A comparison of external plantar loading and in vivo local metatarsal deformation wearing two different military boots.

The introduction of the M90 boot with a more flexible outer sole to military recruits in Sweden was accompanied by an increase in second metatarsal stress fractures. This study compared the new boot with the previous, stiffer model. A combination of external plantar pressure measurement (two subjects) and an in vivo measurement of dorsal metatarsal strain (six subjects) using strain gauge instrumented staples was implemented. Walking in both boot models resulted in increased plantar pressure under the heads of the lesser metatarsals and generally decreased loading under the remainder of the foot. Dorsal metatarsal tension increased for subjects wearing the new boot throughout a walking protocol.

[1]  V. Frankel,et al.  Fatigue behavior of adult cortical bone: the influence of mean strain and strain range. , 1981, Acta orthopaedica Scandinavica.

[2]  Ronald L.Valmassy,et al.  Clinical biomechanics of the lower extremities , 1996 .

[3]  E. Isakov,et al.  Dynamic loading on the human musculoskeletal system -- effect of fatigue. , 1998, Clinical biomechanics.

[4]  Peter R. Cavanagh,et al.  In-shoe plantar pressure measurement: a review , 1992 .

[5]  D B Clement,et al.  Stress fractures in athletes , 1987, The American journal of sports medicine.

[6]  J. Willson,et al.  Plantar loading and cadence alterations with fatigue. , 1999, Medicine and science in sports and exercise.

[7]  B. Nigg,et al.  Mechanical energy contribution of the metatarsophalangeal joint to running and sprinting. , 1997, Journal of biomechanics.

[8]  N. Sharkey,et al.  Bone strain and microcracks at stress fracture sites in human metatarsals. , 2000, Bone.

[9]  N. Sharkey,et al.  Strain and loading of the second metatarsal during heel-lift. , 1995, The Journal of bone and joint surgery. American volume.

[10]  C Milgrom,et al.  Stress fractures in military recruits. A prospective study showing an unusually high incidence. , 1985, The Journal of bone and joint surgery. British volume.

[11]  A M McBryde,et al.  Stress fractures in runners. , 1982, Orthopedics.

[12]  A. Lundberg,et al.  Effects of fatigue and load variation on metatarsal deformation measured in vivo during barefoot walking. , 2002, Journal of biomechanics.

[13]  D. Carter,et al.  Cyclic mechanical property degradation during fatigue loading of cortical bone. , 1996, Journal of biomechanics.

[14]  A Arndt,et al.  An in vitro comparison of bone deformation measured with surface and staple mounted strain gauges. , 1999, Journal of biomechanics.

[15]  N. Sharkey,et al.  Strains in the metatarsals during the stance phase of gait: implications for stress fractures. , 1999, The Journal of bone and joint surgery. American volume.

[16]  N J Mansfield,et al.  The apparent mass of the human body exposed to non-orthogonal horizontal vibration. , 1999, Journal of biomechanics.

[17]  S. Orava,et al.  Stress Fractures in Athletes , 1987, International journal of sports medicine.

[18]  S J Dixon,et al.  The shock attenuation characteristics of four different insoles when worn in a military boot during running and marching. , 1999, Gait & posture.

[19]  T. Gross,et al.  A mechanical model of metatarsal stress fracture during distance running , 1989, The American journal of sports medicine.

[20]  C. Milgrom,et al.  Prevention of stress fractures using custom biomechanical shoe orthoses. , 1999, Clinical orthopaedics and related research.

[21]  T J Beck,et al.  Stress fracture in military recruits: gender differences in muscle and bone susceptibility factors. , 2000, Bone.

[22]  R. Recker,et al.  The Impact of Lifestyle Factors on Stress Fractures in Female Army Recruits , 2001, Osteoporosis International.

[23]  I A Stokes,et al.  Forces acting on the metatarsals during normal walking. , 1979, Journal of anatomy.