  
Vol 9 (7_suppl3) ◽  
pp. 2325967121S0005
Author(s):  
Elliot Greenberg ◽  
Joshua Bram ◽  
Theodore Ganley

Background: The restoration of quadriceps strength after anterior cruciate ligament reconstruction (ACLR) is critical to restore optimal patient function and reduce the incidence of secondary ACL injury. Strength is typically quantified during return to sport assessments, by comparing the strength in the involved limb to that of the uninvolved limb. A limb symmetry index (LSI) is calculated and used to determine if any residual strength deficits persist. Recent evidence demonstrates that the uninvolved limb may lose strength during ACLR recovery and suggests that pre-operative uninvolved limb strength values may offer a better representation and more stringent indicator of strength recovery after ACLR. However, this body of literature is limited and no studies have specifically evaluated this occurrence within youth athletes. Purpose: To evaluate the change in strength in the uninvolved limb from pre-operative to 6 months post-ACLR, and assess the effect of pre-operative strength comparison on 6-month post-op LSI. Methods: A retrospective cohort analysis of pediatric patients (≤18 years) undergoing primary ACLR from 1/2018-1/2020 without concomitant multi-ligamentous reconstruction was conducted. Isokinetic peak torque values for the uninvolved and involved quadriceps were extracted at pre-operative (uninvolved only) and 6 months post-operative. Strength changes were analyzed using paired-samples t-test. Results: Complete data was available for a total of 17 subjects (mean age 15.1±1.7, 53% female). Pre-operative strength assessment was performed a mean of 11.5 days (range 1-26) prior to surgery. The mean 6-month post-operative assessment occurred at 177 days (range 127-246). The uninvolved limb was significantly stronger (p<0.001) at 6 months compared to preoperatively, with a mean improvement of 12.1ft/lbs (95%CI 18.3 – 7.2) with a change from 82.4ft/lbs to 95.1 ft/lbs. The LSI was calculated using both pre-operative and 6-month post-operative uninvolved limb values and demonstrated substantially lower LSI values when using concurrent 6-month data (LSIpre 91.3% vs LSI6M 76.9%). Conclusions: Among this sample, the uninvolved limb got stronger during post-ACLR recovery and comparison to concurrently assessed strength values led to a more stringent determination of LSI. Differences in rehabilitation programming, adolescent physiology, and pre-injury training patterns may explain why these results differ than those found in older cohorts.

2018 ◽  
Vol 53 (4) ◽  
pp. 347-354 ◽  
Author(s):  
Alexa K. Johnson ◽  
Riann M. Palmieri-Smith ◽  
Lindsey K. Lepley

Context:  To quantify quadriceps weakness after anterior cruciate ligament reconstruction (ACLR), researchers have often analyzed only peak torque. However, analyzing other characteristics of the waveform, such as the rate of torque development (RTD), time to peak torque (TTP), and central activation ratio (CAR), can lend insight into the underlying neuromuscular factors that regulate torque development. Objective:  To determine if interlimb neuromuscular asymmetry was present in patients with ACLR at the time of clearance to return to activity. Design:  Cross-sectional study. Setting:  Laboratory. Patients or Other Participants:  A total of 10 individuals serving as controls (6 men, 4 women; age = 23.50 ± 3.44 years, height = 1.73 ± 0.09 m, mass = 71.79 ± 9.91 kg) and 67 patients with ACLR (43 men, 24 women; age = 21.34 ± 5.73 years, height = 1.74 ± 0.11 m, mass = 77.85 ± 16.03 kg, time postsurgery = 7.52 ± 1.36 months) participated. Main Outcome Measure(s):  Isokinetic (60°/s) and isometric quadriceps strength were measured. Peak torque, TTP, and RTD were calculated across isometric and isokinetic trials, and CAR was calculated from the isometric trials via the superimposed burst. Repeated-measures analyses of variance were used to compare limbs in the ACLR and control groups. Results:  No between-limbs differences were detected in the control group (P &gt; .05). In the ACLR group, the involved limb demonstrated a longer TTP for isokinetic strength (P = .04; Cohen d effect size [ES] = 0.18; 95% confidence interval [CI] = −0.16, 0.52), lower RTD for isometric (P &lt; .001; Cohen d ES = 0.73; 95% CI = 0.38, 1.08) and isokinetic (P &lt; .001; Cohen d ES = 0.84; 95% CI = 0.49, 1.19) strength, lower CAR (P &lt; .001; Cohen d ES = 0.37; 95% CI = 0.03, 0.71), and lower peak torque for isometric (P &lt; .001; Cohen d ES = 1.28; 95% CI = 0.91, 1.65) and isokinetic (P &lt; .001; Cohen d ES = 1.15; 95% CI = 0.78, 1.52) strength. Conclusions:  Interlimb asymmetries at return to activity after ACLR appeared to be regulated by several underlying neuromuscular factors. We theorize that interlimb asymmetries in isometric and isokinetic quadriceps strength were associated with changes in muscle architecture. Reduced CAR, TTP, and RTD were also present, indicating a loss of motor-unit recruitment or decrease in firing rate.


2013 ◽  
Vol 20 (1) ◽  
pp. 13-18 ◽  
Author(s):  
Marta Jarocka ◽  
Adam Czaplicki

AbstractIntroduction. The number of arthroscopic reconstructions of the anterior cruciate ligament (ACL) has been increasing not only among competitive athletes, but also among recreational athletes. The monitoring of the rehabilitation process in order to determine a safe time to return to the pre-injury activity is thus of great practical importance. The aim of this paper is to analyse the changes in selected biomechanical variables which occur after the therapeutic training following an anterior cruciate ligament reconstruction. Materials and methods. Twenty nine males (age 27.3 ± 5.7 years) after the anterior cruciate ligament reconstruction participated in the study. A quadruple-stranded semitendinosus/gracilis graft was used for the reconstruction. The biomechanical evaluation of the rehabilitation process was provided by an isokinetic dynamometer Biodex System Pro-3 working at speeds of 60 deg/s and 180 deg/s during testing the knee extensor and flexor muscles. In the case of an injured limb, the absolute peak torque, relative peak torque, average power and hamstring/ quadriceps (H/Q) ratio were determined. In addition, the values of flexor and extensor torques for healthy and injured limbs were compared. The study was carried out in four stages: before the surgery, three, six and twelve months after the surgery. Results and analyses. The results showed significant differences in each value between various stages of the biomechanical rehabilitation process of the knee. The applied therapeutic training influenced significantly the changes in the values of the tested variables. The results have confirmed that the biomechanical measurements can be treated as a supplementation to the clinical evaluation of the patient after ACL reconstruction. They may also be used for the optimisation of the therapeutic training.


2019 ◽  
Vol 131 (3) ◽  
pp. 619-629 ◽  
Author(s):  
Faraj W. Abdallah ◽  
Jorge Mejia ◽  
Govindarajulu A. Prasad ◽  
Rebecca Moga ◽  
Jaskarandip Chahal ◽  
...  

Abstract Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New Background The ideal location for single-injection adductor canal block that maximizes analgesia while minimizing quadriceps weakness after painful knee surgery is unclear. This triple-blind trial compares ultrasound-guided adductor canal block injection locations with the femoral artery positioned medial (proximal adductor canal), inferior (mid-adductor canal), and lateral (distal adductor canal) to the sartorius muscle to determine the location that optimizes postoperative analgesia and motor function. The hypothesis was that distal adductor block has (1) a superior opioid-sparing effect and (2) preserved quadriceps strength, compared with proximal and mid-locations for anterior cruciate ligament reconstruction. Methods For the study, 108 patients were randomized to proximal, mid-, or distal adductor canal injection locations for adductor canal block. Cumulative 24-h oral morphine equivalent consumption and percentage quadriceps strength decrease (maximum voluntary isometric contraction) at 30 min postinjection were coprimary outcomes. The time to first analgesic request, pain scores, postoperative nausea/vomiting at least once within the first 24 h, and block-related complications at 2 weeks were also evaluated. Results All patients completed the study. Contrary to the hypothesis, proximal adductor canal block decreased 24-h morphine consumption to a mean ± SD of 34.3 ± 19.1 mg, (P &lt; 0.0001) compared to 64.0 ± 33.6 and 65.7 ± 22.9 mg for the mid- and distal locations, respectively, with differences [95% CI] of 29.7 mg [17.2, 42.2] and 31.4 mg [21.5, 41.3], respectively, mostly in the postanesthesia care unit. Quadriceps strength was similar, with 16.7%:13.4%:15.3% decreases for proximal:mid:distal adductor canal blocks. The nausea/vomiting risk was also lower with proximal adductor canal block (10 of 34, 29.4%) compared to distal location (23 of 36, 63.9%; P = 0.005). The time to first analgesic request was longer, and postoperative pain was improved up to 6 h for proximal adductor canal block, compared to mid- and distal locations. Conclusions A proximal adductor canal injection location decreases opioid consumption and opioid-related side effects without compromising quadriceps strength compared to mid- and distal locations for adductor canal block in patients undergoing anterior cruciate ligament reconstruction.


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