Alef Cavalcanti Matias de Barros

Purpose: To evaluate bilateral isokinetic performance symmetry of knee extensors and flexors 6 months after anterior cruciate ligament reconstruction using a rectus femoris tendon autograft. Methods: This retrospective case series included patients consecutively recruited at a single tertiary sports medicine center between January 2023 and July 2024. Inclusion required primary anterior cruciate ligament reconstruction with a rectus femoris autograft, no prior knee surgeries, and a minimum 6‐month follow‐up; patients with revision or multiligamentous procedures were excluded. Isokinetic testing was performed at 6 months using a computerized dynamometer. The nonoperative limb was tested first, followed by the operative limb. Patients performed 5 maximal effort trials at 60°/s for both extension and flexion. Measured outcomes included peak torque (PT), PT normalized to body weight, angle at PT, total work (TT), and mean power (PM) for both knee extension and flexion. Paired t‐tests compared operated and nonoperated limbs. Statistical significance was set at P ≤ .05. Results: Thirty‐one male patients (mean age, 26.3 ± 4.7 years) were included, with a mean follow‐up of 6.2 ± 0.4 months. At 6 months, the operated limb achieved 71% of contralateral PT and 75% of contralateral PM, with significant deficits in extension PT ( P < .001), PT normalized to body weight ( P < .001), TT ( P < .001), and PM ( P = .002), while no significant difference was found for angle at PT ( P = .457). Flexor performance showed near‐complete recovery, with the operated limb reaching 93% of contralateral peak torque and 90% of TT, with P = .355, .340, .902, .153, and .316 for PT, PT normalized to body weight, angle at PT, TT, and PM, respectively. Conclusions: At 6 months, anterior cruciate ligament reconstruction with a rectus femoris autograft was associated with complete recovery of knee flexor performance but persistent deficits in knee extensor performance. Level of Evidence: Level IV, retrospective case series.

Purpose: To compare isokinetic quadriceps performance 6 months after anterior cruciate ligament reconstruction (ACLR) using rectus femoris (RF) versus hamstring tendon (HT) autografts. Methods: In this cross‐sectional study, 75 male patients who underwent primary ACLR with RF ( n = 31) or HT ( n = 44) autografts were evaluated ~6 months postoperatively. Bilateral isokinetic testing at single angular velocity 60°/s (Biodex Multi‐Joint System 4) measured peak torque (PT), PT normalized to body weight (PT/BW), angle at peak torque (aPT), total work (TW), and mean power (PM). Between‐group comparisons used independent t‐tests; paired comparisons were conducted within the RF group. Results: No between‐group differences were detected for PT, PT/BW, aPT, TW, or PM ( p > 0.05 for all—primary contrast PT: mean diff. 5.3 Nm; 95% CI –20.4 to 30.9; p = 0.689). Within the RF group, the operated limb showed lower PT, PT/BW, TW, and PM than the contralateral limb (all p ≤ 0.002), with no difference in aPT. Conclusions: At 6 months after ACLR, quadriceps performance did not differ between RF and HT autografts. These early data do not address return‐to‐sport timing or graft healing and should not be interpreted as evidence of equivalence (it is not powered for equivalence/non‐inferiority); rather, they support RF as a potential option warranting longer‐term studies incorporating functional tests and patient‐reported outcomes. Level of Evidence: Level III, cross‐sectional comparative study.

This study investigated additional and traditional variables from isokinetic test of thigh muscles in soccer players across different field positions. One hundred and eighty-nine athletes performed maximal concentric isokinetic knee contractions on dominant (DL) and non-dominant limb (NDL) at 60o/s and 240o/s. The additional outcomes peak torque angle (AngPT), acceleration time (AcT) and time to peak torque (TPT) and traditional outcomes Peak torque (PT), total work (TW) and power (Pw) were extracted from the exam. Goalkeepers (GK), side backs (SB), central backs (CB), central defender midfielders (CDM), central attacking midfielders (CAM) and forwards (FW) were considered. Comparisons between limbs and positions demonstrated that SB extensors of the DL presented TPT lower (p = 0.006) and AngPT higher (p = 0.011) than NDL at 60 degrees/s. CDM extensors of the DL showed lower TPT at 60 degrees/s (p = 0.003) and 240 degrees/s (p = 0.024). CAM flexors of the DL showed lower TPT (p = 0.026) and AcT (p = 0.021) at 240 degrees/s than NDL. CB, CDM and CAM extensors of the NDL showed higher PT, TW and Pw than DL (p < 0.05). In conclusion, there are muscle imbalances between limbs in SB, CDM and CAM and across different field positions.

Purpose: This study aimed to assess skin temperature (Tsk) changes after different magnitudes of exercise-induced muscle damage (EIMD) of the elbow flexor muscles and investigate whether Tsk is related to indirect markers of EIMD. Methods: Thirty healthy active men were randomly allocated to the mild (MiDG) (n = 15) or moderate (MoDG) (n = 15) muscle damage group. Muscle damage in elbow flexor muscles was induced by 10 (for MiDG) or 30 (for MoDG) maximal eccentric isokinetic contractions at 60 degrees/s. Tsk, maximal voluntary isometric contraction (MVIC), delayed-onset muscle soreness (DOMS), plasma creatine kinase (CK) activity, range of motion (ROM), and pressure pain threshold (PPT) were measured before and up to 72 hr after EIMD. Results: Tsk increased only immediately after EIMD (p < .05; f = 1.44) in the MoDG (4.2%) and MiDG (4.6%), returning to near baseline values 30 min after EIMD and remaining so thereafter. In addition, there was no intergroup difference (p > .05) at any of the times analyzed, or correlation between Tsk and most indirect markers of EIMD. Conclusions: In conclusion, Tsk should not be considered an indirect marker of mild or moderate muscle damage in active men, since alterations in this variable last less than 30 min after damaging exercise and showed no correlation with most indirect markers of EIMD.

The use of strategies to assure better post-effort recovery is frequent in sports settings. There are several interventions available for exercise induced muscle damage recovery, but cold-water immersion (CWI) stands out among them. The effects of CWI are unclear in the literature and, although the number of street runners has been growing, there is a gap in the scientific evidence regarding the use of CWI to recover runners’ performance after a 10-km street run. Purpose: The goal of our study was to analyze the effects of CWI on the recovery of muscle damage markers after a 10-km street run. Method: We randomly assigned thirty male recreational street runners, immediately after a 10-km street run, into three recovery groups: control (rest for 10 minutes), immersion (10 min immersed in water without ice at room temperature) and CWI (10 min immersed in water with ice at 10ºC). We assessed pain, triple hop distance, extensor peak torque and blood creatine kinase levels pre- and post-run, post-intervention and 24 hours after the run. Results: The 10-km run was enough to decrease triple hop distance and extensor peak torque, and increase levels of creatine kinase (p < 0.05); however, we found no time/group interactions in any of the assessed variables after we applied the appropriate interventions (p > 0.05). Conclusion: 10-min CWI at 10°C was no more effective than water immersion and rest in recovering muscle damage markers after 10-km runs.