Foot orthoses research: identifying limitations to improve translation to clinical knowledge and practice.

Foot orthoses are employed to treat musculoskeletal injury. Research in this field has increased greatly in the past two decades, with researchers publishing ‘placebo’ and ‘sham’-controlled trials within the foot orthoses literature1 ,2 which appears encouraging. However, there are insufficient predictive models for the myriad of musculoskeletal injuries that are being attempted to be treated, let alone a firm understanding of how the design variables of the foot orthoses employed within such studies are influencing the biomechanics of the injured tissues.Foot orthoses can only exert their therapeutic effects either psychologically (via a placebo effect) and/or by directly modifying reaction forces at the foot–orthosis interface in terms of their magnitudes, location and timing.3 Traditionally, foot orthoses were assumed to exert their primary effects via kinematic change and realigning the skeleton, but this seems unlikely.4 Musculoskeletal injury relates to tissue loading, and clearly, foot orthoses may induce a change in tissue loading without a significant change in foot kinematics.5 Thus, foot …