Context: Anterior tibial shear force and knee valgus moment increase anterior cruciate ligament (ACL) loading. Muscle coactivation of the quadriceps and hamstrings influences anterior tibial shear force and knee valgus moment, thus potentially influencing ACL loading and injury risk. Therefore, identifying exercises that facilitate balanced activation of the quadriceps and hamstrings might be beneficial in ACL injury rehabilitation and prevention.
Objective: To quantify and compare quadriceps with hamstrings coactivation electromyographic (EMG) ratios during commonly used closed kinetic chain exercises.
Design: Cross-sectional study.
Setting: Research laboratory.
Patients Or Other Participants: Twenty-seven healthy, physically active volunteers (12 men, 15 women; age = 22.1 ± 3.1 years, height = 171.4 ± 10 cm, mass = 72.4 ± 16.7 kg).
Intervention(s): Participants completed 9 separate closed chain therapeutic exercises in a randomized order.
Main Outcome Measure(s): Surface electromyography quantified the activity level of the vastus medialis (VM), vastus lateralis (VL), medial hamstrings (MH), and biceps femoris (BF) muscles. The quadriceps-to-hamstrings (Q:H) coactivation ratio was computed as the sum of average quadriceps (VM, VL) EMG amplitude divided by the sum of average hamstrings (MH, BF) EMG amplitude for each trial. We used repeated-measures analyses of variance to compare Q:H ratios and individual muscle contributions across exercises (α = .05), then used post hoc Tukey analyses.
Results: We observed a main effect for exercise (F(3,79) = 22.6, P< .001). The post hoc Tukey analyses revealed smaller Q:H ratios during the single-limb dead lift (2.87 ± 1.77) than the single-limb squat (5.52 ± 2.89) exercise. The largest Q:H ratios were observed during the transverse-lunge (7.78 ± 5.51, P< .001), lateral-lunge (9.30 ± 5.53, P< .001), and forward-lunge (9.70 ± 5.90, P< .001) exercises.
Conclusions: The most balanced (smallest) coactivation ratios were observed during the single-limb dead-lift, lateral-hop, transverse-hop, and lateral band-walk exercises. These exercises potentially could facilitate balanced activation in ACL rehabilitation and injury-prevention programs. They also could be used in postinjury rehabilitation programs in a safe and progressive manner.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3396299 | PMC |
http://dx.doi.org/10.4085/1062-6050-47.4.01 | DOI Listing |
Knee Surg Sports Traumatol Arthrosc
January 2025
Perth Orthopaedic & Sports Medicine Research Institute, West Perth, Western Australia, Australia.
Purpose: To investigate kneeling tolerance in patients undergoing hamstring (HT) versus quadriceps (QT) anterior cruciate ligament reconstruction (ACLR) and investigate correlation with patient-reported outcome measures (PROMs).
Methods: After recruitment and randomisation, 112 patients (HT = 55; QT = 57) underwent ACLR. Patients were assessed at 6, 12 and 24 months using the Kneeling Tolerance Test, which evaluates patient-reported pain in a position of both 90 (KT90) and 110 (KT110) degrees of knee flexion.
Int J Exerc Sci
December 2024
John G. Rangos, Sr. School of Health Sciences, Duquesne University, Pittsburgh, Pennsylvania, USA.
The purpose was to summarize the studies examining knee strength in young athletes and provide valuable insights into the magnitude of changes in knee flexion and extension strength during the transition from pre-puberty to puberty among male and female athletes. The literature search was conducted through Cochrane Library, Embase, PubMed, Web of Science. Cohen's effect size (ES) and 95% confidence intervals (CIs) were computed using a random effects model.
View Article and Find Full Text PDFJ Sports Med Phys Fitness
January 2025
Physical Medicine and Rehabilitation Unit, Department of Medical and Surgical Sciences, Magna Graecia University, Catanzaro, Italy.
Introduction: Sports injuries involving bi-articular muscles like the hip flexors, hamstrings, quadriceps, and gastrocnemius significantly affect athletes' performance and quality of life. Comprehensive rehabilitation is crucial for a pain-free return to play (RTP). Over the past 15 years, platelet-rich plasma (PRP) has emerged for its potential in tissue regeneration.
View Article and Find Full Text PDFBr J Sports Med
December 2024
Sahlgrenska Sports Medicine Center, Gothenburg, Sweden.
Objective: To evaluate the association between limb symmetry index (LSI) in quadriceps and hamstrings strength together with hop tests, as a proxy of recovery, and the deviation from being symmetrical (LSI 100%), with a safe return to sport (RTS) after anterior cruciate ligament reconstruction (ACL-R).
Methods: Athletes between 15 and 30 years old with a preinjury Tegner activity level ≥6 were eligible for inclusion. Data were extracted from a rehabilitation-specific registry, Project ACL (Gothenburg, Sweden) at the time of or after RTS for each athlete.
Asia Pac J Sports Med Arthrosc Rehabil Technol
January 2025
Department of Sports Medicine, Huashan Hospital, Fudan University, Shanghai, China.
Background: Persistent maladaptive changes of corticospinal tract (CST) and quadriceps strength deficits exist in patients with anterior cruciate ligament reconstruction (ACLR). This study aimed to investigate the relationships between the structural alterations of CST and quadriceps muscle strength deficits in patients with ACLR.
Methods: Twenty-nine participants who had undergone unilateral ACLR (29 males; age = 32.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!