Laterally wedged insoles in knee osteoarthritis: Do biomechanical effects decline after one month of wear?

Centre for Health, Exercise and Sports Medicine, School of Physiotherapy, The University of Melbourne, Victoria, Australia.
BMC Musculoskeletal Disorders (Impact Factor: 1.72). 11/2009; 10(1):146. DOI: 10.1186/1471-2474-10-146
Source: PubMed


This study aimed to determine whether the effect of laterally wedged insoles on the adduction moment in knee osteoarthritis (OA) declined after one month of wear, and whether higher reported use of insoles was associated with a reduced effect on the adduction moment at one month.
Twenty people with medial compartment OA underwent gait analysis in their own shoes wearing i) no insoles and; ii) insoles wedged laterally 5 degrees in random order. Testing occurred at baseline and after one month of use of the insoles. Participants recorded daily use of insoles in a log-book. Outcomes were the first and second peak external knee adduction moment and the adduction angular impulse, compared across conditions and time with repeated measures general linear models. Correlations were obtained between total insole use and change in gait parameters with used insoles at one month, and change scores were compared between high and low users of insoles using general linear models.
There was a significant main effect for condition, whereby insoles significantly reduced the adduction moment (all p < 0.001). However there was no significant main effect for time, nor was an interaction effect evident. No significant associations were observed between total insole use and change in gait parameters with used insoles at one month, nor was there a difference in effectiveness of insoles between high and low users of the insoles at this time.
Effects of laterally wedged insoles on the adduction moment do not appear to decline after one month of continuous use, suggesting that significant wedge degradation does not occur over the short-term.

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Available from: Kim Bennell
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    • "KAM impulse has been associated with greater medial tibial cartilage loss over 12 months in patients with medial knee OA and appears to distinguish disease severity better than peak KAM (Benell et al., 2011; Kean et al., 2012). To this end, Hinman et al. (2009, 2012) conducted orthotic studies using 5° lateral wedges on individuals with medial OA, and found that KAM impulse was significantly decreased (5.2% & 6.3% "
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    ABSTRACT: Background Lateral foot wedges represent a biomechanical intervention aimed at reducing medial knee loads. However, the effects of varying wedge amounts on biomechanical variables and orthotic comfort have not been systematically studied. Further, arch height may influence the comfort of laterally wedged devices. Therefore, the primary purpose of this study was to examine the effect of incrementally increasing lateral wedge amounts on knee adduction moment parameters and subjective comfort. The secondary purpose was to relate arch height measures to the comfort of the devices. Methods Twenty-five healthy subjects underwent three-dimensional instrumented gait analysis testing using seven inclinations of lateral wedging (0°, 2°, 4°, 6°, 8°, 10°, 12°). Subjects reported comfort level for each orthotic condition. Arch heights were measured in standing and sitting, and rigidity index and stiffness were calculated. Findings The knee adduction moment decreased with wedge amounts up to 6°, but more aggressive amounts did not yield additional reductions. Comfort ratings did not change from baseline until wedge amounts exceeded 8°. In addition, arch height measures, arch rigidity index and stiffness did not relate to the comfort of the orthotic device regardless of the wedge amount. Interpretation Knee adduction moment decreased with mild wedge amounts while maintaining comfort. Wedge amounts greater than 6° yielded little additional mechanical benefit and amounts greater than 8° compromised comfort. It appears that 4°–6° of lateral wedging are optimal in regard to desirable biomechanical change and comfort level in healthy individuals.
    Full-text · Article · Sep 2014 · Clinical Biomechanics
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    • "Lateral wedged insoles are designed to reduce the external knee adduction moment by altering the path of the centre of pressure laterally with respect to the defined knee centre or origin (Yasuda & Sasaki, 1987) and thus altering loading at the knee. Various authors have investigated knee loading and demonstrated a reduction in the external knee adduction moment in healthy subjects (Kakihana, Akai, & Yamasaki, 2004; Kakihana et al., 2005; Kerrigan et al., 2002), and in individuals with medial tibiofemoral osteoarthritis (Kakihana, Akai, Nakazawa, Naito, & Torii, 2007; Butler, Marchesi, Royer, & Davis, 2007; Hinman, Payne, Metcalf, Wrigley, & Bennell, 2008; Hinman, Bowles, & Bennell, 2009). However, even though the lateral wedged insole has been reported as a very effective and viable solution to reduce the external knee adduction moment during walking, some patients have complained of decreased comfort and even stopped wearing them due to pain in the ankle/subtalar joint complex and other joints (Bennell et al., 2011; Kakihana, Akai, & Yamasaki, 2004). "
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    ABSTRACT: Lateral wedged insoles are a common treatment in individuals with medial tibiofemoral osteoarthritis of the knee joint. One concern has been the potential for increased foot and ankle pain due to increased eversion. The purpose of this study was to assess the biomechanical effectiveness of a typical lateral wedged insole and a combined insole with a lateral wedge and off-the-shelf anti-pronatory device in shoes while walking. A cross-over randomized design was used where each insole was worn by fifteen healthy subjects while three-dimensional motion data were collected in three different conditions: (1) control condition (with standard shoes), (2) with an insole with a lateral wedge and additional off-the-shelf anti-pronatory support (supporting), and (3) with an insole with a lateral wedge with no additional support (unsupported) in the standard shoes. The unsupported insole significantly increased the amount of ankle/subtalar joint complex eversion than the other experimental conditions, with the supporting insole reducing the ankle/subtalar joint complex eversion, and was found to be more comfortable. Both the supporting and unsupported lateral wedged insoles significantly reduced knee loading (external knee adduction moment reduction 8.5% and 9.1%, respectively), the knee adduction angular impulse. This new design of lateral wedge may offer increased adherence in future osteoarthritis population studies while offering reductions in joint loading.
    Full-text · Article · Aug 2013 · Human movement science
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    • "Toda et al., (2005) conducted a study where participants had to wear insoles with subtalar strappings for varying durations over two weeks, and found that the greatest improvement was seen in patients who wore the insoles for eight hours a day [10]. These results were not confirmed by Hinman et al., (2009) who investigated the biomechanical effects of lateral wedges after one month in 20 patients [11]. They found that, irrespective of the duration of daily use, the insoles demonstrated a reduction in adduction moment parameters at one month. "
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    ABSTRACT: Lateral wedges were originally proposed to manage medial compartment osteoarthritis of the knee but recent reviews suggest that lateral wedges do not affect disease progression. We performed a systematic review to analyse the recent literature and define how effective, if at all, lateral wedges are in the management of medial compartment osteoarthritis of the knee. The inclusion criteria were defined as any study published within the last decade, using a sample size of at least twenty patients, and investigating the effect of insoles or wedges on either unilateral or bilateral knee varus osteoarthritis. The standardised keyword term 'lateral*wedge*OR insole*OR orthotic* OR medial compartment OR varus OR osteoarthri* OR knee*' was used. We identified 10 studies that fitted our inclusion criteria. Although there is not enough evidence in the literature to prove that lateral wedge orthotics are an effective treatment for varus osteoarthritis of the knee, there is some evidence to suggest that they do have some symptomatic effect. Patients with early osteoarthritis and higher BMI may benefit to a greater extent than those with a greater extent of degenerative changes and lower BMI. The literature is unclear as to what the optimal duration for the use of lateral wedges is, but does support the prolonged use of the wedges as the benefits at one month are maintained at one year. Future studies should be randomised controlled trials with a large sample size with long follow-up, and use objective clinical, biomechanical and radiological outcome measures.
    Full-text · Article · Nov 2012 · The Open Orthopaedics Journal
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