Selected Kinematic Variables and Oxygen Consumption in Female Runners Who Excessively Pronate

As recreational running increases in popularity, there is also an associated increase in injuries secondary to the biomechanical foot fault of excessive pronation which is defined as either a maximum degree of pronation greater than 13.0 degrees and/or pronation occurring beyond the first 25 percent of stance.1-3 Many studies have indicated a positive correlation between excessive pronation and various injuries such as joint subluxation, overuse injuries, chondromalacia patella, shin splints, stress fractures, sacroiliac dysfunction and Achilles tendon injuries.2-8 The purpose of this study was to research: 1) the relationship between . selected kinematic and metabolic variables and 2) kinematic changes over time between neutral and rearfoot control running shoes during a 30 minute run. Nine female recreational runners classified as symptom free excessive pronators served as subjects. Through motion analysis and V02 uptake, data was compared while subjects ran in two shoe conditions . a neutral and a rearfoot control running shoe. Results yielded from 2-factor repeated measures analysis of variance (ANOV A) tests indicated that the maximal angle of pronation was found to be statistically significant between the two shoe conditions (p=O.O 17) .. Time to maximal angle of pronation (p=0.002) and percentage of stance to maximal angle of pronation (p=0.004) exhibited significant decreases with repeated measures in both shoe conditions. No significant difference was noted in either variable between the shoe conditions. V02 was significantly decreased with repeated measures (p=0.002), but showed no significant difference between the shoe conditions. The implications of these results suggest that while the rearfoot control shoe is effective in limiting the maximal angle of pronation in this population, metabolic efficiency does not improve over the duration of a 30 minute submaximal run. This study further suggests that the rearfoot control shoe may reduce the risk of injury by decreasing the maximal angle of pronation to within normal limits