Joint loading decreased by inexpensive and minimalist footwear in elderly women with knee osteoarthritis during stair descent.

OBJECTIVE: Previous studies indicate that flexible footwear, which mimics the biomechanics of walking barefoot, results in decreased knee loads in patients with knee osteoarthritis (OA) during walking. However, the effect of flexible footwear on other activities of daily living, such as descending stairs, remains unclear. Our objective was to evaluate the influence of inexpensive and minimalist footwear (Moleca) on knee adduction moment (KAM) during stair descent of elderly women with and without knee OA. METHODS: Thirty-four elderly women were equally divided into an OA group and a control group (CG). Stair descent was evaluated in barefoot condition, while wearing the Moleca, and while wearing heeled shoes. Kinematics and ground reaction forces were measured to calculate KAM by using inverse dynamics. RESULTS: The OA group experienced a higher KAM during midstance under the barefoot condition (233.3%; P = 0.028), the Moleca (379.2%; P = 0.004), and heeled shoes (217.6%; P = 0.007). The OA group had a similar knee load during early, mid, and late stance with the Moleca compared with the barefoot condition. Heeled shoes increased the knee loads during the early-stance (versus barefoot [16.7%; P < 0.001] and versus the Moleca [15.5%; P < 0.001]), midstance (versus barefoot [8.6%; P = 0.014] and versus the Moleca [9.5%; P = 0.010]), and late-stance phase (versus barefoot [10.6%; P = 0.003] and versus the Moleca [9.2%; P < 0.001]). In the CG, the Moleca produced a knee load similar to the barefoot condition only during the early-stance phase. CONCLUSION: Besides the general foot protection, the inexpensive and minimalist footwear contributes to decreasing knee loads in elderly women with OA during stair descent. The loads are similar to the barefoot condition and effectively decreased when compared with heeled shoes.

Inter- and intra-tester reliability of clinical measurement to determine medio-lateral patellar position using a pachymeter or visual assessment.

The aim was to investigate inter-tester and intra-tester reliability and parallel reliability between a visual assessment method and a method using a pachymeter for locating the mid-point of the patella in determining the medial/lateral patella orientation. Fifteen asymptomatic subjects were assessed and the mid-point of the patella was determined by both methods on two separate occasions two weeks apart. Inter-tester reliability was obtained by ANOVA and by intraclass correlation coefficient (ICC); intra-tester reliability was obtained by a paired t-test and ICC; and parallel reliability was obtained by Pearson's Correlation and ICC, for the measurement on the first and second evaluations. There was acceptable inter-tester agreement (p=0.490) and reliability for the visual inspection (ICC=0.747) and for the pachymeter (ICC=0.716) at the second evaluation. The inter-tester reliability in the first evaluation was unacceptable (visual ICC=0.604; pachymeter ICC=0.612). Although there was statistical similarity between measurements for the first and second evaluations for all testers, intra-tester reliability was not acceptable for both methods: visual (examiner 1 ICC=0.175; examiner 2 ICC=0.189; examiner 3 ICC=0.155) and pachymeter (examiner 1 ICC=0.214; examiner 2 ICC=0.246; examiner 3 ICC=0.069). Parallel reliability gave a perfect correlation at the first evaluation (r=0.828; p<0.001) and at the second (r=0.756; p<0.001) and reliability was between acceptable and very good (ICC=[0.748-0.813]). Both visual and pachymeter methods provide reliable and similar medial/lateral patella orientation and are reliable between different examiners, but the results between the two assessments at 2 weeks' interval demonstrated an unacceptable reliability.