Injury-Reduction Effectiveness of Prescribing Running Shoes on the Basis of Foot Arch Height: Summary of Military Investigations
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[ research report ]
JOSEPH J. KNAPIK, ScD1 • DANIEL W. TRONE, PhD2 • JUSTE TCHANDJA, MPH3 • BRUCE H. JONES, MD1
Injury-Reduction Effectiveness
of Prescribing Running Shoes
on the Basis of Foot Arch Height:
Summary of Military Investigations
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T
he first clinical use of footprints (plantar shapes) may be as high arched, broad (low arched), and
attributed to Colonel R. I. Harris and Major T. Beath, who normal,34,36 as shown in FIGURE 1.
Perhaps the first to apply plantar
used them to evaluate foot problems in Canadian soldiers.
Copyright © 2014 Journal of Orthopaedic & Sports Physical Therapy®. All rights reserved.
shapes to running shoes was Dr Peter
Recruits and soldiers stepped on a rubber mat that provided Cavanagh, who recommended that static
footprints, in conjunction with dynamic
a visualization of their footprint and the Subsequently, these footprints were used foot flexibility measurements, could be
amount of static weight-bearing pressure to determine a number of clinical indices, used as part of a 10-point plan to find the
exerted on different parts of the foot.19,35 which included plantar shapes classified most appropriate running shoe.8,10 Subse-
quently, several running-shoe authorities
in the popular running magazine Run-
TTSTUDY DESIGN: Secondary analysis of 3 foot arch, respectively. The control group received
randomized controlled trials. a stability shoe regardless of plantar shape.
ner’s World suggested that plantar shapes
Journal of Orthopaedic & Sports Physical Therapy®
could assist in determining if individuals
TTOBJECTIVE: Analysis of studies that examined Injuries during basic training were assessed from
whether prescribing running shoes on the basis outpatient medical records. overpronated, underpronated, or had
of foot arch height influenced injury risk during TTRESULTS: Meta-analyses that pooled results normal pronation during running.9,12,13
military basic training. of the 3 investigations showed little difference Beginning in the late 1980s and into
TTBACKGROUND: Prior to 2007, running maga- between the experimental and control groups in the 2000s, running shoes were largely
zines and running-shoe companies suggested that the injury rate (injuries per 1000 person-days) classified based on their intended pur-
imprints of the bottom of the feet (plantar shape) for either men (summary rate ratio = 0.97; 95% pose and related to plantar shapes. It was
could be used as an indication of foot arch height confidence interval [CI]: 0.88, 1.06) or women
assumed that plantar shapes were reflec-
and that this could be used to select individually (summary rate ratio = 0.97; 95% CI: 0.85, 1.08).
When injury rates for specific types of running
tive of foot arch height and could assist in
appropriate types of running shoes.
selecting individually appropriate types
TTMETHODS: Similar studies were conducted in
shoes were compared, there were no differences.
TTCONCLUSION: Selecting running shoes based
of running shoes, with the goal of reduc-
US Army (2168 men, 951 women), Air Force (1955
men, 718 women), and Marine Corps (840 men, on arch height had little influence on injury risk in ing the likelihood of injury.2-5,14,30,39 Indi-
571 women) basic training. After foot examinations, military basic training. viduals with a foot shape reflecting a low
TTLEVEL OF EVIDENCE: Prevention, level 1b.
recruits were randomized to either an experimental arch were presumed to have greater rear-
or a control group. Recruits in the experimental foot and midfoot mobility that allowed
J Orthop Sports Phys Ther 2014;44(10):805-812.
group selected or were assigned motion-control,
Epub 25 August 2014. doi:10.2519/jospt.2014.5342 the foot to pronate excessively during the
stability, or cushioned shoes to match their plantar
shape, which represented a low, medium, or high TTKEY WORDS: footprints, foot type, pronation stance phase of running. For these indi-
viduals, “motion-control” shoes were rec-
1
US Army Institute of Public Health, Portfolio of Epidemiology and Disease Surveillance, Aberdeen Proving Ground, MD. 2Naval Health Research Center, San Diego, CA. 3559th
Medical Group, Joint Base San Antonio, Lackland, TX. This study was funded by the Defense Safety Oversight Council. The authors certify that they have no affiliations with or
financial involvement in any organization or entity with a direct financial interest in the subject matter or materials discussed in the article. The views expressed herein are the
views of the authors and do not reflect the official policy of the Department of the Army, the Department of Defense, or the US government. Address correspondence to Dr Joseph
Knapik, US Army Institute of Public Health, Portfolio of Epidemiology and Disease Surveillance, ATTN: MCHB-IP-DI, Aberdeen Proving Ground, MD 21010. E-mail: joseph.j.knapik.
ctr@mail.mil t Copyright ©2014 Journal of Orthopaedic & Sports Physical Therapy®
journal of orthopaedic & sports physical therapy | volume 44 | number 10 | october 2014 | 805
44-10 Knapik.indd 805 9/16/2014 5:03:41 PM
[ research report ]
ommended, because it was assumed that
these shoes could control excessive foot
motion. Individuals with a plantar shape
reflecting a high arch were assumed to
have rigid or inflexible feet that impacted
the ground with greater force and did not
pronate sufficiently. These individuals
were directed toward “cushioned” shoes,
which presumably increased shock ab-
sorption by providing for more pronation FIGURE 1. Plantar shapes showing high (A), low (B), and normal (C) arch heights.
and cushioning to soften ground impact.
Individuals with a foot shape reflecting
a normal arch height were assumed to
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impact the ground with less force and
to have an appropriate amount of foot
pronation. A “stability” shoe, which was
presumed to have moderate cushioning
and motion-control characteristics, was
recommended for these individuals.32
Copyright © 2014 Journal of Orthopaedic & Sports Physical Therapy®. All rights reserved.
Prior to 2007, the military services
had generally followed the recommen-
dations of the shoe companies. In fact,
many military post exchanges had wall
displays advertising various types of
running shoes categorized by foot shape
(FIGURE 2). During basic training inpro-
cessing, new recruits could select or
were assigned a running shoe based on
Journal of Orthopaedic & Sports Physical Therapy®
the plantar shape of their foot. However,
whether shoes based on foot arch height
reduced injuries had not been tested in
a randomized controlled trial. Conse-
quently, the Military Training Task Force FIGURE 2. A typical display of running shoes in a military post exchange, showing the shoes based on their
of the US Department of Defense Safety purpose and plantar shapes.
Oversight Council requested that this be
examined in the military services, and METHODS studies, 3 models of New Balance shoes
studies were subsequently conducted in were used, 1 matching each foot type. The
I
the Army, Air Force, and Marine Corps n 2007, independent studies were Army study included 19 different models
basic training.22,26,27 conducted in Army, Air Force, and Ma- of shoes from 5 different shoe companies,
The purpose of this paper was to rine Corps basic training. The design of but shoes for the recruits in the experi-
analyze and summarize the data from the 3 studies was identical. Recruits were mental group were still assigned based
previously published basic training randomized into either an experimental on plantar shapes. The shoe brands and
studies that examined the effectiveness or control group and trained side by side models used in each study are shown in
of assigning running shoes on the ba- in the same military units. The recruits TABLE 1.
sis of plantar shape, assumed to reflect in the experimental group were assigned All recruits’ plantar shapes were
foot arch height, in reducing injury. For motion-control, stability, or cushioned evaluated by having them step onto
this purpose, we performed a secondary running shoes, based on their plantar the acrylic surface of a device shown in
analysis of the data from 3 randomized shape, which represented a low, medium, FIGURE 3. Recruits were instructed to
controlled trials.22,26,27 Our goal was to or high foot arch, respectively. The re- stand with equal weight on each foot.
fully synopsize the results of the inves- cruits in the control group were provided The device contained a mirror that re-
tigations and to provide evidence-based with a stability shoe regardless of plantar flected the underside of the foot, thus
conclusions. shape. In the Air Force and Marine Corps providing a visual image of the footprint
806 | october 2014 | volume 44 | number 10 | journal of orthopaedic & sports physical therapy
44-10 Knapik.indd 806 9/16/2014 5:03:42 PM
regularly incorporates data on all am-
Running Shoes Used in the bulatory (outpatient) encounters that
TABLE 1
Military Footwear Studies occur within military treatment facili-
ties and those outside military treat-
Experimental Group Control Group ment facilities that are paid for by the
Service Motion-Control Shoe Stability Shoe Cushioned Shoe Stability Shoe Department of Defense. The Defense
Army26 Asics Gel Foundation 7 Asics Gel 1120 Asics Gel Cumulus New Balance 767 Medical Surveillance System provided
Brooks Addiction 7 Asics Gel 2120 Brooks Radius 6 visit dates and ICD-9 codes for all out-
Saucony Grid Stabil 6 Brooks Adrenaline GTS6 Nike Air Pegasus patient medical visits within the recruit
New Balance 857* Brooks Adrenaline GTS7 Saucony Grid Trigon 4 training time frame for each recruit vol-
Nike Structure Triax New Balance 644
Nike Air Max Moto* New Balance 755
unteer. An injury case was defined as a
Saucony Grid Omni 5 recruit who had at least 1 specific ICD-9
New Balance 717 code included in 1 of 3 injury indices:
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New Balance 767 the comprehensive injury index, overuse
Air Force22 New Balance 587 New Balance 498 New Balance 755 New Balance 498 injury index, and training-related inju-
Marine Corps27 New Balance 587 New Balance 767 New Balance 881 New Balance 767 ry index. These indices and the ICD-9
*For 2 shoes, the Army classification differed from those of Runner’s World and the manufacturer. codes used in each have been previously
One shoe was the New Balance 857, which the Army classification listed as a motion-control shoe but
defined.23 The comprehensive injury in-
Runner’s World and the manufacturer listed as a stability shoe; the other was the Nike Air Max Moto,
listed in the Army classification as a stability shoe but by Runner’s World and the manufacturer as a dex captures all ICD-9 codes related to
Copyright © 2014 Journal of Orthopaedic & Sports Physical Therapy®. All rights reserved.
cushioned shoe. injuries, classically defined as physical
damage to the body as a result of energy
exchanges.15,16 The overuse injury index
captures the subset of musculoskeletal
injuries presumably resulting from cu-
mulative microtrauma (overuse), such
as stress fractures, stress reactions,
tendinitis, bursitis, fasciitis, arthralgia,
neuropathy, radiculopathy, shin splints,
Journal of Orthopaedic & Sports Physical Therapy®
synovitis, sprains, strains, and musculo-
skeletal pain (not otherwise specified).
The training-related injury index is a
subset of the overuse injury index that
FIGURE 3. Device used to evaluate plantar shape: individual standing on device (A) and reflective surface showing is limited to lower extremity overuse in-
high-arched individual (B).
juries and is routinely used to compare
injury rates among Army basic training
and the proportion of the plantar sur- cruits did not complete training and were locations.
face coming into contact with the acrylic either discharged because of unsuitability The Comprehensive Meta-Analysis
surface. Two testers independently clas- for military service or transferred to an- statistical package Version 2 (Biostat, Inc,
sified each recruit’s arch height as high, other unit because they needed addition- Englewood, NJ) was used to perform a
medium, or low, based on a template al time to successfully complete required secondary analysis of the data from the
(FIGURE 1). Disagreements were discussed training activities. For these recruits, the 3 studies using meta-analysis. For each
between raters and a final decision was amount of time they were in training in injury index in each of the 3 studies, the
made. The between-rater reliability of their initial unit was obtained from ad- person-time injury incidence rate (IIR)
the plantar-shape evaluations (n = 66) ministrative training records. Individuals was calculated as the sum of recruits with
was formally determined using kappa were followed for injuries until gradua- 1 or more injuries divided by the sum of
statistics and was found to be 0.91 for tion, discharge, or assignment to another total recruit time in training, multiplied
both feet.27 unit. by 1000 to obtain injuries per 1000 per-
Basic training in the Army, Air Force, In all 3 military services, informa- son-days. A fixed meta-analysis model
and Marine Corps was conducted for 9, 6, tion on injuries that occurred during was used that employed the IIR ratios
and 12 weeks, respectively, during which training was obtained from the De- of the control and experimental groups
the assigned running shoes were worn fense Medical Surveillance System. The (control IIR/experimental IIR) and their
throughout physical training. Some re- Defense Medical Surveillance System 95% confidence intervals (CIs) to pro-
journal of orthopaedic & sports physical therapy | volume 44 | number 10 | october 2014 | 807
44-10 Knapik.indd 807 9/16/2014 5:03:42 PM[ research report ]
Injury Incidence Rates and Meta-analyses of Experimental
TABLE 2
and Control Groups in 3 Military Studies
Men Women
Injury Injury
Injury Index/ Incidence Rate Ratio Summary Incidence Rate Ratio Summary
Service/Group n Rate* (CG/EG)† Rate Ratio†‡ P Value§ I2 n Rate* (CG/EG)† Rate Ratio†‡ P Value§ I2
Comprehensive injury 0.97 (0.88, 1.06) .63 0% 0.97 (0.85, 1.08) .10 57%
index
Army 0.99 (0.86, 1.13) 0.96 (0.82, 1.12)
CG 1079 5.95 483 10.87
EG 1089 6.04 468 11.37
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Air Force 0.91 (0.77, 1.09) 0.84 (0.68, 1.04)
CG 913 6.43 345 10.89
EG 1042 7.04 373 12.96
Marine Corps 0.99 (0.80, 1.22) 1.21 (0.94, 1.57)
CG 432 5.72 257 6.00
EG 408 5.76 314 4.96
Copyright © 2014 Journal of Orthopaedic & Sports Physical Therapy®. All rights reserved.
Overuse injury index 0.95 (0.85, 1.06) .77 0% 0.93 (0.82, 1.06) .21 35%
Army 0.96 (0.82, 1.13) 0.94 (0.79, 1.11)
CG 1079 4.37 483 8.87
EG 1089 4.55 468 9.16
Air Force 0.89 (0.74, 1.08) 0.81 (0.63, 1.02)
CG 913 5.25 345 8.50
EG 1042 5.86 373 10.55
Marine Corps 1.02 (0.79, 1.31) 1.18 (0.83, 1.66)
CG 432 4.14 257 3.29
EG 408 4.06 314 2.80
Journal of Orthopaedic & Sports Physical Therapy®
Training-related injury index 0.90 (0.80, 1.02) .71 0% 0.95 (0.83, 1.09) .21 37%
Army 0.91 (0.77, 1.08) 0.99 (0.83, 1.18)
CG 1079 3.99 483 8.80
EG 1089 4.38 468 8.59
Air Force 0.85 (0.69, 1.05) 0.79 (0.61, 1.04)
CG 913 3.94 345 6.68
EG 1042 4.62 373 8.41
Marine Corps 0.98 (0.75, 1.28) 1.18 (0.79, 1.77)
CG 432 3.56 257 2.03
EG 408 3.63 314 1.72
Abbreviations: CG, control group; EG, experimental group.
*Injuries per 1000 person-days.
†
Values in parentheses are 95% confidence interval.
‡
From meta-analyses.
§
Q-statistic.
duce a summary IIR ratio and summary erogeneity and smaller values less. In was possible to examine IIRs between
95% CI that reflected the pooled results calculating I2, negative values were equal different shoe makes and models using
from all 3 studies. The homogeneity of to zero,20 indicating very little heteroge- a chi-square test for person-time.1 Each
the IIR ratios from the individual studies neity. Men and women were analyzed shoe was compared to each other shoe
was assessed using the Q-statistic and the separately in all calculations, due to large (2-by-2 analysis). The comprehensive
I2 statistic. The I2 statistic indicated the differences in IIRs. injury index was used for this analysis,
percent of heterogeneity among studies, Because the Army study utilized a and shoes that were used by at least 40
with larger values indicating more het- number of different running shoes, it recruits were included.
808 | october 2014 | volume 44 | number 10 | journal of orthopaedic & sports physical therapy
44-10 Knapik.indd 808 9/16/2014 5:03:43 PMInjury Incidence Rates and Meta-analyses (Comprehensive Injury Index) of
TABLE 3
Low- and High-Arched Individuals Wearing Different Types of Running Shoes
Men Women
Injury Injury
Plantar Shape/ Incidence Summary Incidence Summary
Service/Shoe Type n Rate* Rate Ratio† Rate Ratio†‡ P Value§ I2 n Rate* Rate Ratio † Rate Ratio†‡ P Value§ I2
Low 0.91 (0.68, 1.23) .70 0% 0.90 (0.60, 1.35) .55 0%
Army 0.95 (0.63, 1.43) 0.72 (0.39, 1.34)
SS 137 5.88 38 8.91
MCS 119 6.21 43 12.32
Air Force 0.79 (0.48, 1.30) 0.94 (0.46, 1.90)
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SS 79 6.83 23 13.61
MCS 134 8.67 37 14.52
Marine Corps 1.17 (0.51, 2.66) 1.28 (0.56, 2.96)
SS 27 5.44 20 6.44
MCS 35 4.67 37 5.02
High 0.89 (0.69, 1.15) .57 0% 0.94 (0.71, 1.24) .78 0%
Copyright © 2014 Journal of Orthopaedic & Sports Physical Therapy®. All rights reserved.
Army 0.81 (0.57, 1.16) 1.01 (0.70, 1.48)
SS 162 5.78 81 11.93
CS 176 7.13 81 11.76
Air Force 0.99 (0.64, 1.51) 0.78 (0.42, 1.43)
SS 119 6.93 41 9.73
CS 181 7.03 64 12.48
Marine Corps 0.97 (0.48, 1.93) 0.92 (0.51, 1.64)
SS 34 5.46 48 5.64
CS 45 5.66 57 6.17
Journal of Orthopaedic & Sports Physical Therapy®
Abbreviations: CS, cushioned shoe; MCS, motion-control shoe; SS, stability shoe.
*Injuries per 1000 person-days.
†
Values in parentheses are 95% confidence interval. Ratio: SS/MCS (low) or SS/CS (high).
‡
From meta-analyses.
§
Q-statistic.
RESULTS TABLE 3 shows a comparison of injury both men (P = .14-.99) and women (P =
rates among individuals with high and .44-.99).
T
ABLE 2 shows the IIRs, the IIR ra- low arches who wore different types of
tios, and the meta-analysis summa- running shoes. Recruits with plantar DISCUSSION
ry IIR ratios with the summary 95% shapes indicative of low arches who wore
T
CIs. Results from the independent stud- stability shoes had injury rates that were he results of this analysis indi-
ies, as well as the pooled results, indicat- similar to those who wore motion-con- cated that there was little difference
ed that there was little difference between trol shoes. Recruits with plantar shapes in injury rates between military
the experimental and control groups, re- indicative of high arches who wore sta- recruits who wore a running shoe as-
gardless of the injury index employed. bility shoes had injury rates similar to signed on the basis of plantar-shape foot
The Q-statistic indicated that the results those who wore cushioned shoes. The arch height compared to those who were
of the 3 studies were relatively homoge- Q-statistic and I2 statistic indicated that assigned a stability shoe regardless of
neous for both men and women. The I2 the data from the 3 studies were relatively plantar shape. The 3 studies used a ran-
statistic indicated virtually no heteroge- homogeneous for both men and women. domized prospective design, the same
neity among studies for any injury index FIGURE 4 shows the IIRs (comprehen- injury definitions, and examined indi-
among the men. Among the women, the sive injury index) for shoes that were viduals who trained side by side in the
I2 statistic indicated somewhat more het- worn by at least 40 recruits in the Army same units in the well-standardized basic
erogeneity, but this was still relatively low study. There was little difference in the training environment. The results were
for the 2 overuse injury indices. injury rates based on the shoes worn for relatively homogeneous for the 3 studies
journal of orthopaedic & sports physical therapy | volume 44 | number 10 | october 2014 | 809
44-10 Knapik.indd 809 9/16/2014 5:03:43 PM[ research report ]
were a number of methodological differ-
16
ences between the Fort Drum project and
the basic training studies reported here.
14
The basic training studies involved a pre-
Injury Incidence Rate, Injuries per 1000 Person-Days
12.16 scription based only on plantar shape,
12 11.62
10.78 10.76 whereas the observational study involved
a prescription based on foot arch height
10
and foot flexibility. In the basic training
studies of a population of recruits, it was
8
ensured that the recruits were given the
6.49 correct shoe and the shoe was worn dur-
5.94 5.83 5.90
6 ing training. The Fort Drum investiga-
4.66 4.58 tion involved soldiers who were given
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4 the shoe prescription, but there was no
n= n= n= n= n= n= n= n= n= n= follow-up to determine whether they
1390 124 118 108 69 42 604 64 42 41
2 had actually purchased and/or worn the
recommended shoe. In fact, a survey in-
0 volving a convenience sample of 122 Fort
NB 767 Nike Asics 2120 Brooks Nike Air Brooks NB 767 Asics 2120 Nike Air Brooks Drum soldiers (out of an average of 9752
Copyright © 2014 Journal of Orthopaedic & Sports Physical Therapy®. All rights reserved.
Structure GTS7 Pegasus GTS6 Max Moto GTS7
estimated to be on post) found that only
Shoe Make and Model
11% self-reported that they had followed
Men Women
the shoe-prescription advice. The basic
training studies involved a prospective
FIGURE 4. Comparison of injury incidence rates (comprehensive injury index) between different running-shoe shoe prescription involving 2 randomly
makes and models. Abbreviation: NB, New Balance. assigned groups (control and experimen-
tal) training side by side in a standardized
in the meta-analyses. Three different in- those with high-arch feet who wore sta- program, with follow-up for any injury
jury definitions were examined, and the bility shoes. Injury rates were found to occurring during the period of training.
Journal of Orthopaedic & Sports Physical Therapy®
results were similar in all 3 studies and be similar, even for those comparisons The Fort Drum investigation involved a
in the meta-analyses, indicating little ef- looking at match versus mismatch foot retrospective examination of medical vis-
fect on injury rates in those who were or and shoe types. Overall, the results of its to a physical therapy clinic before and
were not assigned shoes on the basis of the meta-analysis suggested a tendency after the shoe program was initiated. A
plantar shape. In addition, similar injury for recruits with low- and high-arch feet number of temporal factors were poten-
rates occurred with the use of several dif- wearing stability shoes to have slightly tial confounders in the Fort Drum proj-
ferent models of running shoes in Army lower injury rates than those wearing ect, and these were discussed at length in
basic training. shoes presumably designed specifically the report.24 The major potential bias was
If injury risk could be reduced by for their foot type (ie, motion-control or a change in the medical surveillance sys-
assigning shoes on the basis of plan- cushioned shoes). tem used to track injuries, which was dis-
tar shape, the largest risk reduction A comprehensive literature search covered after investigating the time point
might be expected between those wear- was performed up to January 2014 to when injuries dramatically decreased. In
ing shoes specifically designed for that find other studies that addressed injuries summary, the advantages of the basic
plantar shape and those wearing shoes among individuals using running shoes training studies were that they (1) used
not designed for that plantar shape. that were assigned based on foot arch a randomized prospective design, (2)
Thus, recruits with low-arch feet who height. Only 1 review33 and 1 observa- provided considerably better knowledge
wore motion-control shoes (presum- tional study24 were found. The review33 about the shoes worn, and (3) involved
ably designed to control for excessive was conducted before the studies report- a more controlled training environment.
pronation) were compared to those with ed here had been published and merely The development of motion-control
low-arch feet who wore stability shoes. noted that no investigations on this topic and cushioned shoes appears to have
Likewise, recruits with high-arch feet existed. The observational investigation24 been based on 2 assumptions: (1) that
who wore cushioned shoes (presumably showed a decrease in serious injuries at individuals with high and low foot arch
designed to provide cushioning and allow Fort Drum, NY after initiation of a run- heights have particular gait mechanics,
more foot pronation) were compared to ning-shoe prescription program. There and (2) that particular shoe characteris-
810 | october 2014 | volume 44 | number 10 | journal of orthopaedic & sports physical therapy
44-10 Knapik.indd 810 9/16/2014 5:03:44 PMtics can adjust or compensate for these feet. This occurred despite the fact that, were 1.04 (95% CI: 0.94, 1.16; Q-statistic,
gait differences such that they more regardless of arch type, motion-control P = .54) for men and 1.07 (95% CI: 0.95,
closely conform to those of individuals shoes attenuated rearfoot motion bet- 1.20; Q-statistic, P = .64) for women. This
with more average arch heights. With ter than cushioned shoes and that cush- analysis supports the earlier ones report-
regard to the first assumption, individu- ioned shoes generally attenuated shock ed here, showing no difference in injury
als with low foot arches were presumed better and allowed more pronation than rates among the control and experimen-
to have disproportionate foot flexibility the motion-control shoes.6,7,11,17 Thus, tal groups when the significant covariates
that allowed the foot to pronate exces- while the shoes performed as expected, were considered.
sively during the stance phase of run- there was little difference in mechanics
ning. Individuals with high foot arch between individuals with low- and high- CONCLUSION
were presumed to have rigid or inflex- arch feet running in these shoes. The
T
ible feet that underpronate and impact military training studies analyzed here he results of the present inves-
the ground with higher forces. However, additionally show that injury rates ap- tigation indicated that selecting or
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studies have shown that when nonsymp- pear to be the same regardless of the type assigning running shoes on the basis
tomatic runners and walkers with high- of shoe worn by individuals with high- or of foot arch type did not reduce injuries
and low-arch feet were tested using the low-arch feet. in military basic training compared to as-
same shoes, there were few arch-related One major advantage of the basic signing a stability shoe regardless of plan-
differences in rearfoot motion or impact training studies was that all recruits were tar shape. In addition, injury rates for
forces.18,21,28,31 Conversely, when previ- evaluated under very similar living and several brands of running shoes were sim-
Copyright © 2014 Journal of Orthopaedic & Sports Physical Therapy®. All rights reserved.
ously injured or symptomatic runners activity conditions. Recruits lived in the ilar during Army basic training. It should
with low and high arches were tested same barracks, consumed meals in simi- be noted that these studies examined
using the same shoes, there were differ- lar dining halls, and performed physical the effect of selecting or assigning run-
ences in running kinematics. Injured or training and other activities together. ning shoes only on the basis of the static
symptomatic runners with low arches Specific operational training activities weight-bearing plantar shape. This was
tended to demonstrate more inversion/ differed in the various military services the practice in basic training when the
eversion and less internal tibial rotation (Army, Air Force, Marine Corps), but the studies were conducted and the method
on the talus during the stance phase of physical training in which the running recommended by popular running maga-
running. Injured or symptomatic run- shoes were used was similar and gener- zines and shoe companies to presumably
Journal of Orthopaedic & Sports Physical Therapy®
ners with high arches had less inversion/ ally consisted of calisthenics, various reduce the risk of injury. Anecdotal ob-
eversion, more internal tibial rotation on movement drills, and running in groups servations during the studies indicated
the talus, more leg stiffness, higher initial of those with similar fitness levels. The that there was a great amount of variety
ground impact forces, and a higher rate findings were similar in all 3 services, of recruit foot sizes and shapes. A single
of initial force development on ground showing no difference between the exper- running shoe is not likely to accommo-
impact.29,37,38 Thus, gait differences as- imental and the control groups in terms date the variety of foot types encountered
sociated with foot type may be more ap- of injury outcomes. in basic training. Consideration should be
plicable to symptomatic and previously Although we did not consider covari- given to providing recruits with a selec-
injured individuals than to those who are ates in the present summary, several were tion of running shoes that at least pro-
not experiencing symptoms or who have considered in the individually reported vide a wide range of lengths and widths,
not been previously injured. investigations.22,26,27 These covariates although shoe selection based on plantar
With regard to the second assump- included age, physical characteristics, shape is not necessary. t
tion, when individuals with high- or physical fitness, and lifestyle characteris-
low-arch feet ran in motion-control or tics (cigarette smoking, prior physical ac- KEY POINTS
cushioned shoes, there was little differ- tivity level, prior injuries, and menstrual FINDINGS: Assigning running shoes on the
ence in kinematics between these 2 foot history). Many of these characteristics basis of the height of the longitudinal
types, including during prolonged run- had been shown to be associated with foot arch did not influence injury rates
ning.6,7 The only variable to differ was injuries in past investigations.25 To see if in military basic combat training. Injury
the instantaneous loading rate (maxi- these factors might have made a differ- rates in military basic training were also
mal instantaneous slope of initial force ence in injury rates, a fixed-model meta- similar regardless of the type of running
development on ground impact), which analysis was performed on the adjusted shoe worn.
was actually higher in the cushioned shoe hazard ratios from the Cox regressions IMPLICATIONS: Selecting the type of run-
(compared with the motion-control shoe) reported in the articles. The pooled ad- ning shoes based on foot arch height
when worn by individuals with low-arch justed hazard ratios from the 3 studies does not appear to be beneficial in
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reducing injury risk in military basic 13. F itz-Hugh S. Prone to trouble? Runner’s World. shoes based on plantar shape. J Strength Cond
training. October 1986;21:44-45. Res. 2009;23:685-697. http://dx.doi.org/10.1519/
CAUTION: These studies only examined 14. Greene W, Fredericksen R. Fall shoe guide. Run- JSC.0b013e3181a0fc63
ner’s World. September 2006;41:99-116. 27. Knapik JJ, Trone DW, Swedler DI, et al. Injury re-
shoe assignments and injuries in US
15. Haddon W, Jr. Advances in the epidemiology of duction effectiveness of assigning running shoes
military basic training, and shoe selec- injuries as a basis for public policy. Public Health based on plantar shape in Marine Corps basic
tion or assignment was based exclusively Rep. 1980;95:411-421. training. Am J Sports Med. 2010;38:1759-1767.
on the shape of the footprint. 16. Haddon W, Jr. Energy damage and the http://dx.doi.org/10.1177/0363546510369548
ten countermeasure strategies. J Trauma. 28. Nachbauer W, Nigg BM. Effects of arch height of
1973;13:321-331. the foot on ground reaction forces in running.
ACKNOWLEDGEMENTS: We would like to thank 17. Hamill J, Bates BT, Holt KG. Timing of lower Med Sci Sports Exerc. 1992;24:1264-1269.
Claudia Coleman and Ryan Steelman for as- extremity joint actions during treadmill running. 29. Nawoczenski DA, Saltzman CL, Cook TM. The
sistance with obtaining references, and Ryan Med Sci Sports Exerc. 1992;24:807-813. effect of foot structure on the three-dimensional
18. Hamill J, Bates BT, Knutzen KM, Kirkpatrick kinematic coupling behavior of the leg and rear
Steelman for editorial review.
GM. Relationship between selected static foot. Phys Ther. 1998;78:404-416.
and dynamic lower extremity measures. Clin 30. New Balance. Arch analysis. Available at:
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