Kinematic predictors of loading during running differ by demographic group

Objectives
To investigate whether previously-determined kinematic predictors of kinetics during running differ between demographic groups.

Participants
Young male (n = 13, age = 22 (2) yrs), young female (n = 13, age = 25 (4) yrs), older male (n = 13, age = 50 (4) yrs) and older female (n = 13, age = 52 (3) yrs) runners.

Main outcome measures
Sagittal plane kinematics and kinetics were assessed while participants ran at their preferred pace. Linear regression models were developed to predict kinetics in each group using kinematics as independent variables.

Results
Step length was positively associated with magnitude of at least one kinetic variable in all groups. Step position was inversely associated with vertical ground reaction force variables in all groups. Step frequency and CoM excursion were also important to all groups, however direction of the associations varied. Foot angle at initial contact was important to all groups except older females. Peak knee flexion was most important to older females, but was not important to any other groups.

Conclusion
Optimal parameters for gait analysis of runners may depend on demographics of the individual. This provides insight for clinicians into the most effective evaluation and interventions strategies for different types of runners.