Men's shoes and knee joint torques relevant to the development and progression of knee osteoarthritis.

OBJECTIVE: To determine if men's dress shoes and sneakers increase knee joint torques and play the same role in the development and/or progression of knee osteoarthritis (OA) as women's high-heeled dress shoes. METHODS: Three-dimensional data regarding lower extremity torques and motion were collected during walking in 22 healthy men while (1) wearing dress shoes, (2) wearing sneakers, and (3) barefoot. Data were plotted and qualitatively compared; major peak values were statistically compared between conditions. RESULTS: The external knee varus torque in early stance was slightly greater with the dress shoes and sneakers, but this slight increase can be explained by the faster walking speed with shoes. No significant increases were found in any other of the sagittal, coronal, or transverse knee torques when walking with dress shoes and sneakers compared to barefoot. CONCLUSION: Men's dress shoes and sneakers do not significantly affect knee joint torques that may have relevance to the development and/or progression of knee OA.

Predicting peak kinematic and kinetic parameters from gait speed.

OBJECTIVE: The aim of this study is to assess the predictability of the relationships between gait speed and common peak sagittal plane parameters in order to provide a set of reference parameter values. DESIGN: Lower extremity biomechanical data were collected in 64 healthy adults while walking barefoot at his/her comfortable walking speed, then at self-selected fast, slow and very slow speeds. Twenty seven peak joint parameter values were plotted and regressed as a function of gait speed. DISCUSSION: While most parameters change with increasing gait speed, in general, the kinetic parameters had better predictability than the kinematic parameters. Most of the power parameters were found to have a quadratic relationship with gait speed. Of the moment parameters, four had a linear relationship with gait speed, while four had a quadratic one. These relationships shown in the tables and graphs here can be used as a reference for 'normal' gait parameter values.

Gender differences in pelvic motions and center of mass displacement during walking: stereotypes quantified.

OBJECTIVES: A general perception that women and men walk differently has yet to be supported by quantitative walking (gait) studies, which have found more similarities than differences. Never previously examined, however, are pelvic and center of mass (COM) motions. We hypothesize the presence of gender differences in both pelvic obliquity (motion of the pelvis in the coronal plane) and vertical COM displacement. Quantifiable differences may have clinical as well as biomechanical importance. METHODS: We tested 120 subjects separated into four groups by age and gender. Pelvic motions and COM displacements were recorded using a 3-D motion analysis system and averaged over three walking trials at comfortable walking speed. Data were plotted, and temporal values, pelvic angle ranges, and COM displacements normalized for leg length were quantitatively compared among groups. RESULTS: Comparing all women to all men, women exhibited significantly more pelvic obliquity range (mean ISD): 9.4 +/- 3.5 degrees for women and 7.4 +/- 3.4 degrees for men (p = 0.0024), and less vertical COM displacement: 3.7 +/- 0.8% of leg length for women and 3.3 +/- 0.9% for men (p = 0.0056). CONCLUSIONS: Stereotypically based gender differences were documented with greater pelvic obliquity and less vertical COM displacement in women compared with men. It is unclear if these differences are the intrinsic result of gender vs. social or cultural effects. It is possible that women use greater pelvic motion in the coronal plane to reduce their vertical COM displacement and, thus, conserve energy during walking. An increase in pelvic obliquity motion may be advantageous from an energy standpoint, but it is also associated with increased lumbosacral motion, which may be maladaptive with respect to the etiology and progression of low back pain.

Effectiveness of a lateral-wedge insole on knee varus torque in patients with knee osteoarthritis.

OBJECTIVES: To test whether a lateral-wedged insole, inclined at 5 degrees or 10 degrees, significantly reduces knee varus torque during walking in patients with knee osteoarthritis compared with both using no insole and with wearing nonwedged control insoles of the same material and average thickness. DESIGN: Patients with medial knee osteoarthritis were studied while they walked wearing their comfortable shoes (1) without an insole; (2) with a 5 degrees lateral wedge compared with a nonwedged, 3.175-mm (1/8-in) even-thickness control insole; and (3) with a 10 degrees lateral wedge compared with a nonwedged 6.35-mm ((1/4)-in) even-thickness control insole. SETTING: A gait laboratory with 3-dimensional motion analysis and force platform equipment. PARTICIPANTS: Fifteen patients with clinical and radiographic osteoarthritis of the medial compartment of 1 knee. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Peak external knee varus torques during the stance period of gait. Data regarding lower-extremity joint torques and motions were collected, and knee joint torques using the different insoles and wedges were compared by analysis of variance. RESULTS: Although responses varied among individuals, as a group, both the 5 degrees and 10 degrees lateral-wedge insoles significantly reduced the knee varus torque during walking compared with walking with no insole and walking with nonwedged 3.175-mm and 6.35-mm control insoles. Compared with no insole, the 5 degrees wedge reduced the peak knee varus torque values by about 6% and the 10 degrees wedge reduced the peaks by about 8%. Although there were no significant differences in speed of walking between the conditions, the 10 degrees wedge and 6.35-mm control insoles were associated with varying degrees of discomfort. CONCLUSION: Both wedge insoles are effective in reducing the varus torque during walking beyond what theoretically could be explained by a reduced walking speed or cushioning effect from the insole. These data imply that wedged insoles are biomechanically effective and should reduce loading of the medial compartment in persons with medial knee osteoarthritis. Although the effect of the 5 degrees wedge was smaller, it may be more comfortable than the 10 degrees wedge to wear inside one's own shoes.