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Original Research
Influence of Maximal Running Shoes
on Biomechanics Before and After a 5K Run
Christine D. Pollard,*
†
PhD, PT, Justin A. Ter Har,
†‡
BS, J.J. Hannigan,
†
PhD, ATC,
and Marc F. Norcross,
‡
PhD, ATC
Investigation performed at the OSU-Cascades FORCE Laboratory, Bend, Oregon, USA
Background: Lower extremity injuries are common among runners. Recent trends in footwear have included minimal and maximal
running shoe types. Maximal running shoes are unique because they provide the runner with a highly cushioned midsole in both the
rearfoot and forefoot. However, little is known about how maximal shoes influence running biomechanics.
Purpose: To examine the influence of maximal running shoes on biomechanics before and after a 5-km (5K) run as compared with
neutral running shoes.
Study Design: Controlled laboratory study.
Methods: Fifteen female runners participated in 2 testing sessions (neutral shoe session and maximal shoe session), with 7 to
10 days between sessions. Three-dimensional kinematic and kinetic data were collected while participants ran along a 10-m
runway. After 5 running trials, participants completed a 5K treadmill run, followed by 5 additional running trials. Variables of interest
included impact peak of the vertical ground-reaction force, loading rate, and peak eversion. Differences were determined by use of
a series of 2-way repeated-measures analysis of variance models (shoe time).
Results: A significant main effect was found for shoe type for impact peak and loading rate. When the maximal shoe was com-
pared with the neutral shoe before and after the 5K run, participants exhibited an increased loading rate (mean ±SE: pre–maximal
shoe, 81.15 body weights/second [BW/s] and pre–neutral shoe, 60.83 BW/s [P<.001]; post–maximal shoe, 79.10 BW/s and post–
neutral shoe, 61.22 BW/s [P¼.008]) and increased impact peak (pre–maximal shoe, 1.76 BW and pre–neutral shoe, 1.58 BW [P¼
.004]; post–maximal shoe, 1.79 BW and post–neutral shoe, 1.55 BW [P¼.003]). There were no shoe time interactions and no
significant findings for peak eversion.
Conclusion: Runners exhibited increased impact forces and loading rate when running in a maximal versus neutral shoe. Because
increases in these variables have been associated with an increased risk of running-related injuries, runners who are new to running
in a maximal shoe may be at an increased risk of injury.
Clinical Relevance: Understanding the influence of running footwear as an intervention that affects running biomechanics is
important for clinicians so as to reduce patient injury.
Keywords: highly cushioned shoes; impact forces; loading rate
Lower extremity injuries have consistently been problem-
atic for runners regardless of footwear. Taunton and
colleagues
17,18
reported that over a 13-week training
period, 30%of runners incurred a running-related injury,
most commonly patellofemoral pain, iliotibial band friction
syndrome, and plantar fasciitis. Since the inception of the
cushioned running shoe, its fundamental purpose has been
to protect the foot in an effort to reduce running-related
injuries. Despite significant advances in shoe technology
over the past 50 years, the rate of sustaining a running-
related injury has remained relatively stable.
11
Numerous variations of running shoes have been devel-
oped to accommodate different types of runners, running
styles, and running conditions. Footwear manufacturers
have modified the basic components of their running shoe
models to accommodate these differences, including mid-
sole cushioning and heel-toe drop. Historically, running
shoes fell into 1 of 3 cushioning classifications: (1) neutral,
(2) stability, and (3) motion control. In general, individuals
with a high amount of pronation were directed to a motion
control shoe, those with a moderate amount of pronation
*Address correspondence to Christine D. Pollard, PhD, PT, Program in
Kinesiology, FORCE Laboratory, Oregon State University–Cascades,
1500 SW Chandler Avenue, Bend, OR 97701, USA (email: christine.
pollard@osucascades.edu).
†
Program in Kinesiology, Oregon State University–Cascades, Bend,
Oregon, USA.
‡
School of Biological and Population Health Sciences, Oregon State
University, Corvallis, Oregon, USA.
The authors declared that they have no conflicts of interest in the
authorship and publication of this contribution.
Ethical approval for this study was obtained from the Oregon State
University Research Protection Program.
The Orthopaedic Journal of Sports Medicine, 6(6), 2325967118775720
DOI: 10.1177/2325967118775720
ªThe Author(s) 2018
1
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were directed to a stability shoe, and those with a minimal
amount of pronation, or individuals who supinated, were
directed to a neutral shoe. Up until the past 7 years, tradi-
tional running shoes tended to have a heel-toe drop, which
refers to the difference between the heel elevation and fore-
foot elevation of the midsole, of greater than 10 mm.
In 2009, the minimalist shoe, defined by very little cush-
ioning and heel drop, became popular among runners.
4
Popularity of these shoes spiked largely because their ben-
efits were espoused by shoe manufacturers and authors of
popular-press books,
12
who claimed that a lack of cushion-
ing would reduce injuries by promoting a more natural
forefoot-strike pattern.
10
However, popularity of minimal
shoes has declined, largely due to research suggesting that
adopting a forefoot-strike pattern does not decrease injury
risk, improve running economy, or reduce the impact peak
or loading rate of the vertical ground-reaction force.
6
Research continues to examine how transitioning from a
traditional shoe to a minimal shoe influences running style,
lower extremity biomechanics, and risk for injury.
7,15,19
At about the same time that minimal shoe popularity was
rising, a company called Hoka One One introduced a highly
cushioned “maximal” running shoe, a stark contrast to the
minimal shoe. Currently, there is no academic definition of a
maximal shoe, but in industry, the defining feature is
increased cushioning of the midsole. Since 2010, maximal
shoes have slowly gained popularity, with more than 20 var-
iations of maximal running shoes now on the market.
Conceptually, this increase in cushioning is thought to
improve shock attenuation and reduce the risk of injury.
Anecdotally, runners have expressed in the popular press
that maximal running shoes reduce or eliminate running-
related pains that often appear several miles into their run.
However, despite increased popularity of maximal shoes in
the marketplace, no research to date has investigated the
effect of a maximal shoe on biomechanical variables associ-
ated with injury, including the loading rate and impact
peak of the vertical ground-reaction force
2,13,14
and peak
eversion of the rearfoot.
14
Therefore, the primary purpose
of this study was to examine the effect of a maximal run-
ning shoe versus a neutral running shoe on lower extremity
running biomechanics before and after a 5-km (5K) run. We
hypothesized that the maximal shoe would result in lower
vertical impact peak and loading rates, but there would be
no change in peak ankle eversion, compared with a neutral
shoe. We also hypothesized that the impact peak and load-
ing rate would increase after the 5K run in the traditional
neutral shoe but not in the maximal shoe.
METHODS
Participants
Participants were 15 female recreational runners (age
range, 23-51 years; mean age, 34 years) who ran a mini-
mum of 15 miles per week and had not run in a minimal
shoe for the 6 months prior to the study. Before participat-
ing in the study, all participants were running in some form
of traditional running shoe, including rearfoot control and
neutral shoes. All runners considered themselves heel-
strikers, which is described as a runner who strikes his or
her heel to the ground first when running (vs midfoot-
striker or forefoot-striker). We focused on heel-strikers, as
it is estimated that 90%of recreational runners have this
footstrike pattern.
3,8
In addition, our study required that
runners had not had an injury within the past month that
limited their running for more than 1 week,
21
were not
pregnant, and did not have any neurological or vascular
disorders. All participants signed an informed consent
document approved by the institutional review board at
Oregon State University prior to participation on the first
day of testing.
Instrumentation
Kinematic data were collected by use of a Vicon 8-camera 3-
dimensional motion analysis system (Oxford Metrics Ltd)
at a sampling frequency of 250 Hz. The cameras were
interfaced to a microcomputer and placed around a floor-
embedded force platform (Advanced Mechanical Technolo-
gies Inc). The force platform (1000 Hz) was interfaced to the
same microcomputer that was used for kinematic data col-
lection via an analog to digital converter. This interface
allowed for synchronization of kinematic and kinetic data.
Procedures
Participants attended the biomechanics laboratory for 2
separate testing sessions, with 7 to 10 days between ses-
sions. For one of the testing sessions, the participants wore
a neutral running shoe (New Balance 880: drop, 10.1 mm;
heel height, 33.3 mm; forefoot height, 23.2 mm), and for the
other testing session, they wore a maximal shoe (Hoka One
One Bondi 4: drop, 6.9 mm; heel height, 41.6 mm; forefoot
height, 34.7 mm) (Figure 1). The order of shoes worn was
randomized across participants. The procedures were the
same for each testing session.
Prior to biomechanical data collection, participants’
height and mass were recorded. Reflective markers
(14-mm spheres) were placed bilaterally over the following
anatomic landmarks: the first and fifth metatarsal heads,
distal interphalangeal joint of the second toe, medial and
lateral malleoli, medial and lateral femoral epicondyles,
Figure 1. Hoka One One maximal running shoe and New
Balance traditional neutral running shoe used in this study.
2Pollard et al The Orthopaedic Journal of Sports Medicine
greater trochanters, and iliac crests. A single marker was
placed on the joint space between the fifth lumbar and the
first sacral spinous processes. Quadrads of rigid reflective
tracking markers were attached bilaterally to the partici-
pant’s thigh and leg with a custom adhesive taping system.
In addition, triads of rigid reflective tracking markers were
placed bilaterally on the heel counter of the shoe. Markers
were always placed by the same researcher (J.A.T.), who had
several years of biomechanics laboratory experience placing
markers. After marker placement, the participant was asked
to stand in the center of the calibration area so we could
collect a static calibration trial. Once the calibration trial
was captured, all markers were removed except those on the
quadrads and triads as well as the iliac crest, anterior supe-
rior iliac spine, and fifth lumbar/first sacral markers.
The participants completed 5 successful running trials for
their dominant leg (defined as the leg they prefer to use
when kicking a soccer ball). The participants were allowed
3 to 5 practice trials in order to become familiar with the
procedures and instrumentation. For each trial, participants
ran toward the force plate from a distance of about 7 m and
continued to run for about 3 m beyond the force plate. They
were asked to run at a pace that was considered a “natural
running pace,” and this pace was used for all running trials
(before and after the 5K run and during each data collection
session). We measured and controlled for their pace by using
timing gates placed along the runway. Running trials were
considered successful if the participant was able to contact
the specified foot entirely on the force plate.
Following completion of the 5 running trials, each par-
ticipant was taken to a treadmill located in the same labo-
ratory. The participant was asked what her average pace
was for a 5K run (in minutes per mile) and was given 2
minutes to warm up on the treadmill at her pace of choice.
After the 2-minute warm-up, the treadmill pace was gradu-
ally ramped up to the testing pace over a 30-second duration.
Once the treadmill pace was set, the participant ran at that
pace for the 5K, and all reflective markers remained on the
participant during the run. After the participant completed
the treadmill run, she was immediately walked back to the
capture area in the biomechanics laboratory. At that time,
the participant performed 5 successful running trials for the
dominant leg as she had done prior to the 5K treadmill run.
Data Analysis
Coordinate data were digitized in Vicon Workstation soft-
ware (Oxford Metrics Ltd). Kinematic data were filtered by
use of a fourth-order, zero-lag, Butterworth 12-Hz, low-
pass filter, while kinetic data were filtered with a fourth-
order, zero-lag, Butterworth 50-Hz, low-pass filter.
16
Visual3D software (C-Motion Inc) was used to quantify
3-dimensional ankle joint kinematics. Joint kinematic
properties were calculated by use of a joint coordinate sys-
tem approach. Peak eversion angle was defined as the max-
imum ankle joint angle in the frontal plane during stance
phase. The method for calculating average vertical loading
rate was consistent with that described by Willy and
Davis,
20
which entailed the middle 60%of the vertical
ground-reaction force curve from heel-strike to the vertical
impact peak. These calculations were made with custom
Excel software (Microsoft Corp).
Statistical Analysis
Variables of interest included the impact peak of the verti-
cal ground-reaction force, loading rate normalized by body
weight (BW), and peak ankle eversion. Differences were
determined via a series of 2-way repeated-measures analy-
sis of variance (ANOVA) (shoe time) (P.05). When
significant differences were found, post hoc comparisons
were made with paired ttests (P.05).
RESULTS
Although no significant shoe time interactions were
found, we noted a significant main effect for shoe type for
loading rate and impact peak. When the maximal shoe was
compared with the neutral shoe before and after the 5K
run, participants exhibited increased loading rate (mean
±SE: pre–maximal shoe, 81.15 ±17.08 BW/s; pre–neutral
shoe, 60.83 ±12.58 BW/s [P<.001]; post–maximal shoe,
79.10 ±19.07 BW/s; post–neutral shoe, 61.22 ±13.88 BW/s
[P¼.008]) (Figure 2) and increased impact peak (pre–
maximal shoe, 1.76 ±0.21 BW; pre–neutral shoe, 1.58 ±
0.14 BW [P¼.004]; post–maximal shoe, 1.79 ±0.21 BW;
post–neutral shoe, 1.55 ±0.16 BW [P¼.003]) (Figure 3).
No main effect was found for time for loading rate or impact
peak. Furthermore, there was no significant difference in
peak eversion between shoe types (pre–maximal shoe,
10.92±3.94; pre–neutral shoe, 11.1±3.38[P<.001];
post–maximal shoe, 13.42±4.84; post–neutral shoe, 14.6
±3.93[P¼.008]).
DISCUSSION
The aim of this study was to examine the effect of maximal
running shoes on lower extremity running biomechanics
before and after a 5K run compared with neutral running
shoes. Despite the popularity of maximal running shoes, we
Figure 2. Loading rate comparison between the traditional
neutral running shoe condition and the maximal running shoe
condition following a 5K run. Error bars represent standard
error. A significant difference was found between shoe types,
P.05. BW, body weight.
The Orthopaedic Journal of Sports Medicine Maximal Running Shoe Biomechanics 3
believe this is the first scientific investigation reported in
the literature to make such a comparison. Contrary to our
hypothesis, the impact peak and loading rate were greater
in the maximal shoe compared with the traditional neutral
shoe. No differences were seen in peak rearfoot eversion.
The majority of recreational runners are classified as
heel-strikers,
3,8
who generally exhibit two distinct vertical
ground-reaction force peaks: an impact peak and an overall
peak (Figure 4).
9
The impact peak is of clinical interest, as
high impact peaks have been associated with common
running-related injuries such as plantar fasciitis and tibial
stress fractures.
13,14
Baltich and colleagues
1
examined the
influence of midsole cushioning on the vertical impact peak
in 93 recreational runners and found that runners exhibited
increased vertical impact forces when wearing softer mid-
sole shoes. The investigators suggested that participants
either were “bottoming out” in the soft midsole condition
or were modifying their lower extremity stiffness. In the
post–data collection discussions for the current study, par-
ticipants reported they could “really feel” the extra cushion-
ing of the maximal shoe, and many reported that the shoes
felt “springy.” As such, we doubt that participants were
“bottoming out” but rather were relying more heavily on the
shoe to attenuate impact forces, which in turn resulted in a
higher impact peak. As previously discussed, a higher
impact peak could place runners at a greater risk of devel-
oping an injury.
13,14
However, it is important to note that
the high impact peak occurs with heel-strike and likely
causes increased loads to the tibia, calcaneus, and plantar
fascia. The increased midsole cushioning likely does not
increase loading of the metatarsals; however, we were not
able to confirm this under the current study design.
In this study, we found that runners displayed a greater
loading rate when wearing a maximal shoe compared with
the neutral shoe. A higher loading rate, which represents
the slope of the vertical ground-reaction force prior to the
impact peak (Figure 4), has been associated with a higher
risk of developing a running-related injury.
13,14
Thus, sim-
ilar to impact peak, higher loading rates in the maximal
shoe may place a runner at an increased risk of developing
an injury.
We also hypothesized that the impact peak and loading
rate would increase after the 5K run in the traditional neu-
tral shoe but not in the maximal shoe. This hypothesis was
based on anecdotal reports from recreational runners in the
community, who reported “feeling the extra cushion” after 2
to 3 miles into their run. However, we found that the 5K
had no influence on the impact peak or loading rate in
either shoe condition, indicating that neither a brief accom-
modation period nor muscular fatigue likely influenced
these kinetic variables.
In addition to examining kinetics, we were also inter-
ested in whether the maximal shoe influenced peak ever-
sion, since this is another biomechanical variable that has
been associated with running-related injuries.
14
The max-
imal shoe is unique in that it offers a highly cushioned
midsole, but manufacturers claim that it also provides a
considerable amount of motion control and stability
because of its wide rearfoot base of support. The maximal
shoe midsole/outsole used in this study was wider than the
neutral shoe, particularly in the rearfoot portion of the shoe
(maximal shoe: forefoot width, 109 mm and rearfoot width,
96 mm; neutral shoe: forefoot width, 103 mm and rearfoot
width, 80 mm). However, our findings revealed no differ-
ence in peak eversion between the neutral running shoe
and the maximal running shoe condition. Therefore, it
appears that there is no difference in the influence of a
maximal shoe versus a neutral shoe when participants are
running over solid surface in a laboratory setting.
Finally, because recent studies have found that runners,
over time and training, may modify their heel-strike pat-
tern to a midfoot- or forefoot-strike pattern when transi-
tioning from a neutral shoe to a minimal shoe,
5
we
conducted a post hoc analysis of all running trials to deter-
mine whether our participants modified their foot-strike
pattern in the maximal shoe condition. This post hoc anal-
ysis consisted of viewing all maximal shoe running trials in
Vicon software and identifying which portion of the foot hit
the force plate first. We found that all participants contin-
ued to exhibit a heel-strike pattern across all conditions.
Figure 4. Example of vertical ground-reaction force trajectory
for the stance phase of a runner classified as a heel-striker.
Key variables of this trajectory are identified.
Figure 3. Comparison of impact peaks between the tradi-
tional neutral running shoe condition and the maximal running
shoe condition following a 5K run. Error bars represent
standard error. A significant difference was found between
shoe types, P.05.
4Pollard et al The Orthopaedic Journal of Sports Medicine
A limitation of this study is that the maximal shoe con-
dition was novel to the participants. The observed differ-
ences were not changed by the 5K run; however, we did not
assess whether these differences persisted over a greater
duration of exposure to the shoe. Allowing runners to
gradually transition or adapt to the shoe over a period of
several weeks may yield different results. Placing markers
directly on the shoes limited our ability to quantify true
ankle eversion. In addition, the exclusion of male runners
limits our findings to only healthy female runners within
the given age range. A final limitation is related to test-
retest reliability. Our kinematic model is commonly used
in the running biomechanics research reported in the lit-
erature; however, this model is most reliable for measur-
ing sagittal plane kinematics. Future studies should
examine how runners adapt to running in a maximal shoe
over a period of time such as 6 weeks.
CONCLUSION
Runners who were classified as heel-strikers exhibited
increased impact forces and loading rate when running in
a maximal shoe compared with a traditional neutral shoe.
Because increases in these variables have been associated
with an increased risk of running-related injuries, runners
who are new to running in a maximal shoe may be at an
increased risk of injury. Therefore, runners should consider
this potential increased risk for injury when switching from
a neutral shoe to a maximal shoe; however, further work is
necessary to better understand the longer term impact of
this type of footwear.
REFERENCES
1. Baltich J, Maurer C, Nigg BM. Increased vertical impact forces and
altered running mechanics with softer midsole shoes. PLoS One.
2015;10(4):e0125196.
2. Davis IS, Bowser BJ, Mullineaux DR. Greater vertical impact loading
in female runners with medically diagnosed injuries: a prospective
investigation. Br J Sports Med. 2016;50(14):887-892.
3. de Almeida MO, Saragiotto BT, Yamato TP, Lopes AD. Is the rearfoot
pattern the most frequent foot stike pattern among recreational shod
distance runners? Phys Ther Sport. 2015;16:29-33.
4. Coetzee DR, Albertus Y, Tam N, Tucker R. Conceptualizing minimal-
ist footwear: an objective definition. JSportsSci. 2018;36(8):
949-954.
5. Fredricks W, Swank S, Teisberg M, Hampton B, Ridpath L, Hanna JB.
Lower extremity biomechanical relationships with different speeds in
traditional, minimalist, and barefoot footwear. J Sports Sci Med. 2015;
14:276-283.
6. Hamill J, Gruber AH. Is changing footstrike pattern beneficial to
runners? J Sport Health Sci. 2017;6(2):146-153.
7. Hollander K, Arqubi-Wollesen A, Reer R, Zech A. Comparison of
minimalist footwear strategies for simulating barefoot running: a
randomized crossover study. PLoS One. 2015:10(5):e0125880.
8. Larsen P, Higgins E, Kaminski J, et al. Foot strike patterns of recrea-
tional and sub-elite runners in a long-distance road race. J Sports Sci.
2011;29:1665-1673.
9. Laughton CA, McClay Davis I, Hamill J. Effect of strike pattern on
orthotic intervention on tibial shock during running. J Appl Biomech.
2003;19:153-168.
10. Lieberman DE, Venkadesan M, Werbel WA, et al. Foot strike patterns
and collision forces in habitually barefoot versus shod runners.
Nature. 2010;463:531-535.
11. Lopes AD, Hespanhol LC, Yeung SS, Pena Costa LO. What are the
main running related musculoskeletal injuries? Sports Med. 2012;
42(10):892-905.
12. McDougal C. Born to Run, A Hidden Tribe, Superathletes, and the
Greatest Race the World Has Never Seen. New York, NY: Vintage
Books; 2009.
13. Milner CE, Ferber R, Pollard CD, Hamill J, Davis IS. Biomechanical
factors associated with tibial stress fracture in female runners. Med
Sci Sports Exerc. 2006;38:323-328.
14. Pohl MB, Mullineaux DR, Milner CE, Hamill J, Davis IS. Biomechanical
predictors of retrospective tibial stress fractures in runners.
J Biomech. 2008;41:1160-1165.
15. Rice HM, Jamison ST, Davis IS. Footwear matters: influence of foot-
wear and foot strike on load rates during running. Med Sci Sports
Exerc. 2016;48:2462-2468.
16. Robertson DGE, Dowling JJ. Design and responses of Butterworth
and critically damped digital filters. J Electromyogr Kinesiol. 2003;
13(6):569-573.
17. Taunton JE, Ryan MB, Clement DB, McKenzie DC, Lloyd-Smith DR,
Zumbo BD. A retrospective case-control analysis of running injuries.
Br J Sports Med. 2002;36:95-101.
18. Taunton JE, Ryan MB, Clement DB, McKenzie DC, Lloyd-Smith DR,
Zumbo BD. A prospective study of running injuries: the Vancouver
Sun Run “In Training” clinics. Br J Sports Med. 2003;37:239-244.
19. Warne JP, Smyth BP, Fagan JO, et al. Kinetic changes during a six-
week minimal footwear and gait-retraining intervention in runners.
J Sports Sci. 2017;35:1538-1546.
20. Willy RW, Davis IS. Kinematic and kinetic comparison of running in
standard and minimalist shoes. Med Sci Sports Exerc. 2014;46:
318-323.
21. Yamato TP, Saragiotto BT, Lopes AD. A consensus definition of
running-related injury in recreational runners: a modified Delphi
approach. J Orthop Sports Phys Ther. 2015;45(5):375-380.
The Orthopaedic Journal of Sports Medicine Maximal Running Shoe Biomechanics 5
