The immediate effect of foot orthoses on lower limb neuromotor control in people with patellofemoral joint osteoarthritis: a pilot study Narelle Wyndow1, KM Crossley1, PW Hodges1, H Tsao1, H Ozturk2, HF Hart2, B Vicenzino1, NJ Collins2 1The University of Queensland, Australia; 2The University of Melbourne, Australia The patellofemoral joint (PFJ) is commonly affected by osteoarthritis (OA). Mild PFJ OA causes more significant pain & functional limitations than tibiofemoral joint (TFJ) OA1 . Little is known about the mechanical features, neuromotor patterns and the conservative management of PFJ OA. Study Aims: To determine the immediate effects of foot orthoses on neuromotor patterns of hip, knee and ankle musculature in people with PFJ OA. Background N= 9 (6 females) Age 52 6yrs PFJ osteophytes on x-ray TFJ OA <K & L Grd 3 EMG was recorded from 12 lower limb muscles (GMAX, GMED, RF, TFL, MH, LH, VMO & VL, MG & LG, Sol, TA) while participants walked overground at a self selected pace Heel strike and toe of events were determined from trajectories of vicon heel and toe markers 2 conditions: 1. Footwear 2. Footwear & Orthoses Best 4 trials averaged then analysed EMG onsets & offset determined as a % of stride time (%ST) Paired t-tests (p=0.05) between conditions Methods VAS: baseline pain with walking (mean±SD) 1.3±1.1cm KOOS: pain 68±21, symptoms 69±15, (mean±SD) ADL80±14, sport/rec 62±18, QOL 55±16 Foot orthoses: Delayed ONSET of VL & LH VL: mean difference1.7 % ST [0.01 to 3.4 95% CI], SMD: 0.76 LH: mean difference 8.1%ST [0.05 to 16.3 95%CI], SMD: 0.83 Delayed OFFSET of MG & LG MG: mean difference 2.9 %ST [0.7-3.8 95% CI] , SMD: 1.12 LG: mean difference 2.2%ST [2.6-4.1 95% CI], SMD: 0.87 Results Foot orthoses produce an immediate change in neuromotor control of the lower limb in PFJ OA VL and LH ONSET is delayed with foot orthoses which may reduce lateral patella displacement and thus patellofemoral joint loads2,3 MG and LG OFFSET is delayed with foot orthoses which may be associated with reductions in rearfoot eversion and ankle joint dorsiflexion found in our earlier studies4 Alternatively, these changes may simply be the immediate response of the CNS to a novel perturbation Future studies should include larger sample sizes and longer term follow up to determine the relationship of foot orthoses to pain, function and neuromotor control Conclusions References: 1. Duncan et al (2008) Rheumatology. 47:1704-1707. 2. Cowan et al (2001) Arch Phys Med Rehabil. 82:183-189. 3. Patil et al (2011) The Knee. 18:329-332 4. Collins et al (2012) OA&C. 20:s109