1. 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 % CI], SMD: 0.76 LH: mean difference 8.1%ST [0.05 to %CI], SMD: Delayed OFFSET of MG & LG MG: mean difference 2.9 %ST [ % CI] , SMD: 1.12
LG: mean difference 2.2%ST [ % 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: Cowan et al (2001) Arch Phys Med Rehabil. 82: Patil et al (2011) The Knee. 18: Collins et al (2012) OA&C. 20:s109