Ground Contact Time asymmetry is a measure of the difference in GCT between legs. GCT asymmetries are correlated to lower running efficiencies.
GCT asymmetries and previous injury - When comparing well-trained athletes who had had previous injury and those who had not, GCT asymmetries were significantly higher for the previous injury group in high intensity, short duration runs.
Adams, Douglas, Pozzi, Federico, Willy, Richard W, Carrol, Anthony, & Zeni, Joseph. (2018). ALTERING CADENCE OR VERTICAL OSCILLATION DURING RUNNING: EFFECTS ON RUNNING RELATED INJURY FACTORS. International Journal of Sports Physical Therapy, 13(4), 633–642. https://doi.org/10.26603/ijspt20180633
GCT asymmetries and treadmill running - Subjects with diagnosed knee osteoarthritis showed lower GCT asymmetries. Treadmill running led to gait adaptations of the unaffected leg to function more like the affected leg, causing smaller steps and less impact force.
Robadey J, Staudenmann D, Schween R, Gehring D, Gollhofer A, Taube W (2018) Lower between-limb asymmetry during running on treadmill compared to overground in subjects with laterally pronounced knee osteoarthritis. PLoS ONE 13(10): e0205191. https://doi.org/10.1371/journal. pone.0205191