Authors (including presenting author) :
Wang H(1), Ho SH(1)
Affiliation :
Prosthetic and Orthotic Department, Pamela Youde Nethersole Eastern Hospital
Introduction :
The aging population problem is now more serious in Hong Kong. In 2024, 21% of residents are aged 65 or above. More elderlies suffer from knee osteoarthritis. Not only pain, this degenerative disease may also affect patients’ gait. Patients would have decreased step length, stride length and gait speed with an increase in severity of knee OA (Sadbhawna & Sonia, 2014). ‘Stride length’ is the most affected parameter comparing to that of normal people (Shafizadegan et al., 2014). These gait deviations may affect patients’ quality of life as a result.
Objectives :
Apart from common treatments include exercise, medication of pain killer and operation of knee replacement, the foot orthoses had been proposed to be benefits OA knee patients with knee varus deformity. Lateral-wedged insole can significantly reduce the varus torque during walking (Kerrigan et al., 2002). It can significantly reduce peak knee adduction moment (KAM) and knee adduction angular impulse too (Hinman et al., 2012). However, the effect of this orthotic treatment in patients’ gait is still not very clear. This study aims to explore the use of it and to investigate whether it could improve patients’ gait.
Methodology :
OA knee patients with unilateral or bilateral varus deformity were referred from O&T Department. Bilateral 5∘lateral-wedged orthotic insoles with customized arch support were fabricated by CADCAM system and prescribed to patients. Saptio-temporal parameters of their gait were assessed at their normal pace by using triaxial accelerometer before and after 3 months treatment when walking with the orthoses. Data were analyzed to investigate the long-term effect of the lateral-wedged orthotic insole in patients’ gait pattern.
Result & Outcome :
This study investigated the effects of orthotic treatment on 19 patients with varus deformity and osteoarthritis (OA) of the knee. The participants, with a mean age of 69.4 years (standard deviation = 7.17), were treated with customized orthotic insoles for a period of 3 to 4 months. The results showed a significant increase in mean stride length (5.22%) and walking speed (7.69%) when wearing the orthotic insoles, as compared to pre-treatment values (p = 0.025 and p = 0.05, respectively). In contrast, a 2.5% decrease in mean cadence was observed, although this difference was not statistically significant (p = 0.313).
The observed increase in stride length and walking speed can be attributed to the reduction in the knee adduction moment (KAM) achieved through the use of the lateral-wedged orthotic insole. Studies have shown that lateral-wedged insoles can reduce KAM by shifting the center of pressure of the ground force laterally (Roodsari et al., 2017). This reduction in KAM may contribute to a decrease in the impulse of KAM, thereby allowing patients to take longer strides and potentially reducing the progression of medial knee OA (Ulrich et al., 2023).
The findings of this study have significant public health implications, as they suggest that the use of personalized lateral-wedged orthotic insoles can be a beneficial conservative management strategy for patients with OA of the knee. By reducing disability and improving quality of life, this treatment may delay the need for major surgical intervention and provide a more effective alternative for patients with OA of the knee
