Electromyography Evaluation of Bodyweight Exercise Progression in a Validated Anterior Cruciate Ligament Injury Rehabilitation Program: A Cross-Sectional Study

Surface Electromyography and Gait Features in Patients after Anterior Cruciate Ligament Reconstruction

OBJECTIVE

An important reason for the poor recovery of anterior cruciate ligament (ACL) injuries is the poor recovery of muscle function. Therefore, we used surface electromyography (sEMG) and gait analysis to explore the muscle activation patterns and gait characteristics between lower limbs under different exercise states in patients, following anterior cruciate ligament reconstruction (ACLR).

METHODS

Forty-one adults with unilateral ACL injuries in Binzhou Medical University Hospital from October 2022 to June 2023 were allocated to three groups according to the time after ACL reconstruction: group A (≤3 months, 16), group B (3 months-1 year, 13), and group C (>1 year, 12). Patients were tested by sEMG and gait, while straight leg raising (SLR), walking at normal speed, fast walking, and walking up and down the stairs. Two related sample tests were performed for the normalized root mean square (RMS) values and gait parameters.

RESULTS

Muscle function changes varied in different training tasks. The RMS value of the involved side was more than the uninvolved side in biceps femoris and semitendinosus of group A (p < 0.010), and for the bilateral rectus femoris (RS), vastus medialis (VM), and vastus lateralis in group B, only the comparison of the RS was significant in group C during fast walking and going up and down the stairs. The ground impact (0.90 [0.63, 1.33] vs. 0.71 [0.43, 1.02], p = 0.035) of the uninvolved side was significantly decreased compared to those of the involved side in patients with ACLR when going down the stairs.

CONCLUSION

Different muscles need to be focused on at different stages of the postoperative period. sEMG and gait analysis can guide the development of a rehabilitation program.

Quadriceps Architectural Adaptations in Team Sports Players: A Meta-analysis

Resistance training is the most effective strategy to modify muscle architecture, enhancing sport performance and reducing injury risk. The aim of this study was to compare the effects of high loads (HL) versus lower loads (LL), maximal versus submaximal efforts, and high frequency (HF) versus low frequency (LF) on quadriceps architectural adaptations in team sports players. Five databases were searched. Vastus lateralis thickness, fascicle length and pennation angle, and rectus femoris thickness were analyzed as main outcomes. Overall, resistance training significantly improved muscle thickness and pennation angle, but not fascicle length. LL led to greater fascicle length adaptations in the vastus lateralis compared to HL (p=0.01), while no substantial differences were found for other load comparisons. Degree of effort and training frequency did not show meaningful differences (p>0.05). In conclusion, LL lengthen the fascicle to a greater extent than HL, and training with LL twice a week could maximize architectural adaptations, whereas the degree of effort does not appear to be a determinant variable on quadriceps architectural adaptations.

Comparison of muscle activation during quadrupedal movement training and traditional bodyweight exercises

Quadrupedal movement training (QMT) is a unique form of bodyweight training shown to improve flexibility, FMS scores, and proprioception, however, little is known about its muscle activation characteristics. Therefore, the purpose of this study was to compare surface EMG (sEMG) activity of muscles of the trunk, upper, and lower extremity during QMT movements and common traditional bodyweight exercises (TRA). Twenty (males n = 9) participants (age: 27.5 ± 10.8 yrs, height: 169.0 ± 7.0 cm, mass: 66.6 ± 10.9 kg) were prepped and fitted with sEMG electrodes on their right-side bicep brachii, medial deltoid, triceps brachii, pectoralis major, latissimus dorsi, rectus abdominus, rectus femoris and bicep femoris. Following completion of maximal voluntary isometric contraction (MVIC) tests for normalization, participants performed 4 repetitions of 8 QMT exercises (from the Animal Flow™ system) and 3 TRA exercises (pushup, squat and forearm plank) in random order. The pooled peak muscle activations of all QMT exercises resulted in moderate (21-40% MVIC) to very high (>60% MVIC) peak muscle activation levels for each muscle group with significantly higher (p > 0.05) muscle activation for the biceps (47.72 ± 21.41%), deltoid (66.58 ± 11.39%), and latissimus dorsi (62.81 ± 18.14%) than the pushup (23.31 ± 16.95, 45.63 ± 18.59, 29.17 ± 20.58% respectively) and significantly higher activation of the bicep femoris (41.89 ± 13.83%) than the squat (17.79 ± 11.12%). TRA (pushup) showed significantly higher activation of the triceps and pectoralis. There were no differences in rectus femoris or rectus abdominus. Muscle activation levels during QMT are comparable to or higher than common traditional bodyweight exercises and therefore may be an appealing strategy for training multiple muscle groups simultaneously.

Surface electromyography characteristics of patients with anterior cruciate ligament injury in different rehabilitation phases

Background: Anterior cruciate ligament reconstruction (ACLR) is a common treatment for anterior cruciate ligament (ACL) injury. However, after ACLR, a significant proportion of patients do not return to pre-injury levels. Research on muscle function during movement has important implications in rehabilitation. Methods: Sixty patients with unilateral ACL injury were recruited for this study and assigned into three groups: group A, individuals with an ACL injury before 6 months; group B, individuals with ACLR from 6 months to 1 year; and group C, individuals with ACLR 1 year later. Surface electromyography (SEMG) signals were collected from the bilateral rectus femoris (RF), vastus medialis (VM), vastus lateralis (VL), biceps femoris (BF), and semitendinosus (ST). The tasks performed during the experiment included straight leg raising (SLR) training at 30°, SLR training at 60°, ankle dorsiflexion, walking, and fast walking. Results: In the maximum muscle strength test, the affected side of the BF in group A (199.4 ± 177.12) was significantly larger than in group B (53.91 ± 36.61, p = 0.02) and group C (75.08 ± 59.7, p = 0.023). In the walking test, the contralateral side of the RF in group B (347.53 ± 518.88) was significantly greater than that in group C (139.28 ± 173.78, p = 0.029). In the SLR training (60°) test, the contralateral side of the RF in group C (165.37 ± 183.06) was significantly larger than that in group A (115.09 ± 62.47, p = 0.023) and smaller than that in group B (226.21 ± 237.17, p = 0.046); In the ankle dorsiflexion training test, the contralateral side of the RF in group B (80.37 ± 87.9) was significantly larger than that in group C (45.61 ± 37.93, p = 0.046). Conclusion: This study showed the EMG characteristics of patients with ACL injury helped to determine which muscle requires more training and which exercise model would be best suited for intervention.

Reporte de caso de postcirugía de ligamento cruzado anterior

El ligamento cruzado anterior (LCA) es la lesión de la rodilla con mayor prevalencia en los atletas. Los avances en la técnica quirúrgica y la fijación de injertos han permitido a los pacientes participar en una rehabilitación funcional postoperatoria temprana. Este tratamiento está dirigido a lograr un mayor rango de movimiento, progresando hacia la movilización, fortalecimiento y control neuromuscular propioceptivo de la articulación. Existen varios protocolos de rehabilitación con variaciones en ejercicios específicos, progresión a través de fases y componentes claves que permiten la recuperación funcional. El objetivo final de la fisioterapia es devolver al paciente al nivel de rendimiento anterior a la lesión, incluidos el movimiento y la fuerza, sin dañar ni alargar el injerto. Presentamos el reporte de un caso con una lesión de LCA compleja, que recupero la funcionalidad de la articulación por aplicación de plan de tratamiento fisioterapéutico de forma inmediata a su intervención quirúrgica.

Graft Failure, Revision ACLR, and Reoperation Rates After ACLR With Quadriceps Tendon Versus Hamstring Tendon Autografts: A Registry Study With Review of 475 Patients

BACKGROUND

It has been indicated that anterior cruciate ligament reconstruction (ACLR) with a quadriceps tendon (QT) graft has a higher risk of revision compared with ACLR performed with a hamstring tendon (HT) graft.

PURPOSE/HYPOTHESIS

To investigate whether ACLR with QT graft had a higher risk of graft failure, revision ACLR, or reoperation compared with HT graft in a high-volume center. We hypothesized that there would be no between-group differences.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

This was a registry study with review of medical records. Our study cohort consisted of patients who underwent primary ACLR with either QT or HT graft performed at Copenhagen University Hospital Hvidovre between January 2015 and December 2018. The cohort was identified from the Danish Knee Ligament Reconstruction Registry and linked to the Danish National Patient Registry to identify all hospital contacts after ACLR. The outcome variables were graft failure (rerupture or >3-mm side-to-side difference in anteroposterior [AP] laxity), revision ACLR, reoperation due to cyclops lesion, reoperation due to meniscal injury, and reoperation due to any reason. AP laxity and pivot shift were assessed at 1 year. Kaplan-Meier estimates were used to evaluate the rates of events at 2 years, and comparison was performed with Cox regression analysis.

RESULTS

A total of 475 patients (252 HT, 223 QT) were included. The rate of graft failure at 2 years was 9.4% for the QT group and 11.1% for the HT group (P = .46). For the QT and HT groups, respectively, the rate of revision ACLR was 2.3% and 1.6% (P = .60), the rate of reoperation due to cyclops lesion was 5.0% and 2.4% (P = .13), and the rate of reoperation due to meniscal injury was 4.3% and 7.1% (P = .16). The rate of reoperation due to any reason was 20.5% and 23.6% (P = .37). At 1-year follow-up, AP laxity was 1.4 mm for QT and 1.5 mm for HT (P = .51), and the proportion of patients with a positive pivot shift was 29-30% for both groups.

CONCLUSION

QT and HT grafts yielded similar rates of graft failure, revision ACLR, and reoperation at 2 years of follow-up after ACLR. Graft failure was found in 9% to 11% of patients. Patients with QT ACLR showed a non-statistically significant trend of higher risk for reoperation due to cyclops lesion, and those with HT showed a non-statistically significant trend of higher risk for reoperation due to meniscal injury.