Reliability of doming and toe flexion testing to quantify foot muscle strength

Abstract

BackgroundQuantifying the strength of the intrinsic foot muscles has been a challenge for clinicians and researchers. The reliable measurement of this strength is important in order to assess weakness, which may contribute to a variety of functional issues in the foot and lower leg, including plantar fasciitis and hallux valgus. This study reports 3 novel methods for measuring foot strength – doming (previously unmeasured), hallux flexion, and flexion of the lesser toes.MethodsTwenty-one healthy volunteers performed the strength tests during two testing sessions which occurred one to five days apart. Each participant performed each series of strength tests (doming, hallux flexion, and lesser toe flexion) four times during the first testing session (twice with each of two raters) and two times during the second testing session (once with each rater). Intra-class correlation coefficients were calculated to test for reliability for the following comparisons: between raters during the same testing session on the same day (inter-rater, intra-day, intra-session), between raters on different days (inter-rater, inter-day, inter-session), between days for the same rater (intra-rater, inter-day, inter-session), and between sessions on the same day by the same rater (intra-rater, intra-day, inter-session).ResultsICCs showed good to excellent reliability for all tests between days, raters, and sessions. Average doming strength was 99.96 ± 47.04 N. Average hallux flexion strength was 65.66 ± 24.5 N. Average lateral toe flexion was 50.96 ± 22.54 N.ConclusionsThese simple tests using relatively low cost equipment can be used for research or clinical purposes. If repeated testing will be conducted on the same participant, it is suggested that the same researcher or clinician perform the testing each time for optimal reliability.

Early-Stage Diabetic Neuropathy Reduces Foot Strength and Intrinsic but Not Extrinsic Foot Muscle Size

“…A doming test (DOM) was used to evaluate the muscles controlling the medial longitudinal arch (MLA) while a toe flexion test was used to simultaneously evaluate great toe flexion (GTF) and lateral toe flexion (LTF) strengths. All tests were performed based on previously published methodology [31,34,35]. Briefly, the DOM was performed on a custom-built apparatus.…”

“…It is possible that the unfamiliarity of this movement combined with the observed intrinsic muscle atrophy in DPN could have resulted in varying intrinsic muscle activation patterns and/or compensations from extrinsic muscles (e.g., TA). Subjects from both groups may need multiple days of practice with this movement to be fully accustomed to it [31]. Due to the lack of strength difference between groups, only a moderate correlation with QP, and the insufficient time to master the movement, further research on DOM is likely needed before it can be used as a clinical tool to diagnose or monitor DPN progression.…”

“…The strength of the smaller foot muscles has not been evaluated. A few previous studies by our group and others have proposed functional strength testing protocols for evaluating distal foot strength [31][32][33][34][35], but these have not yet been applied to DPN. Foot strength testing in combination with US imaging may provide insight into the manner in which DPN affects atrophy and weakness [12].…”

Walking in Minimalist Shoes Is Effective for Strengthening Foot Muscles

“…Three measures of foot muscle strength were collected: GT, lateral toes (LT) flexion, and doming. All measurements were conducted on custom-built apparatuses using reliable techniques (GT ICC, 0.903; GT SEM, 0.703 kg; LT ICC, 0.924; LT SEM, 0.655 kg; doming ICC, 0.949; doming SEM, 0.883 kg) (27). The apparatuses and data collection procedures were described in detail previously (27).…”

“…All measurements were conducted on custom-built apparatuses using reliable techniques (GT ICC, 0.903; GT SEM, 0.703 kg; LT ICC, 0.924; LT SEM, 0.655 kg; doming ICC, 0.949; doming SEM, 0.883 kg) (27). The apparatuses and data collection procedures were described in detail previously (27). To ensure repeatable foot placement and alignment with the dynamometer used for toe flexion, during the first day of testing, each subject's foot was traced onto a piece of paper which rested on top of the platform.…”