Measurement of Dorsal First Ray Mobility: A Topical Historical Review and Commentary

Abstract

Despite evidence that instability of the first ray (first metatarsal and medial cuneiform) alters the loading mechanics of the foot, surprisingly few studies have linked the condition with disorders of the foot. A factor limiting this research is the difficulty associated with measuring first ray mobility (FRM). To quantify dorsal FRM, clinicians and researchers have devised a variety of methods that impose a dorsally directed load, and record displacement. The methods include manual examination, radiographs, mechanical devices, and handheld rulers. Since different methods yield different results; each of these methods is worthy of scrutiny. This article reviews the methods used to quantify dorsal FRM and offers commentary on how the testing procedures could be standardized. The measurement of dorsal FRM informs surgical decisions, orthotic prescriptions, and research design strategies mostly as it pertains to the identification and treatment of first ray hypermobility. This review found sufficient support to recommend continued use of radiographs and mechanical devices for quantifying dorsal displacement, whereas measurements acquired with handheld rulers are prone to the same subjective error attributed to manual examination procedures. Since measures made with radiographs and existing mechanical devices have their own drawbacks, the commentary recommends ideas for standardizing the testing procedure and calls for the development of a next-generation device to measure dorsal FRM. This future device could be modeled after arthrometers that exist and are used to quantify stability at the knee and ankle. Level of Evidence: Level V, expert opinion.

The Validity and Reliability of a New Simple Instrument for the Measurement of First Ray Mobility

“…Obviously, simplicity is an important requisite for any clinical test. Unfortunately, manual examination of the first ray ROM lacks sufficient diagnostic accuracy [8], and may be subject to great inter-rater variability. Therefore, instruments to quantify the mobility of the first ray in a valid and reliable way are needed.…”

“…In spite of these instruments having been used in various studies, [11][12][13][14][15][16] they have some inconveniences such as, for example, being too complex, being large, not quantifying plantarflexion (which would be useful to compare with dorsiflexion), or not reflecting the combined movements of dorsiflexion-inversion and plantarflexion-eversion [4,17]. These are possible reasons why they are not used in daily clinical practice [8]. More simple instruments have been subsequently created aiming at solving some of the aforementioned inconveniences [18,19].…”

Pes Planus Deformity and Its Association With Hallux Valgus Recurrence Following Scarf Osteotomy

“…It has been hypothesized that instability in the medial column of the foot, with subsequent collapse of the arch and rotation of the hallux, may propagate hallux valgus. 6,16,23,24,34 There is a paucity of research investigating any association between pes planus and recurrence of hallux valgus following surgery. One such study reported recurrence in 40% of feet with pes planus compared with 11% of feet without pes planus (odds ratio 5.2).…”

Biomechanical assessment in HAV treatment

“…To assess the fi rs ray, the subtalar joint was placed in a neutral position and the minor metatarsals are hugged with one hand and the 1st metatarsal is mobilized in dorsal fl exion and plantar fl exion. With the help of a goniometer, we assessed the greater range of motion and this will indicate the position of the metatarsal [8,12].…”