This article is part of the supplement: 3rd Congress of the International Foot and Ankle Biomechanics Community

Open Access Oral presentation

Motion of the rearfoot, ankle and subtalar joints and ankle moments when wearing lateral wedge insoles – results from bone anchored markers

Richard Jones1*, Chris Nester1, Anmin Liu1, Peter Wolf2, Anton Arndt3, Paul Lundgren3 and Arne Lundberg3

Author Affiliations

1 Centre for Health Sciences Research, University of Salford, Salford, Greater Manchester, M6 6PU, UK

2 Sensory Motor Laboratory, ETH Zurich Switzerland

3 Karolinska Hospital , Huddinge, Sweden

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Journal of Foot and Ankle Research 2012, 5(Suppl 1):O10 doi:10.1186/1757-1146-5-S1-O10


The electronic version of this article is the complete one and can be found online at: http://www.jfootankleres.com/content/5/S1/O10


Published:10 April 2012

© 2012 Jones et al; licensee BioMed Central Ltd.

Background

Knee osteoarthritis is a debilitating condition and increased dynamic loading at the knee has been linked with increased progression of the disease. Lateral wedge insoles have been used in clinical practice since the late 1980s. It is theorised that lateral wedge insoles increase the subtalar joint valgus orientation and increase the ankle valgus moment [1], with subsequent reduced knee varus moments [2]. Results have shown that both clinical success and reductions in knee loading vary between people. Differences could be due to person specific foot biomechanics. The aim of this study was to determine the changes in frontal plane foot and ankle motion and moment due to a lateral wedge orthosis.

Materials and methods

Five healthy individuals participated in the study (age, height). An intracortical pin approach to measurement of foot motion was adopted because it enables effects of the orthosis at the individual ankle and subtalar joints to be identified. Accordingly, 1.2 mm intracortical pins were inserted into 9 bones of the foot and leg under local anaesthesia and reflective markers attached to the pins. Individuals walked over a force platform ten times in a control shoe condition and the Salford Lateral Wedge Technology insole™. All data were normalised to stance phase. Orthotic effect was evaluated using motions between tibia-talus, talus-calcaneus, and tibia-calcaneus during the first 50% of stance phase.

Results

Table 1. Raw changes in three segments (-ve change degs = increased eversion) and ankle moment (negative change = increased eversion moment nm/kg) in the 5 individuals compared to control condition.

Conclusions

Although the lateral wedge insole offers a change in the ankle valgus moment, each person’s kinematic response varied (Table 1). This demonstrates that the motions do not occur at one segment as per previous research [1] and therefore other motions in adjacent joints needs to be considered. This is potentially one of the reasons why some people do not respond to the orthosis and suggests that use of biomechanical foot classifications could enable more targeted use of lateral wedge insoles [3].

References

  1. Kakihana W, Akai M, Nakazawa K, Takashima T, Naito K, Torii S: Effects of laterally wedged insoles on knee and subtalar joint moments.

    Arch Phy Med Rehabil 2005, 86(7):1465-1471. Publisher Full Text OpenURL

  2. Jones RK, Chapman GJ, Findlow AH, Parkes M, Forsythe L, Felson DT: Does increased loading occur on the contralateral side in medial knee osteoarthritis and what impact do lateral wedges have on this?

    Osteoarthritis Cartilage 2011, (Suppl 1):S176. OpenURL

  3. Chapman GJ, Jones RK, Findlow AH, Parkes M, Forsythe L, Felson DT: Can we predict responders to lateral wedge insoles in patients with medial knee osteoarthritis.

    Osteoarthritis Cartilage 2011, (Suppl 1):S934. OpenURL