Lack of Influence of Muscular Performance Parameters on Spatiotemporal Adaptations With Increased Running Velocity

Abstract

This study aimed to analyse the influence of muscular performance parameters on spatio-temporal gait characteristics during running when gradually increasing speed. 51 recreationally trained male endurance runners (age: 28 ± 8 years) voluntarily participated in this study. Subjects performed a battery of jumping tests (squat jump, countermovement jump, and 20 cm drop jump), and after that, the subjects performed an incremental running test (10 to 20 km/h) on a motorized treadmill. Spatio-temporal parameters were measured using the OptoGait system. Cluster k-means analysis grouped subjects according to the jumping test performance, by obtaining a group of good jumpers (GJ, n = 19) and a group of bad jumpers (BJ, n = 32). With increased running velocity, contact time was shorter, flight time and step length longer, whereas cadence and stride angle were greater (p < 0.001). No significant differences between groups (p ≥ 0.05) were found at any running speed. The results obtained indicate that increased running velocity produced no differences in spatio-temporal adaptations between those runners with good jumping ability and those with poor jumping ability. Based on that, it seems that muscular performance parameters do not play a key role in spatio-temporal adaptations experienced by recreational endurance runners with increased velocity. However, taken into consideration the well-known relationship between running performance and neuromuscular performance, the authors suggest that muscular performance parameters would be much more determinant in the presence of fatigue (exhausted condition), or in the case of considering other variables such as running economy or kinetic.

Full text

LACK OF INFLUENCE OF MUSCULAR PERFORMANCE
PARAMETERS ON SPATIOTEMPORAL ADAPTATIONS
WITH INCREASED RUNNING VELOCITY
LUIS E. ROCHE-SERUENDO,
1
FELIPE GARCI
´A-PINILLOS,
2
JOANA HAICAGUERRE,
1
ANA V. BATALLER-
CERVERO,
1
VI
´CTOR M. SOTO-HERMOSO,
3
AND PEDRO A
´.LATORRE-ROMA
´N
2
1
San Jorge University, Zaragoza, Spain;
2
Department of Corporal Expression, University of Jaen, Jaen, Spain; and
3
Department of Sport Sciences, University of Granada, Granada, Spain
ABSTRACT
Roche-Seruendo, LE, Garcı
´a-Pinillos,F,Haicaguerre,J,Bataller-
Cervero, AV, Soto-Hermoso, VM, and Latorre-Roma
´n, PA
´.Lack
of influence of muscular performance parameters on spatiotem-
poral adaptations with increased running velocity. J Strength
Cond Res 32(2): 409–415, 2018—This study aimed to analyze
the influence of muscular performance parameters on spatiotem-
poral gait characteristics during running when gradually increas-
ing speed. Fifty-one recreationally trained male endurance
runners (age, 28 68 years) voluntarily participated in this study.
Subjects performed a battery of jumping tests (squat jump, coun-
termovement jump, and 20-cm drop jump), and after that, the
subjects performed an incremental running test (10–20 km$h
21
)
on a motorized treadmill. Spatiotemporal parameters were mea-
sured using the OptoGait system. Cluster k-means analysis
grouped subjects according to the jumping test performance,
by obtaining a group of good jumpers (n= 19) and a group of
bad jumpers (n= 32). With increased running velocity, contact
time was shorter and flight time and step length were longer,
whereas cadence and stride angle were greater (p,0.001).
No significant differences between groups (p$0.05) were
found at any running speed. The results obtained indicate that
increased running velocity produced no differences in spatiotem-
poral adaptations between those runners with good jumping abil-
ity and those with poor jumping ability. Based on that, it seems
that muscular performance parameters do not play a key role in
spatiotemporal adaptations experienced by recreational endur-
ance runners with increased velocity. However, taken into con-
sideration the well-known relationship between running
performance and neuromuscular performance, the authors sug-
gest that muscular performance parameters would be much
more determinant in the presence of fatigue (exhausted condi-
tion) or in the case of considering other variables such as running
economy or kinetic.
KEY WORDS endurance runners, jumping ability, reactive
strength index, running kinematics
INTRODUCTION
Distance running performance is influenced not
only by factors related to oxygen uptake and
utilization but also by factors related to muscle
recruitment and force production (28,29).
Although success in endurance sports requires high maxi-
mal oxygen uptake (V
_
O
2
max), it cannot fully explain all the
measured differences in endurance performance. Simulta-
neous strength and endurance training has been shown to
improve muscle strength, running economy (RE), and dis-
tance running performance without any changes in
V
_
O
2
max (29), suggesting that neuromuscular factors are
also important determinants of endurance running perfor-
mance. In fact, jumping ability has been associated with
short-distance running performance (10,19) and also with
long-distance events (19).
Additionally, the way in which one move (running
biomechanicsinthiscase)canfavororlimithisorher
running performance by influencing RE and efficiency
(1,2,25,34). It is reliant on a complex interaction of factors
that lead to efficient muscular work and result in fast and
effective running gait (2,34). Traditionally, physiological
factors, muscle fiber distribution, age, sex, and anthropo-
metric factors have been found to account for interindivid-
ual variability in RE (2,34). However, RE is also influenced
by biomechanical variables, largely contributed from
ground contact and stride characteristics (31,34)—small
vertical oscillations (1), greater stride angles (31), longer
strides (1), and lower ground reaction forces (17) have been
related to superior RE.
Both neuromuscular and biomechanical parameters
during running are highly influenced by running velocity
(5,18). Increases in running speed lead to greater levels of
neuromuscular engagement (mainly in the hamstring
Address correspondence to Felipe Garcı
´a-Pinillos, fegarpi@gmail.com.
32(2)/409–415
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Ó2017 National Strength and Conditioning Association
VOLUME 32 | NUMBER 2 | FEBRUARY 2018 | 409
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muscles) (18). Likewise, it seems clear that to run faster,
ground contact time (CT) need to be decreased to aid in
repositioning the legs during running (5), whereas step
length (SL) is suggested to increase linearly with running
velocity up to 25 km$h
21
(5). Additionally, increased run-
ning velocity led to a greater hip flexion and lower ankle
flexion at the initial contact, lower knee and ankle flexions
at midstance, and greater hip extension at toe-off (5–7,9).
These differences appear to be totally logical because
lower ankle flexion at the initial contact and lower knee
and ankle flexions at midstance have been associated to
shorter CT (5,9).
However, the question is, are those spatiotemporal
adaptations dependent on muscular performance parame-
ters? As far as the authors know, no previous studies have
investigated whether kinematic alterations (spatiotemporal
adaptations specifically) to increased running velocity differ
between those runners with a good jumping ability and
those without (an indirect way to measure neuromuscular
performance (3)). Therefore, the main goal of this study was
to analyze the influence of muscular performance parame-
ters on spatiotemporal gait characteristics during running
when gradually increasing speed. The authors hypothesize
that runners with good muscular performance will experi-
ence different spatiotemporal adaptations in response to an
increase in running velocity than those with a lower muscu-
lar performance.
METHODS
Experimental Approach to the Problem
Endurance runners performed an incremental running test
and a battery of jumping tests. An analysis of the dynamic of
spatiotemporal gait characteristics at different velocities
during running on a treadmill was performed, as well as to
determine its relationship with the muscular performance
parameters (measured in a laboratory setting). A unilateral
crossover design was used, with all subjects performing the
same protocol and conditions.
Subjects
A group of 51, recreationally trained, male, endurance
runners (6SD age, 28 68 years; age range, 18–40 years;
height, 178 67 cm; body mass, 73 68 kg) voluntarily
participated in this study. All subjects met the inclusion
criteria: (a) older than 18 years; (b) recreationally active
(3–4 running sessions per week, at least once on a tread-
mill); (c) able to run 5-km in less than 25 minutes; and (d)
had not suffered from any injury within the past 6 months
before the data collection. After receiving detailed infor-
mation on the objectives and procedures of the study,
each subject signed an informed consent form to partici-
pate, which complied with the ethical standards of the
World Medical Association’s Declaration of Helsinki
(2013); it was made clear that the subjects were free to
leave the study if they saw fit. The study was approved by
the Ethics Committee of the San Jorge University (Zara-
goza, Spain).
Procedures
The study was conducted in February 2016. At the time of
these observations, the subjects had completed between 2
and 4 months of training. Subjects were cited on 1 specific
day, and they were individually tested (between 16:00 and
21:00 hours). Before all testing, subjects refrained from
severe physical activity for at least 48 hours, and all testing
was at least 3 hours after ingestion of a meal. Tests were
performed with the subjects wearing their usual training
shoes to attain their most typical performance.
Before the running protocol, the subjects performed
a warm-up, which consisted of 10 minutes of continuous
running and 5 minutes of general exercises (high skipping,
leg flexion, jumping exercises, and short bursts of accelera-
tion). Then, the subjects performed a battery of jumping tests
(squat jump [SJ], countermovement jump [CMJ], and 20-cm
drop jump [DJ20]), and after that, the subjects performed an
incremental running test on a motorized treadmill (Salter M-
835; Salter, Int., Barcelona, Spain).
The treadmill protocol was preceded by a standardized
10-minute accommodation program. The subjects were
experienced in running on a treadmill, but anyway, previous
studies (32) on human locomotion have shown that accom-
modation to a new condition occurs in approximately 8 mi-
nutes. The running test started at 10 km$h
21
, and running
speed was increased 1 km$h
21
every 20 seconds (10-second
acclimatization period: 10-second recording period), finish-
ing at 20 km$h
21
for all subjects. The short duration of speed
conditions aimed to minimize the effect of fatigue on run-
ning kinematics and let most of the subjects complete this
speed range (10–20 km$h
21
) at which recreational runners
usually run in both training and competition.
Materials and Testing
Anthropometry. For descriptive purposes, height (cm) and
body mass (kg) were determined using a precision stadiom-
eter and balance (SECA 222 and 634, respectively; SECA,
Corp., Hamburg, Germany). All measurements were taken
with the subjects wearing running shorts and underwear.
Biomechanics. Spatiotemporal parameters were measured
using the OptoGait system (Microgate, Bolzano, Italy),
which was previously validated for the assessment of
spatiotemporal parameters of the gait of young adults,
reporting a high level of correlation with all spatiotemporal
parameters by intraclass correlation coefficients (ICCs)
(0.785–0.952), coefficients of variation (1.66–4.06%), stan-
dard error of measurement (2.17–5.96%), and minimum
detectable change (6.01–16.52%) (20). The 2 parallel bars
of the device system were placed on the side edges of the
treadmill at the same level as the contact surface. This device
was connected to a computer controlled by the researcher.
Data were recorded and averaged for the subsequent
Muscle Performance and Spatiotemporal Parameters
410
Journal of Strength and Conditioning Research
the
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analysis. In accordance with the findings from Brown et al.
(4), limb dominance was not taken into account. Stride
angle, CT, flight time (FT), SL, and stride frequency (SF)
were measured for every step during the treadmill test.
CT (seconds): time from when the foot contacts the
ground to when the toes lift off the ground.
FT (seconds): time from toe-off to initial ground con-
tact of consecutive footfalls of the same foot.
SL (meters): length the treadmill belt moves from toe-
off to initial ground contact in successive steps.
SF (steps$min
21
): number of ground contact events
per minute.
Stride angle (8): angle of the parable tangent derived
from the theoretical arc traced during a stride between
the foot and the ground (31). The theoretical parabola
for the stride angle determination was calculated by the
system through the stride length and the maximal
height of the foot during a stride. The determination
of stride length is described above, and the maximal
height of the foot during a stride was calculated by
the OptoGait system as indicated by Santos-
Concejero et al. (31).
Muscular performance. It is indirectly measured through
jumping test. The CMJ, SJ, and DJ20 (from a 20-cm height
box) were recorded using the same system (OptoGait;
Microgate), a technology previously validated (14). This
device measures the CT on the floor and the FT, using
photoelectric cells. Flight time was used to calculate the
height of the rise using the body’s center of gravity. Subjects
performed 2 trials of every test, with a 15-second recovery
period between them with the best trial being used for the
statistical analysis. Subjects were encouraged to achieve
maximum performance throughout both running and jump-
ing protocols.
Vertical jumping tests are commonly used to evaluate
muscular performance (12,13) and the effectiveness of the
stretch-shortening cycle in runners (10,15). Additionally, the
ability to develop force quickly is a requisite ability in most
sports and the reactive strength index (RSI) has been developed
as a measure of explosive strength and is derived by evaluating
jump height divided by ground CT during the DJ (11). Reactive
strength index was also calculated in the current study.
Statistical Analyses
Descriptive statistics are represented as mean (SD). Tests of
normal distribution and homogeneity (Kolmogorov and
Levene’s test, respectively) were conducted on all data
before analysis. A cluster k-means was performed by group-
ing according to the jumping tests performance (CMJ, SJ,
and DJ20). A 1-way analysis of variance (ANOVA) was per-
formed to compare subgroups (anthropometric characteris-
tic, spatiotemporal, and muscular performance parameters).
A repeated measures ANOVA was performed to determine
the effect of velocity on spatiotemporal parameters for the
whole group and the subgroups created. The reliability of
TABLE 1. Characteristic of participants (mean, SD).*
Variables Males (n= 51) Good jumpers (n= 19) Bad jumpers (n= 32) p
Age (y) 27.56 (7.54) 26.50 (5.02) 28.19 (8.7) 0.442
Height (m) 1.78 (0.07) 1.79 (0.05) 1.77 (0.08) 0.544
Body mass (kg) 73.12 (7.96) 73.68 (6.68) 72.77 (8.74) 0.699
BMI 22.09 (1.82) 23.10 (1.69) 23.09 (1.92) 0.977
*BMI = body mass index.
TABLE 2. Jumping test performance (mean, SD).*
Variables Males (n= 51) Good jumpers (n= 19) Bad jumpers (n= 32) p
CMJ (cm) 33.46 (5.56) 38.86 (3.84) 30.26 (3.59) ,0.001
DJ20 (cm) 29.02 (4.76) 32.61 (4.85) 26.88 (3.19) ,0.001
SJ (cm) 27.45 (5.59) 32.69 (4.43) 24.35 (3.49) ,0.001
RSI 122.41 (30.62) 141.78 (25.24) 110.89 (27.83) ,0.001
*CMJ = countermovement jump; DJ20 cm = drop jump from a 20-cm height; SJ = squat jump; RSI = reactive strength index (height
reached during DJ20/contact time).
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jumping ability test (CMJ, DJ20, and SJ) was assessed using
ICCs between test-retest and confidence interval (CI).
RESULTS
Test-retest reliability analysis of jumping tests performed in
this study shows an ICC of 0.986 (95% CI, 0.972–0.993) for
the CMJ, ICC of 0.963 (95% CI, 0.927–0.981) for the SJ, and
ICC of 0.883 (95% CI, 0.637–0.963) for the DJ20.
Table 1 shows the anthropometric characteristic of sub-
jects for the whole group and for the subgroups created
according to the vertical jump performance. No between-
group differences (p$0.05) were found in any variable
(age, height, body mass, body mass index).
Cluster k-means analysis grouped subjects according to
the jumping tests performance, by obtaining a group of good
jumpers (GJ, n= 19) and a group of bad jumpers (BJ, n= 32).
Between-group differences (Table 2) were found in CMJ
(+8.6 cm; p,0.001), DJ20 (+5.93 cm; p,0.001), SJ
(+8.34 cm; p,0.001), and RSI (30.89; p,0.001).
The effect of velocity on temporal gait parameters is
shown in Figure 1. With increased running velocity, CT was
shorter and FT was longer (significant changes in every +1
Figure 1. Temporal parameters (contact time and flight time) with increased running velocity for the whole group and groups created according to jumping
ability.
Figure 2. Spatiotemporal parameters with increased running velocity for the whole group and groups created according to jumping ability.
Muscle Performance and Spatiotemporal Parameters
412
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km$h
21
step; p,0.001) with no significant differences
between groups at any running speed (p$0.05).
The effect of running velocity on spatiotemporal variables
(SL, SF, and stride angle) is presented in Figure 2. With
increased running velocity, SL was longer and SF and stride
angle were greater (p,0.001), with no significant differ-
ences between groups at any running speed (p$0.05).
DISCUSSION
This study aimed to analyze the influence of muscular
performance parameters on spatiotemporal adaptations
during running at different velocities (incremental, from
10 to 20 km$h
21
).Themainfindingofthecurrentstudy
was the lack of between-group differences (GJ vs. BJ) in
the kinematic adaptations experienced by subjects when
they increased running velocity. With increased running
velocity, even though in a nonfatigued condition, CT was
shorter, FT and SL were longer, and SF and stride angle
were greater, but no differences were found between
groups of GJ and BJ—an indirect measure of muscular
performance (3).
Regarding spatiotemporal adaptations with increased run-
ning velocity, the results obtained in the current study
reinforce the findings of previous studies. It seems clear that
to run faster, FT needs to be increased and CT needs to be
decreased to aid in repositioning the legs during running (5).
Based on that relationship, SF also needs to be increased to
run faster (26). More controversial is the dynamic of SL when
velocity increases. It has been suggested that SL increases
linearly with running velocity up to 25 km$h
21
(5), which is
in consonance with our findings (SL increased over the pro-
tocol up to 20 km$h
21
). Changes in these parameters during
running have been suggested as the influencing factors
on impact shock (16,23,24) and, thereby, on the risk of
injury (21–23). Changes in spatiotemporal parameters at a fixed
speed can alter electromyography and kinetics (8,16,21,22,33)
and, thereby, the magnitude and rate of impact force loading
during the stance phase of running (23). Running injuries may
be associated with that magnitude and rate of impact force
loading during the stance phase of running (23).
As for the stride angle, the available information is quite
limited, which makes comparisons much more difficult. A
previous study by Santos-Concejero et al. (31) points to
stride angle as an easily obtainable measure that reveals
greater potential for running performance and RE than
other biomechanical variables. The current study shows
that stride angle increases with an increased running veloc-
ity, and this finding is in consonance with the results re-
ported by that study (31). The authors suggest that this
adaptation may be a marker of the ability of the athlete
to efficiently maximize FT and minimize CT with effective
energy transfer during ground contact. Greater stride an-
gles would lead athletes to experience shorter CT, allowing
a better RE (27,31). As indicated by previous studies (31),
this phenomenon could be the result of an early contrac-
tion of the muscles involved in the movement of a stride
during the stance phase, leading the center of mass to be
projected forward more efficiently. All these changes in
spatiotemporal parameters have also been associated to
athletic performance. For example, when SF is manipulated
during running, the musculoskeletal system alters the
mechanical behavior of its spring system (26), and this
yields an effect on parameters related to RE and efficiency
(34). Increased SF results in decreased ground CT, vertical
displacement of center of mass, and leg length variation
(compression) (26,34). Likewise, CT appears to be a strong
and direct determinant of leg stiffness (26)—decreasing CT
yielded an increase in leg stiffness and vice versa (26).
On the other hand, the results obtained in the current
study indicated that there were no differences in the
aforementioned spatiotemporal adaptations with increased
running velocity between groups with GJ and BJ, respec-
tively (an indirect measure of muscular performance (3)).
Although the effect of running velocity on spatial and tem-
poral parameters seems clear, the involvement of neuro-
muscular factors on these adaptations has not yet been
determined. It seems well established that neuromuscular
factors are important determinants of endurance running
performance (10,19,28,29). As indicated by Pruyn et al.
(30), higher levels of lower-body stiffness seem to be
advantageous for athletes when performing rapid and
(or) repeated stretch-shorten cycle movements (i.e., run-
ning). Both muscle and tendon properties may be impor-
tant in this transfer of energy during human locomotion.
Stored energy in these springs (muscle and tendon) could
conceivably reduce muscle activation and spare energy
expenditure, thus improving RE (10), and that is why the
authors hypothesized that runners would experience dif-
ferent spatiotemporal adaptations according to their mus-
cular performance. Nevertheless, this study indicates that
spatiotemporal adaptations to an incremental running pro-
tocol are not determined by muscular parameters, at least
in these conditions: amateur endurance runners perform-
ing an incremental test in the absence of fatigue. The au-
thors suggest that muscular performance parameters might
be much more determinant in the presence of fatigue (ex-
hausted condition) or in the case of considering other var-
iables, such as RE or running kinetics.
Finally, some limitations must be taken into consider-
ation when interpreting these results. First, sex differences
were not assessed, with female subjects not participating in
the current study. Second, the lack of data related to
parameters that might play an important role in this
relationship, such as ground reaction forces (running
kinetic) and RE measures. Notwithstanding these limita-
tions, the current study highlights the dynamic of spatio-
temporal parameters during an incremental running test in
amateur endurance runners (parameters frequently used by
coaches and clinicians for assessing athletes) and deter-
mines the lack of influence of neuromuscular parameters on
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spatiotemporal adaptations with increased running velocity
(inamateurrunnersandintheabsenceoffatigue).
In conclusion, the results obtained indicate that
increased running velocity produced no differences in
spatiotemporal adaptations between those runners with
good jumping ability and those with badjumping ability.
However, taking into consideration the well-known rela-
tionship between running performance and neuromuscular
performance, the authors suggest that muscular perfor-
mance parameters might be much more determinant in
the presence of fatigue (exhausted condition) or in the case
of considering other variables, such as RE or running
kinetics.
PRACTICAL APPLICATIONS
From a practical point of view, these data suggest that
coaches and sport scientists should be prudent to establish
relationships between running kinematics and neuromus-
cular parameters through an isolated assessment. It seems
that muscular performance parameters do not play a key
role in spatiotemporal adaptations experienced by recrea-
tional endurance runners with increased velocity (at least,
under these conditions: lack of fatigue effects and amateur
runners).
ACKNOWLEDGMENTS
This paper is part of the thesis of the first author L. E. Roche-
Seruendo The thesis plan is registered in the PhD program in
Biomedicine (B11/56/1) of Universidad de Granada (Granada,
Spain). This work was supported by the Spanish Ministry of
Economy and Competitiveness together with the European
Fund for Regional Development, Project “AVISaMe” ref.
DEP2015-70980-R (MINECO/FEDER, EU). The authors
thank all the athletes who participated in the research
and Fisio-Zaragoza for facilitating installation and resour-
ces without any interest. The authors declare no conflict of
interests.
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