BECKETT, JAMES R. J.; SCHNEIKER, KNUT T.; WALLMAN, KAREN E.; DAWSON, BRIAN T.; GUELFI, KYM J.

This study examined the effects of static stretching in the recovery periods of field-based team sports on subsequent repeated sprint ability (RSA) and change of direction speed (CODS) performance.

on 4 days, 12 male team-sport players completed a standardised warm-up, followed by a test of either RSA or CODS. Both tests involved three sets of maximal sprint repetitions, with each set containing 6 reps. A 4-min recovery was permitted between sets. During this rest, the participants either rested (control) or completed a static stretching protocol. The RSA test involved straight-line sprints, whereas the CODS test required a change of direction (100°) every 4 m. Mean, total (sum of six sprints), first, and best sprint times were recorded for each set.

Results show there was a tendency for RSA times to be slower after the static stretching intervention. Further, sprint times again tended to be slower in the CODS trial for the stretching group, across all sprint variables, with a significantly slower ‘best sprint time’ in set 3 after static stretching.

These results suggest that static stretching of the legs between efforts may negatively affect RSA performance but has less effect on CODS performance.

Medicine & Science in Sports & Exercise:Volume 41(2)February 2009pp 444-450

Richard B. Souza, Christopher M. Powers

The aim of this study is to determine whether women with patellofemoral pain (PFP) show differences in hip kinematics, hip muscle strength, and hip muscle activation in comparison to pain-free controls.

21 females with PFP and 20 pain-free controls were used in this research. Hip kinematics and activity level of hip musculature were obtained during running, a drop jump, and a step-down maneuver. Isometric hip muscle torque production was quantified using a multimodal dynamometer.

Results showed that females with PFP had a greater peak hip internal rotation compared to the control group. The individuals in the PFP group also exhibited reduced hip torque production compared to the control group. Greater gluteus maximus recruitment was observed for individuals in the PFP group during running and the step-down task.

The study shoes that females in the PFP group had increased hip internal rotation and reduced hip muscle strength. They also activated Gluteus Maximus more than the control individuals, suggesting that they were attempting to recruit a weaker muscle in order to stabilise the hip. Our results support the proposed link between abnormal hip function and PFP.

J Orthop Sports Phys Ther 2009;39(1):12-19

Myer, Gregory D; Ford, Kevin R; Barber Foss, Kim D; Liu, Chunyan; Nick, Todd G; Hewett, Timothy E

The aim of this study was to examine the relationship between quadriceps and hamstrings strength in anterior cruciate ligament (ACL) injury risk in female athletes.

22 female athletes who subsequently suffered confirmed noncontact ACL ruptures were matched (1:4 ratio) to 88 female controls using limb, pubertal status, sport, and nearest height and mass. In addition, 22 male controls were used to serve as a secondary comparative control.

Those who subsequently suffered ACL injuries had decreased hamstring strength compared to the female and male controls. Conversely, the ACL injury groups subjects did not differ compared to the male controls in quadriceps strength, and the female controls demonstrated decreased quadriceps strength relative to the male controls.

This studies results show that female athletes who went on to suffer ACL injury had a combination of lower hamstring strength but equal quadriceps strength compared to males. Interestingly, female controls who did not suffer ACL injuries had lower quadriceps strength and equal hamstrings strength compared to matched male athletes.

Clinical Journal of Sport Medicine:Volume 19(1)January 2009pp 3-8