Keywords: orthotics, squat, lower limb, kinematics, pronation Introduction Excessive pronation of the foot during exercise has frequently been cited as a risk factor for lower limb injury (Neely, 1998; Buist et al., 2010). The clinical benefits of foot orthotics Vandetanib hypothyroidism in the prevention and alleviation of such injuries have been reported in a variety of populations who exhibit excessive pronation and among a range of lower limb pathologies (Nigg et al., 1999). The underlying causes of these effects are not yet fully understood, since foot orthotics have been found to influence a number of variables. In a recent review, Mills et al. (2009) attempted to broadly categorise the physiological bases for the beneficial effects of foot orthotics in terms of kinematic, shock attenuation and neuromotor control paradigms, while acknowledging that a consensus has yet to be reached on the precise roles and interactions of each of these factors.

In terms of kinematic effects, the lack of uniformity in prescription methods used in the current literature renders comparison of findings between studies difficult (Mundermann et al., 2003). Evidence is also lacking in relation to many specific foot orthotics prescription techniques (Ball and Afheldt, 2002b). Thus it is difficult for clinicians to reach definitive conclusions regarding best practice in foot orthotics prescription. Gross et al. (1991) observed the potential detrimental effect on patient care which this may have, reporting that 13.5% of participants in their study experienced increased severity of symptoms or developed new complaints with custom foot orthotic usage due to poor fitting or diagnosis.

Therefore, research using well-defined prescription methods is required to enable valid comparison of orthotic effects and ensure the best interests of patients are being met. Methods of foot posture and orthotics assessment which incorporate analysis of the dynamic, weight-bearing characteristics of the foot are increasingly being favoured by clinicians due to their functional relevance (Ball and Afheldt, 2002a). This has been achieved in this study through the use of the Neutral Zone Prescription Platform (NZPP) (PPL Biomechanics, Cork, Ireland) to assess and alter alignment of the foot. This novel method utilises a combination of solid platforms with a 10mm shoe pitch, foam arch supports and rearfoot wedges to provide individualised correction of rearfoot alignment to subtalar neutral in weight-bearing (Figure 1).

Once applied, it is recommended that the effectiveness of the prescription is objectively tested using dynamic functional tests, including a bilateral squat (PPL Biomechanics, 2006). The bilateral squat is used particularly to screen Carfilzomib for the occurrence of dynamic knee valgus, the presence of which has been identified as a risk factor for sustaining acute knee injuries during physical activity (Chaudhari and Andriacchi, 2006; Hewett et al., 2005).