METHODS: Twenty-three collegiate male soccer players (22.1±1.7 years) were tested in four conditions; vertical jump (VJ), vertical jump immediately after slow running (VJSR), vertical jump immediately after sprinting (VJFR) and double horizontal jump immediately after sprinting (HJFR). The kinematics and kinetics data were measured using Vicon motion analyzer (100Hz) and two Kistler force platforms (1000Hz), respectively.
RESULTS: For knee flexion joint angle, (p = 0.014, η = 0.15) and knee valgus moment (p = 0.001, η = 0.71) differences between condition in the landing phase were found. For knee valgus joint angle, a main effect between legs in the jumping phase was found (p = 0.006, η = 0.31), which suggests bilateral deficit existed between the right and left lower limbs.
CONCLUSION: In brief, the important findings were greater knee valgus moment and less knee flexion joint angle proceeding sprint (HJFR & VJFR) rather than no sprint condition (VJ) present an increased risk for knee injuries. These results seem to suggest that running and sudden subsequent jumping-landing activity experienced during playing soccer may negatively change the knee valgus moment. Thus, sprinting preceding a jump task may increase knee risk factors such as moment and knee flexion joint angle.
METHODS: Thirty-six players were divided into 3 groups; FIFA 11+, HarmoKnee and control (n = 12 per group). These exercises were performed 3 times per week for 2 months (24 sessions). The CSR, DCR and FSR were measured before and after the intervention.
RESULTS: After training, the CSR and DCR of knee muscles in both groups were found to be lower than the published normal values (0.61, 0.72, and 0.78 during 60°.s(-1), 180°.s(-1) and 300°.s(-1), respectively). The CSR (60°.s(-1)) increased by 8% and FSR in the quadriceps of the non-dominant leg by 8% in the 11+. Meanwhile, the DCR in the dominant and non-dominant legs were reduced by 40% and 30% respectively in the 11+. The CSR (60°.s(-1)) in the non-dominant leg showed significant differences between the 11+, HarmoKnee and control groups (p = 0.02). As for the DCR analysis between groups, there were significant differences in the non-dominant leg between both programs with the control group (p = 0.04). For FSR no significant changes were found between groups.
CONCLUSIONS: It can be concluded that the 11+ improved CSR and FSR, but the HarmoKnee program did not demonstrate improvement. We suggest adding more training elements to the HarmoKnee program that aimed to enhance hamstring strength (CSR, DCR and FSR). Professional soccer players have higher predisposition of getting knee injuries because hamstring to quadriceps ratio were found to be lower than the average values. It seems that the 11+ have potentials to improve CSR and FSR as well as prevent knee injuries in soccer players.
HYPOTHESIS: We hypothesized that 8 weeks of MIX will provoke the greatest improvements in falls risk factors, followed by similar improvements after BT and VR, relative to the CON.
STUDY DESIGN: Single-blinded randomized controlled trial NCT02778841 (ClinicalTrials.gov identifier).
LEVEL OF EVIDENCE: Level 2.
METHODS: In total, 64 community-dwelling older men (age 71.8 ± 6.09 years) were randomly assigned into BT, VR, MIX, and CON groups and tested at baseline and at the 8-week follow-up. The training groups exercised for 40 minutes, 3 times per week, for 8 weeks. Isokinetic quadriceps and hamstrings strength on the dominant and nondominant legs were primary outcomes measured by the Biodex Isokinetic Dynamometer. Secondary outcomes included 1-legged stance on firm and foam surfaces, tandem stance, the timed-up-and-go, and gait speed. Separate one-way analyses of covariance between groups were conducted for each outcome using baseline scores as covariates.
RESULTS: (1) MIX elicited greater improvements in strength, balance, and functional mobility relative to BT, VR, and CON; (2) VR exhibited better balance and functional mobility relative to BT and CON; and (3) BT demonstrated better balance and functional mobility relative to CON.
CONCLUSION: The moderate to large effect sizes in strength and large effect sizes for balance and functional mobility underline that MIX is an effective method to improve falls risk among older adults.
CLINICAL RELEVANCE: This study forms the basis for a larger trial powered for falls.