The influence of metatarsal support height and longitudinal axis position on plantar foot loading

      Abstract

      Background:

      Metatarsal supports are effective at decreasing plantar foot pressures at the metatarsal heads, however, little is known about the dependence of this decrease upon height and position.

      Methods:

      Barefoot static stance pressure measurements were recorded during standing in single limb support (n = 22). Two metatarsal support heights (5 mm, 10 mm) were evaluated in six positions at 5 mm increments (0, 5, 10, 15, 20, 25 mm) proximal to the metatarsal heads along the longitudinal axis of the foot. The barefoot condition with no metatarsal support served as the control. Mean force was measured for each test condition. The findings of this study are limited to the barefoot (unshod) condition.

      Findings:

      Mean plantar force decreased significantly under the second metatarsal head with both 5 and 10 mm metatarsal supports compared to the control, and 10 mm metatarsal support compared with 5 mm metatarsal support (P < 0.05) while no statistically significant differences were noted relative to longitudinal axis position.

      Interpretation:

      The results of this study suggest that the thickness of a metatarsal support is a determinant factor in regulating plantar loading. Surprisingly, the longitudinal axis location of a metatarsal support does not appear to be as important as clinically presumed since the data showed that the force decrease was similar for all positions from 5 to 25 mm. Thus, the orthotic induced effect of a metatarsal support seems to have a sizable interaction range that has not previously been reported. We speculate that the metatarsal support’s fulcrum and lift effect can be sustained at a more proximal position due to the foot’s rigidity as a lever and the manner in which a metatarsal support interacts with the plantar aponeurosis.

      Keywords

      To read this article in full you will need to make a payment
      Subscribe to Clinical Biomechanics
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect

      References

        • Chang A.H.
        • Abu-Faraj Z.U.
        • Harris G.F.
        • Nery J.
        • Shereff M.J.
        Multistep measurement of plantar pressure alterations using metatarsal pads.
        Foot Ankle Int. 1994; 15: 654-660
        • Hayda R.
        • Tremaine M.D.
        • Tremaine K.
        • Banco S.
        • Teed K.
        Effect of metatarsal pads and their positioning: a quantitative assessment.
        Foot Ankle Int. 1994; 15: 561-566
        • Hicks J.H.
        The mechanics of the foot. II. The plantar aponeurosis and the arch.
        J. Anat. 1954; 88: 25-30
        • Hodge M.C.
        • Bach T.M.
        • et al.
        Novel Award First Prize Paper. Orthotic management of plantar pressure and pain in rheumatoid arthritis.
        Clin. Biomech. (Bristol, Avon). 1999; 14: 567-575
        • Holmes Jr., G.B.
        • Timmerman L.
        A quantitative assessment of the effect of metatarsal pads on plantar pressures.
        Foot Ankle. 1990; 11: 141-145
        • Hsi W.L.
        • Kang J.H.
        • Lee X.X.
        Optimum position of metatarsal pad in metatarsalgia for pressure relief.
        Am. J. Phys. Med. Rehabil. 2005; 84: 514-520
        • Lapidus P.W.
        Misconceptions about the “springiness” of the longitudinal arch of the foot; mechanics of the arch of the foot.
        Arch. Surg. 1943; 46: 410-421
        • Postema K.
        • Burm P.E.
        • et al.
        Primary metatarsalgia: the influence of a custom moulded insole and a rockerbar on plantar pressure.
        Prosthet. Orthot. Int. 1998; 22: 35-44