Static Range of Motion of the First Metatarsal in the Sagittal and Frontal Planes

Abstract

The first metatarsal and medial cuneiform form an important functional unit in the foot, called “first ray”. The first ray normal range of motion (ROM) is difficult to quantify due to the number of joints that are involved. Several methods have previously been proposed. Controversy exists related to normal movement of the first ray frontal plane accompanying that in the sagittal plane. The objective of this study was to investigate the ROM of the first ray in the sagittal and frontal planes in normal feet. Anterior-posterior radiographs were done of the feet of 40 healthy participants with the first ray in a neutral position, maximally dorsiflexed and maximally plantarflexed. They were digitalized and the distance between the tibial malleolus and the intersesamoid crest in the three positions mentioned was measured. The rotation of the first ray in these three positions was measured. A polynomic function that fits a curve describing the movement observed in the first ray was obtained using the least squares method. ROM of the first ray in the sagittal plane was 6.47 (SD 2.59) mm of dorsiflexion and 6.12 (SD 2.55) mm of plantarflexion. ROM in the frontal plane was 2.69 (SD 4.03) degrees of inversion during the dorsiflexion and 2.97 (SD 2.72) degrees during the plantarflexion. A second-degree equation was obtained, which represents the movement of the first ray. Passive dorsiflexion and plantarflexion of the first ray were accompanied by movements in the frontal plane: 0.45 degrees of movement were produced in the frontal plane for each millimeter of displacement in the sagittal plane. These findings might be useful for the future design of instruments for clinically quantifying first ray mobility.

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

“…Moreover, it reflects the combined movement of the first ray in the sagittal and frontal planes. A mathematical formula describing a 'normal curve' of the first ray static ROM has been recently reported [21]. This formula was used to design the new instrument to measure the dorsal and plantar mobility of the first ray.…”

“…When a participant was included in the study, radiographs were done using the modified Coleman's test described by Fritz and Prieskorn to quantify the first ray maximum dorsiflexion and plantarflexion [26]. Previously, blocks (2 to 5 mm thick) were progressively placed under the first metatarsal or the lesser metatarsals to quantify the maximum dorsiflexion and plantarflexion, respectively (Figure 2), with the participant in a standing position [21]. Three anterior-posterior (A-P) radiographs of the foot were obtained, with the first ray maximally dorsiflexed, maximally plantarflexed and in a neutral position, using the aforementioned blocks.…”

“…In a recent study a mathematical formula describing a 'normal curve' of the first ray static ROM has been reported [21]. This formula was used to design a new instrument to measure the dorsiflexion and plantarflexion of the first ray (patented in Spain with patent number ES201500721, manufactured and distributed by Fresco Podología S.L., Barcelona, Spain).…”

“…19, x FOR PEER REVIEW 4 of 16 thick) were progressively placed under the first metatarsal or the lesser metatarsals to quantify the maximum dorsiflexion and plantarflexion, respectively(Figure 2), with the participant in a standing position[21].…”

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

“…Dorsal FRM has been quantified in a large number of studies. 27,30,31,46,48,49,52,53,71 The methods include serial radiographs, 1,18,49 mechanical devices, 28,52,64 or by means of a manual stress test examination, which over the past 30 years has morphed into quantifying FRM with a handheld ruler. 41,42,49,53,73 Though no standards currently govern the testing procedure, clinicians usually impose a dorsally directed force to the first metatarsal head and record linear movement as displacement.…”