Crenshaw, Jeremy R.

Gait analysis is useful for revealing pathologic tibial rotation in children with cerebral palsy (CP), thus guiding interventions of de-rotational osteotomy [1]. Surface marker misplacement may cause an inaccurate definition of the knee flexion axis, which generates downstream artifacts such as cross talk between knee rotation angles and internal rotation errors, misleading these patients’ assessments and surgical interventions [2,3]. Therefore, the purpose of this study was to develop and evaluate a novel method for defining the true knee flexion axis from existing marker trajectories during gait. We hypothesized that the devised method would accurately quantify the offset in the flexion axis due to a systematically misplaced marker and correct the downstream crosstalk and rotation errors of the knee joint angles associated with the marker misplacement.

The risk of falling reportedly increases almost 2.5-times in those with lower extremity osteoarthritis (OALE) compared with age-matched controls. However, the mechanisms underlying the increased risk are not clear. The risk factors for falls in people with OALE found in the literature are mostly the same as the risk factors for people without OALE. It is hypothesized that risk factors for falls are exacerbated by OALE, such that these individuals are more likely to become dynamically unstable and, once this has occurred, are less able to perform an appropriate compensatory stepping response compared with people without OALE. To the extent that this is true, task-specific training targeting the compensatory step, which decreases falls in middle-aged and older women, should be effective for people with OALE. The purpose of the present review is to provide the rationale for the above hypothesis. Furthermore, the present authors present evidence that the fall risk of people with OALE could be efficiently and effectively reduced using task-specific training previously shown to reduce falls in middle aged and older women.