The Effects of Cadence Manipulation on Joint Kinetic Patterns and Stride-to-Stride Kinetic Variability in Female Runners.

Altering running cadence is commonly done to reduce the risk of running-related injury/reinjury. This study examined how altering running cadence affects joint kinetic patterns and stride-to-stride kinetic variability in uninjured female runners. Twenty-four uninjured female recreational runners ran on an instrumented treadmill with their typical running cadence and with a running cadence that was 7.5% higher and 7.5% lower than typical. Ground reaction force and kinematic data were recorded during each condition, and principal component analysis was used to capture the primary sources of variability from the sagittal plane hip, knee, and ankle moment time series. Runners exhibited a reduction in the magnitude of their knee extension moments when they increased their cadence and an increase in their knee extension moments when they lowered their cadence compared with when they ran with their typical cadence. They also exhibited greater stride-to-stride variability in the magnitude of their hip flexion moments and knee extension moments when they deviated from their typical running cadence (ie, running with either a higher or lower cadence). These differences suggest that runners could alter their cadence throughout a run in an attempt to limit overly repetitive localized tissue stresses.

Female Athletes Exhibit Greater Trial-to-Trial Coordination Variability When Provided with Instructions Promoting an External Focus.

The purpose of this study was to examine how instructions promoting different attentional foci influence joint coordination patterns and trial-to-trial coordination variability during landing. Sixteen females performed drop landings with their typical technique (baseline) and after receiving instructions promoting an internal focus and an external focus. The coordination patterns, and trial-to-trial coordination variability, of the sagittal plane hip-knee, hip-ankle, and knee-ankle angle pairings were compared across conditions. While there was no difference in the joint coordination patterns among the conditions, subjects exhibited greater hip-ankle and knee-ankle trial-to-trial coordination variability for the external focus condition, vs. the baseline and internal focus conditions, which may help to explain the improved motor learning outcomes for athletes who train with an external focus.

A comparison of whole body vibration and moist heat on lower extremity skin temperature and skin blood flow in healthy older individuals.

BACKGROUND: Tissue healing is an intricate process that is regulated by circulation. Heat modalities have been shown to improve skin circulation. Recent research supports that passive vibration increases circulation without risk of burns. Study purpose is to compare and determine effects of short duration vibration, moist heat, and a combination of the two on skin blood flow (SBF) and skin temperature (ST) in elderly, non-diabetic individuals following short-term exposure. MATERIAL/METHODS: Ten subjects, 3 female and 7 male (55-73 years of age), received two interventions over three days: 1--Active vibration, 2--passive vibration, 3--moist heat, 4--moist heat combined with passive vibration (MHPV), 5--a commercial massaging heating pad, and 6--no intervention. SBF and ST were measured using a MOOR Laser Doppler before and after the intervention and the third measurement were taken 10 minutes following. RESULTS: Mean SBF following a ten-minute intervention were significantly different in the combination of moist heat and passive vibration from the control, active vibration, and the commercial massaging heating pad. Compared to baseline measurements, this resulted in mean SBF elevation to 450% (at conclusion of 10 minutes of intervention) and 379% (10 minutes post). MHPV (p=0.02) showed significant changes in ST from the commercial massaging heating pad, passive vibration, and active vibration interventions. CONCLUSIONS: SBF in the lower legs showed greatest increase with MHPV. Interventions should be selected that are low risk while increasing lower extremity skin blood flow.