Asymmetries are the norm, whether they are anatomic or functional. This however does not mean that there may, or may not, be present or future consequences to the asymmetries. It can take time for compensations to develop to accommodate these compensations, and it may take even further time for the body to present (and perhaps not present) consequences to the compensations.
In this study, progressing osteoarthritis in the hip began to eat away as some functional parameters that might otherwise have allowed for more symmetrical step and strike lengths, and one must not forget step width has to be in this discussion as well.
"The patients walked significantly slower than the controls (p=0.002), revealed significantly reduced joint excursions of the hip (p<0.001) and knee (p=0.011), and a reduced hip flexion moment at midstance and peak hip extension (p<0.001). Differences were primarily manifested during the latter 50% of stance, and were persistent when controlling for velocity." - Eitzen et al.
Thus, to walk a straight line, some adaptive compensations will have to occur in the body to enable a linear progression. This might mean altering hip extension patterns, altering hip rotation relationships within the affected hip and thus of the contralateral hip (which might lead to pelvis distortion patterning), pelvis drift in the frontal plane, pelvis drift in the sagittal plane (APT, PPT), asymmetries in spinal rotation and thus arm swing, to name a few just regionally at the hip-pelvis-spine interval. Adaptations must be made. The question is, does your gait assessment afford you the insight to be addressing the problem, or merely their visible compensation, that is the hard part. And remember what we always say, you gait analysis is only going to show you what your client is doing, not why they are doing it. Thus, fixing what you see is likely not fixing
"Reduced gait velocity, reduced sagittal plane joint excursion, and a reduced hip flexion moment in the late stance phase of gait were found to be evident already in hip osteoarthritis patients with mild to moderate symptoms, not eligible for total hip replacement. " - Eitzen et al.
* Differences were primarily manifested during the latter 50% of stance, and were persistent when controlling for velocity.
BMC Musculoskelet Disord. 2012 Dec 20;13:258. doi: 10.1186/1471-2474-13-258.
Sagittal plane gait characteristics in hip osteoarthritis patients with mild to moderate symptoms compared to healthy controls: a cross-sectional study.
Eitzen I1, Fernandes L, Nordsletten L, Risberg MA.