@article{25701, author = {Soysa A and Hiller C and Refshauge K and Burns J}, title = {Importance and challenges of measuring intrinsic foot muscle strength}, abstract = {
Background: Intrinsic foot muscle weakness has been implicated in a range of foot deformities and disorders.
However, to establish a relationship between intrinsic muscle weakness and foot pathology, an objective measure
of intrinsic muscle strength is needed. The aim of this review was to provide an overview of the anatomy and role
of intrinsic foot muscles, implications of intrinsic weakness and evaluate the different methods used to measure
intrinsic foot muscle strength.
Method: Literature was sourced from database searches of MEDLINE, PubMed, SCOPUS, Cochrane Library, PEDro
and CINAHL up to June 2012.
Results: There is no widely accepted method of measuring intrinsic foot muscle strength. Methods to estimate toe
flexor muscle strength include the paper grip test, plantar pressure, toe dynamometry, and the intrinsic positive
test. Hand-held dynamometry has excellent interrater and intrarater reliability and limits toe curling, which is an
action hypothesised to activate extrinsic toe flexor muscles. However, it is unclear whether any method can actually
isolate intrinsic muscle strength. Also most methods measure only toe flexor strength and other actions such as toe
extension and abduction have not been adequately assessed. Indirect methods to investigate intrinsic muscle
structure and performance include CT, ultrasonography, MRI, EMG, and muscle biopsy. Indirect methods often
discriminate between intrinsic and extrinsic muscles, but lack the ability to measure muscle force.
Conclusions: There are many challenges to accurately measure intrinsic muscle strength in isolation. Most studies
have measured toe flexor strength as a surrogate measure of intrinsic muscle strength. Hand-held dynamometry
appears to be a promising method of estimating intrinsic muscle strength. However, the contribution of extrinsic
muscles cannot be excluded from toe flexor strength measurement. Future research should clarify the relative
contribution of intrinsic and extrinsic muscles during intrinsic foot muscle strength testing.
}, year = {2012}, journal = {Journal of Foot and Ankle Research}, volume = {5}, pages = {29}, issn = {1757-1146}, url = {http://www.jfootankleres.com/content/pdf/1757-1146-5-29.pdf}, doi = {10.1186/1757-1146-5-29}, }