Kinetic asymmetry in female runners with and without retrospective tibial stress fractures

A Comparison of Negative Joint Work and Vertical Ground Reaction Force Loading Rates in Chi Runners and Rearfoot-Striking Runners

“…Greater braking forces may be problematic, as Milner et al 36 observed greater braking forces in a sample of runners with a history of tibial stress fracture compared to matched controls. Furthermore, Zifchock et al 49 observed greater braking forces in the previously injured limb of females with a history of tibial stress fracture when compared to their uninjured side. The greater braking forces observed in the RS runners also might have contributed to the increased KENW performed in this group.…”

“…AVLRs greater than 70 BW/s have been associated with tibial and metatarsal stress fractures. 48,49 In addition, instantaneous vertical ground reaction force loading rates greater than 100 BW/s have been associated with plantar fasciitis, 40 and AVLRs of 72 BW/s have been linked to patellofemoral pain syndrome. 10,11 Previous authors have observed AVLRs ranging between 60 and 70 BW/s in healthy runners.…”

Differences in plantarflexor function during a stretch-shortening cycle task due to limb preference

“…Asymmetry in lower limb function may be due to a variety of factors including lateralisation (Gabbard & Hart, 1996), sport and training background (Cavanagh, Pollock, & Landa, 1977;Cromie, Greenwood, & McCullagh, 2007), injury (Schiltz et al, 2009;Zifchock, Davis, & Hamill, 2006), speed of movement (Cavagna, 2006;Schiltz et al, 2009), age (Atkins, Hesketh, & Sinclair, 2013), muscle activation (Valderrano et al, 2007) or contextual interference (Vagenas & Hoshizaki, 1992).…”

The symmetry angle: A novel, robust method of quantifying asymmetry

“…Such measures have been used in the past to characterize normal levels of asymmetry in healthy individuals [1,2]. Additionally, since asymmetry is often associated with pathology, comparisons of symmetry levels have been drawn between groups [3] and in the same group prior to and following an intervention [4].…”

“…Assessing asymmetry in a healthy population can be difficult where there is no obvious side to use as a reference; thus, the average of the two sides is often used. Zifchock et al [3] compared asymmetry levels between subjects with a history of tibial stress fracture and healthy controls. These authors calculated the SI values of both groups using the average of their left and right sides as the reference value.…”