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R E S E A R C H Open Access
Effect of microtitanium impregnated tape on the
recovery of triceps surae musculotendinous
function following strenuous running
Jonathan D Hughes
1
, Philip W Fink
3
, David F Graham
2
and David S Rowlands
3,4*
Abstract
We previously reported increased running economy and joint range of motion (ROM) during subsequent exercise
performed 48-h following strenuous exercise while wearing garments containing micro-titanium particles generated
from high-pressure aqueous processing of titanium (AQUA TITAN
TM
). Here we utilised an isolated plantarflexion
triceps surae model and AQUA TITAN-treated flexible tape to determine if dermal application of the micro-titanium
could account for meaningful changes in functional properties of the musculotendinous unit. In a randomised
double-blind crossover, 20 trained men day 1, baseline measures, AQUA TITAN or placebo tape covering the
triceps surae, intermittent high-intensity treadmill running; day 2, rest; day 3, post-stress post-treatment outcome
measures. Outcomes comprised: plantarflexion ROM via isokinetic dynamometry; short latency reflex from
electromyography; Achilles tendon stiffness from isometric dynamometry, ultrasonography (Achilles-medial-
gastrocnemius junction), motion analysis, and force-length modelling. High-intensity exercise with placebo tape
reduced tendon stiffness (−16.5%; 95% confidence limits ±8.1%; small effect size), relative to non-taped baseline,
but this effect was negligible (−5.9%; ±9.2%) with AQUA TITAN (AQUA TITAN-placebo difference −11.3%;
±11.6%). Change in latency relative to baseline was trivial with placebo (1.6%; ±3.8%) but large with
AQUA TITAN (−11.3%; ±3.3%). The effects on ROM with AQUA TITAN (1.6%; ±2.0%) and placebo were
trivial (−1.6% ±1.9%), but the small difference (3.1%; ±2.7%) possibly greater with AQUA TITAN. AQUA
TITAN tape accelerated the reflex response and attenuated reduced Achilles tendon stiffness following
fatiguing exercise. Altered neuromuscular control of tendon stiffness via dermal application of micro-titanium
treated materials may facilitate restoration of musculotendinous contractile performance following prior strenuous
exercise.
Keywords: Tendon compliance; Recovery; Stretch reflex; Tendon tap; Dynamometry
Introduction
There is considerable current interest in research, athletic,
and rehabilitation fields for interventions that can improve
musculotendinous function following fatiguing exercise.
Recently, garments treated with titanium microparticles
(AQUA TITAN™) worn during recovery from simulated
soccer match play or hill running increased subsequent
joint range of motion (ROM) (Wadsworth et al. 2010) and
running economy (Rowlands et al. 2013), respectively, but
the neural, musculotendinous, or other physiological mech-
anisms for these changes were not identified. Increased
ROM and lower metabolic cost during subsequent activity
could be a result of improved musculotendinous function
attributable to changes in tendon compliance and/or
dynamic neuromuscular performance reflected in the short
latency reflex, which contributes to improved contractile
performance during running (Ishikawa and Komi 2007).
Tendon stiffness plays an important role in many
facets of movement. High tendon compliance can en-
hance the storage and release of energy during muscular
contraction (Alexander 2002), while high stiffness maxi-
mizes force transfer (Lichtwark et al. 2007). During
running, maximal muscle forces produced in the
* Correspondence: d.s.rowlands@massey.ac.nz
3
School of Sport and Exercise, Massey University, Palmerston North,
New Zealand
4
School of Sport and Exercise, Massey University Wellington, Wellington,
New Zealand
Full list of author information is available at the end of the article
a SpringerOpen Journal
© 2013 Hughes et al.; licensee Springer. This is an open access article distributed under the terms of the Creative Commons
Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction
in any medium, provided the original work is properly cited.
Hughes et al. SpringerPlus 2013, 2:653
http://www.springerplus.com/content/2/1/653
triceps surae are higher for athletes with stiffer ten-
dons (Hof et al. 2002). In addition, economical runners
possess higher contractile strength and tendon stiffness
indicating that muscle-tendon unit functionality during
running is dependent both on the stiffness of the series
elastic component and on the maximal strength of the
contractile component (Arampatzis et al. 2006). During
recovery from a bout of exhaustive exercise, limb fatigue
reduced subsequent running economy (Hunter and Smith
2007) which may be due to reduced muscle strength and
tendon stiffness (Lichtwark et al. 2007) as occurring in
high-load isometric models (Kay and Blazevich 2009).
In addition to potential changes in tendon function,
AQUA TITAN may also impact on peripheral neuro-
muscular performance. In isolated mice hippocampal
neurons, AQUA TITAN tape reduced the resting mem-
brane potential and action potential frequency (Korte
2008). Since the rate of force development is an important
determinant of muscle-tendon performance (Fukashiro
et al. 1995), altered motor neuron firing rates with AQUA
TITAN could improve unit contractile performance.
To more clearly define and quantify the magnitude of
the effect of AQUA TITAN on musculotendinous func-
tion, a functionally relevant isolated triceps surae model
of plantarflexion was used. Achilles tendon stiffness and
reflex response were studied using dynamometry, mo-
tion analysis, ultrasonography and electromyography be-
fore and 48-h following a strenuous treadmill run (Drust
et al. 2000). We hypothesised that AQUA TITAN tape
would better maintain normal rested baseline muscle-
tendon function in accordance with the trained optima
concept of Lichtwark and Wilson (2007), as represented
by attenuation of reflex function, strength, and stiffness
during recovery from hard running, relative to placebo.
Methods
Twenty trained male team sport athletes competing in
regional level soccer, rugby, or field hockey competition,
aged 26.6 ± 7.8 y (mean ± SD), and with mean body mass
of 81.2 ± 11.3 kg, stature of 179 ± 4.4 cm, and maximum
oxygen uptake of 61.6 ± 7.1 mL·kg
-1
·min
-1
, volunteered
to participate in the study. A sample size of 20 was esti-
mated for the expected effect size on Achilles tendon
stiffness based on effect size estimate drawn from
change in plantarflexion ROM due to AQUA TITAN
of 3.7% (effect size 0.2) (Wadsworth et al. 2010) and
the coefficient of variation for tendon length using
similar procedures (6.1%) (Fletcher et al. 2010), and
the method of sample size for meaningful (effect size)
magnitude-based inference (Hopkins et al. 2009). Po-
tential participants were interviewed and subsequently
excluded if they had a history of Achilles tendinopathy
or lower limb trauma, illness or were currently on an-
algesic medication. All participants were informed in
writing about the potential risks of the study and gave
written informed consent for their participation in the
study, which was performed according to the Declar-
ation of Helsinki and approved by the University’sRe-
search Ethics Committee prior to the start of the
investigation.
Procedure
All participants first completed a treadmill-based assess-
ment of
_
VO
2max
(Wadsworth et al. 2010) followed 1-wk
later by familiarization of the experimental procedures
(Figure 1). Participants performed a double-blind rando-
mised crossover comprising baseline measurements of
joint range of motion (ROM), Achilles tendon stiffness,
short latency reflex, and isokinetic torque, followed by a
40-min treadmill protocol to simulate the physical de-
mands of intermittent high-intensity sport shown previ-
ously to cause leg muscle fatigue and altered contractility
(Drust et al. 2000; Rahnama et al. 2006). The treadmill
speeds for each activity in the protocol were based upon
the speeds observed for each specific movement category
during soccer match-play: walking 6 km·h
-1
,jogging
12 km·h
-1
,cruisingkm·h
-1
and sprinting 21 km·h
-1
.The
protocol was arranged around two identical cycles sepa-
rated by a static recovery period of 90 s. Each cycle con-
sisted of 23 discrete bouts of activity (duration): 6 ×
walking (35.3 s); 6 × jogging (50.3 s); 3 × cruising (51.4 s),
and 8 × sprinting (10.5 s). High-intensity exercise (cruise
and sprint) bouts were separated by low-intensity recovery
(walk and jog), ordered via within-subject randomisation,
and replicated in the second arm of the crossover. Recov-
ery mechanics were assessed 48-h following the run after
an intervening rest day. There was a 10-d washout be-
tween experimental blocks.
All 20 participants completed one trial wearing AQUA
TITAN treated tape and one wearing a placebo tape al-
located by double-blind randomization. Both the AQUA
TITAN and placebo tapes were custom made by Phiten
Co. Ltd. (Kyoto, Japan), using an AQUA TITAN concen-
tration of 540 ml·l
-1
in the treatment tape. AQUA
TITAN is a suspension of titanium nanoparticles in
water (Hirata et al. 2004 Patent 522431). Phiten Co.
Ltd also funded the study but had no other involve-
ment in, or right to approve or disapprove the current
publication. Both tapes were black and covered the en-
tire posterior lower limb from the calcaneus to the
proximal attachments of the medial and lateral gastro-
cnemius (Figure 2a). The tape was applied following
the baseline measures after which it remained in place
for the duration of the intermittent treadmill protocol
and the entire recovery period including all exercise
tests and while sleeping. The blinding code was main-
tained by an external party and revealed to researchers
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only after the analysis was performed. To prevent any
possible mixing, tapes were stored separately.
The effect of the tape was assessed through dynamom-
etry and analysis of the short latency reflex, in that
order. Dynamometry was taken with participants re-
clined in a supine position at a hip angle of 0° (i.e. fully
extended). The foot of the dominant leg was placed
against the footplate of the dynamometer. The lever arm
of the dynamometer was aligned so that the center of
rotation of the dynamometer was aligned with the lateral
malleolus. The initial ankle position was preset at neutral,
0°, mid plantar/dorsiflexion. Maximal plantar flexion iso-
metric torque was sampled at six predefined angles (0, 5,
10, 15, 20 and 25°). Two contractions were performed
with 120 s recovery between efforts. Participants were
instructed to impart force to the foot plate in a gradual
manner until they reach maximal effort around 1 s into
the contraction then to hold that force for the remaining
2 s. Maximal plantar flexion isokinetic torque was sam-
pled at four predefined angular velocities (30, 60, 90 and
120°·s
-1
) through a predetermined range of motion (25°).
Three repetitions at each angular velocity were performed;
each velocity was interspersed with 180 s recovery. The
isometric conditions were used to estimate tendon stiff-
ness, while the isokinetic data was used to measure the
functional changes in the muscle/tendon complex.
Following the dynamometry, changes in the short la-
tency reflex of the medial gastrocnemius muscle were
assessed using a tendon tap method. Participants lay
prone with the ankle at 90º passive dorsiflexion and were
instructed to relax. The Achilles tendon was tapped with
an instrumented reflex hammer operated by hand. This
test was performed three times.
Apparatus
An isokinetic dynamometer (Biodex Medical Systems
System 3, NY, USA) was used to sample isometric ten-
sion and isokinetic torque. Participants were videoed
while performing the dynamometer test using a Casio
Exlim Ex-F1 camera (Casio Computer Co Ltd, Tokyo
Japan) at 30 Hz. Black circles were placed on the Achil-
les insertion at the calcaneus, the medial malleolus and
on the head of the ultrasound transducer (Figure 2b). In
order to assess tendon length, ultrasound images of the
medial gastrocnemius/Achilles tendon musculotendo-
nous junction (MG/AT MTJ) were simultaneously col-
lected at 10 Hz using a Sonosite, MicroMaxx ultrasound
(Sonosite Inc., Bothell, USA).
Torque and position for the dynamometer were col-
lected using an ADI power lab system (PowerLab 4/25,
ADInstruments) at 1000 Hz. The ultrasound data collec-
tion was manually triggered; the trigger also activated a
light emitting diode which was used as a synchronization
event in the video image, and a signal was simultaneously
sent to the power lab system to start data collection. The
video was analyzed to find the first frame in which the
light was visible, and this frame coincided with the first
frame of the ultrasound image, as well as the first sample
from the power lab. Using this method, the video was syn-
chronized to within 1/30 of a second of the ultrasound
and dynamometer.
The locations of the markers in the video and the MTJ
in the ultrasound image were digitized using MaxTRAQ
software (version 2.19-012, Innovision systems Inc.
Columbiaville, MI, USA). The ultrasound probe was
orientated along the longitudinal axis of the MG/AT
MTJ. When the location of the MTJ was ascertained,
Figure 1 Experimental design. Shown is (A) pre-testing, familiarisation measures, and the two crossover blocks, followed by (B, inset) detail of
one of the two 3-d experimental blocks.
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the probe was positioned so that both the superficial
and, importantly, the deep aponeurosis between MG
and Soleus were apparent, ensuring accurate and
reliable identification of the MTJ. To match the sam-
pling frequency of the ultrasound, only every third
frame of the video was digitized. To calculate the loca-
tion of MG/AT MTJ in absolute space, the coordinates
of the MTJ in the ultrasound image were added to the
centre point of the ultrasound probe digitized in the
video.
To examine the short latency reflex, surface electro-
myographic (sEMG) activities of the GM muscles were
recorded from the right leg using bipolar surface elec-
trodes with a 5 mm diameter and a 10 mm fixed inter-
electrode distance (Ambu® Blue Sensor N, Ambu A/S,
Ballerup Denmark). Skin preparation and electrode
placement were performed according to international
guidelines for sensor placement (Hermens et al. 2000).
sEMG signals were sampled at 1000 Hz during tendon
tap. The Achilles tendon was tapped with an instru-
mented hammer (ADInstruments, Australia). The sEMG
and hammer signal were collected using an ADI power
lab system (PowerLab 4/25, ADInstruments). The Tendon
Hammer contained a piezo-electric sensor within the head
to provide a momentary pulse when a surface is struck
with the hammer.
Analysis
Video and ultrasound
We pilot tested the procedures used in other studies
(Fletcher et al. 2010; Kay and Blazevich, 2009). During
this process, it became clear that we needed to modify
our procedures to determine tendon length. The previ-
ous studies fixed the ultrasound probe to the belly of the
medial gastrocnemius to image the attachment of the
distal portion of a muscle fascicle into the deep aponeur-
osis, where changes in tendon length were inferred from
displacement of the muscle fascicles, with the assump-
tion that the aponeurosis distal to the measurement site
remained a constant length, which we found was not the
case. To avoid the fixed length assumption and to image
the muscle-tendon junction more accurately, we manu-
ally held the ultrasound probe over the MG/AT MTJ
and used video to track the location of the ultrasound
markers on the probe (Figure 2b), which was digitized
using MaxTRAQ software (Figure 2c). This procedure
permitted adjustments to the ultrasound coordinates
due to any tilt of the probe to be made by multiplying
the vertical coordinates of the ultrasound image by
the digitized distance between the base of the probe
and the midpoint of the top of the probe (Figure 2b)
by the actual distance between those points. By doing
this we were able to precisely locate the muscle-
tendon junction in absolute space while making no
assumptions about the length of the aponeurosis. Reliabil-
ity of thee method was assessed by test-retest of 4 partici-
pants across 3 trials with a typical error measurement
Figure 2 Experimental set-up to determine the effect of AQUA
TITAN tape on triceps surae contractile function. Shown is (a)
positioning of the experimental tape covering the entire region of
the posterior lower limb (triceps surae), (b) the contrasting marker
(motion analysis) and ultrasound probe positioning and LED
synchronization marker, and (c) the ultrasound image of medial
gastrocnemius (MG)–Achilles junction (MTJ).
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(within-subject standard deviation) of tendon length
of 2.2%.
Tendon length and stiffness
Tendon length (TL) was calculated as the distance be-
tween the calcaneous marker and the MG/AT MJT in
absolute space. Based on the assumption that the effect
of the dorsiflexor muscles was minimal, Tendon Force
(TF) was estimated by dividing the torque about the
ankle joint, obtained from the Biodex with the torque
caused by the weight of the foot subtracted, by the mo-
ment arm of the Achilles tendon, d. The moment arm
was calculated using the equation
d¼⇀
xc−
⇀
xm
ðÞ
⇀
xmt −
⇀
xc
ðÞ
jj ⇀
xmt −
⇀
xc
ð Þjj
where ⇀
xiis a vector containing the position of the
markers in absolute space, with mt being the musculo-
tendinous junction, cbeing the calcaneus, and mbeing
the medial malleolus. Only the portion of each trial
where the tendon force was increasing was analyzed.
Tendon stiffness was calculated by fitting the following
equation to the estimated tendon length and force:
TF ¼F0þAeλTTL
;
where TF and TTL are the calculated tendon force and
tendon length measure respectively, and F
0
,Ae, and λ
was fit using the lsqnonlin function in MatLab. The vari-
able λwas used as a measure of the stiffness. The typical
error for λwas 16.8%.
To improve precision, only contractions with an R
2
>0.3
(large correlation; 697 of 960 contractions) were used in
the tendon stiffness analysis. A lower correlation was
deemed too variable for the TF/TL slope. The datasets
with R
2
> 0.5 reduced data points but did not affect the
AQUA TITAN tape outcome, but R
2
> 0.7 resulted in fail-
ure of the mixed model procedure to converge due to
insufficient data points. Estimates of tendon stiffness
previously used linear models (Lichtwark et al. 2007).
However, we and others (Lieber et al. 1991; Magid and
Law 1985; Pinto and Fung 1973; Winters 1990) observed
an exponential length-tension relationship for tendon dy-
namics during contraction, illustrated in Figure 3. Our ex-
ponential fit approach was therefore similar to Hill type
muscle models (Winters and Stark 1987).
Short latency reflex
The sEMG signal was amplified (BioAmp, ADInstru-
ments, Australia), low band-pass filtered (10–500 Hz)
and integrated in Chart for Windows (version7). The on-
set of reflex sEMG activity was defined as the time be-
tween the tendon tap (perturbation) and the first deflection
from baseline electrical activity and was determined by
visual inspection using a cursor on the display (Grey et al.
2002). The typical error was 4.8%.
Statistical analysis
The effect of treatment on outcomes was estimated with
mixed modelling (Proc Mixed, SAS Version 9.1; SAS In-
stitute, Cary, NC). All data were log-transformed before
modelling to reduce nonuniformity of error and to ex-
press outcomes and confidence limits (CL) as percent-
ages (Hopkins et al. 2009). Estimates for the effect of
treatment on tendon stiffness were derived from the
least-squares mean interaction of the model terms (fixed
effects) trial order, treatment, post-pre difference, and
contraction number (1 and 2); random effects were sub-
ject interacted with contraction number and treatment.
Estimates for ROM, short latency reflex, and peak iso-
kinetic torque were derived from a model but without
contraction or tap number due to trivial difference in
the magnitude of the intra-sample means, that is, the
value provided by the model was the average of the con-
tractions or tap number. Peak isokinetic torque was esti-
mated using the model approach as for ROM, but for
each of the 4 levels of angular torque and overall. Statis-
tical inference was by magnitude-based clinical inference
(Hopkins et al. 2009), with the between-subject stan-
dardized difference (modified Cohen’sd) used as the ref-
erence to effect size.
Results
AQUA TITAN tape led to a small increase in plantar-
flexor ROM (3.1% 95% CL: ±2.7%) (Figure 4b). A small
clear reduction in tendon stiffness (−16.5% ±8.1%) was
observed with placebo tape at 48-h post run, but this ef-
fect was trivialised with AQUA TITAN (−5.9% ±9.2%)
Figure 3 Example of a typical force-length relationship in the
Achilles tendon resulting from a maximal isometric contraction
in neutral anatomical position. The figure illustrates the
appropriateness of the exponential curve fit aligned to the raw data.
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(Figure 5 and Table 1). In contrast, the change in short
latency reflex time was negligible with placebo tape
(1.6%±3.8%)whencomparedtoanalmostcertain
large reduction with AQUA TITAN tape (−11.3%
±3.3%) (Figure 4a). The effect of AQUA TITAN tape
on peak isokinetic force was trivial (Table 1).
Discussion
In the current study, we utilised an isolated triceps surae
model to determine the effect of incorporation of AQUA
TITAN titanium micro particles to the flexible tape on
lower limb neural-musculotendinous function during
recovery from strenuous running. AQUA TITAN-tape
application caused a large reduction in short latency reflex
time and attenuated the reduction in Achilles tendon
stiffness seen with the non-treated control tape 48-h into
recovery. These observations suggest that the AQUA
TITAN-treated tape leads to faster neuromuscular re-
sponse to tendon load stimuli that is associated with res-
toration of tendon stiffness to the pre-loaded condition.
The increase in plantarflexion ROM was consistent in
magnitude to previous observations (Wadsworth et al.
2010) suggesting the effect of AQUA TITAN on ROM is
robust, but small. The effect of AQUA TITAN tape on
peak isokinetic force, however, was unaffected leaving the
pre-study hypothesis that increased contractility was a
mechanism for increased ROM unresolved.
These observations support the hypothesis that AQUA
TITAN-treated material applied to the skin better main-
tains contractile function of the muscle-tendon complex
following heavy loading. Stiff tendons are advantageous
for performing accurate and repetitive cyclical move-
ments (Alexander 2002; Lichtwark and Wilson 2005)
Figure 4 Effect of 48-h AQUA TITAN tape application following
high-intensity intermittent treadmill running on tendon-tap
stretch reflex response time and joint range of motion. Data are
(a) short latency reflex; (b) voluntary plantarflexion ROM. Data are
raw means. Variability bars are the between-subject SD.
Figure 5 Effect of AQUA TITAN tape on overall average Achilles
tendon stiffness measured during maximal isometric
contraction pre and post high-intensity intermittent treadmill
run. Data are the back log-transformed average mean stiffness of all
angles measure at maximal force. Variability bars are the
between-subject SD.
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and transmission of muscle shortening to joint move-
ment, whereas a highly compliant tendon may contrib-
ute to greater energy return in stretch-shortening
contractions (Alexander 2002). For tasks such as run-
ning, where the Achilles tendon does not undergo a
substantial pre-stretch (Lichtwark et al. 2007), it would
be expected that maintenance of tendon stiffness
would lead to less decrement in contractile-unit per-
formance with fatigue. Therefore, the new information
on reflex control of tendon stiffness may partly explain
improved running metabolic efficiency with AQUA
TITAN garments (Rowlands et al. 2013; Wadsworth
et al. 2010). As a point of reference to effect magni-
tude, small-moderate (standardized difference: 0.56 to
0.8) increases in tendon stiffness were observed in re-
sponse to prolonged periods (8–12 weeks) of isometric
training (Kubo et al. 2002, 2001). The attenuation in
the fatigue-induced stiffness response induced with
only 48-h tape intervention, is therefore, noteworthy.
The large reduction in short latency reflex suggests
that AQUA TITAN tape has a neurological effect on
muscular coordination. Korte (2008) reported that mouse
hippocampal pyramidal neurons mounted on a slide
under AQUA TITAN tape had lower resting-membrane
potential and dose-sensitive firing rates reducing the cap-
acity for long term potentiation induction. Since the short
latency reflex is dependent on the balance of excitatory
and inhibitory inputs from receptors and in turn modu-
lates the excitability of motor neurons (Hultborn et al.
1987), the present faster tendon-tap reflex suggests that
faster nerve conduction through a reflex arc might im-
prove the in vivo peripheral motor control. The peripheral
response may, via afferent feedback networks, also influ-
ence central motor centres increasing the potential for al-
terations in postural balance or cyclic tasks that utilize
acute feedback to improve contractile function or provide
musculoskeletal stability during movement (Ishikawa and
Komi 2007).
Table 1 Statistical summary of the effect of AQUATITAN tape applied during recovery from intermittent high-intensity
running on Achilles tendon stiffness, ankle joint range of motion during plantarflexion, and the short latency reflex,
relative to the pre-run baseline, and the post-treatment comparisons for peak torque during maximal isokinetic
contractions of the Triceps Surae
Outcome
1
Mean effect; ±95%CL(%)
2
Standardised
difference; ±95%CL
P-value Magnitude-based
inference
3
Achilles tendon stiffness
Placebo −16.5; ±8.1 −0.40; ±0.21 32E-5 Small very likely
AQUA TITAN −5.9; ±9.2 −0.14; ±0.23 0.23 Trivial possible
AQUA TITAN- Placebo −11.3; ±11.6 −0.28; ±0.31 0.09 Small possible
Plantarflexion range of motion
Placebo −1.6; ±1.9 −0.12; ±0.15 0.12 Trivial likely
AQUA TITAN 1.6; ±2.0 0.12; ±0.15 0.11 Trivial likely
AQUA TITAN- Placebo −3.1; ±2.7 −0.24; ±0.21 0.03 Small possible
Short latency reflex time
Placebo 1.6; ±3.8 0.20; ±0.48 0.42 Small possible
AQUA TITAN −11.3; ±3.3 −1.4; ±0.47 8E-9 Large almost certain
AQUA TITAN- Placebo 14.6; ±6.2 1.8; ±0.7 26E-7 Large almost certain
Peak torque during maximal isokinetic
contraction
30º∙s
-1
AQUA TITAN- Placebo 4.2; ±14.2 0.06; ±0.19 0.57 Likely trivial
60º∙s
-1
AQUA TITAN- Placebo 11.1; ±10.9 0.12; ±0.12 0.03 Likely trivial
90º∙s
-1
AQUA TITAN- Placebo −7.3; ±8.2 −0.08; ±0.09 0.09 Very likely trivial
120º∙s
-1
AQUA TITAN- Placebo −6.2; ±13.8 −0.07; ±0.15 0.41 Likely trivial
Overall AQUA TITAN- Placebo 0.08; ±7.7 0.001; ±0.08 0.98 Almost certainly trivial
1
Data are the difference in the post intermittent high-intensity run measure minus the pre run measure. For peak torque during maximal isokinetic contracti on,
only the post-pre difference in the AQUA TITAN minus Placebo contrasts is shown.
2
Add or subtract this value by the mean to obtain the upper and lower confidence limits.
3
Magnitude-based inferences about the true value for outcomes were qualified using a modification of the Cohen effect size classification system (trivial = 0.0–0.2,
small = 0.2–0.6, moderate = 0.6–1.2, large = 1.2–2.0, very large = 2.0–4.0, and extremely large >4.0). The threshold standardised difference considered substantial is
small. The thresholds for assigning qualitative terms to probability of a substantial effect were: <0.5%, almost certainly not; <5%, very unlikely; <25%, unlikely;
<75%, possible; >75%, likely; >95%, very likely; >99.5%, almost certain (Hopkins et al. 2009).
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In addition, reflex latency can modulate muscle-
tendon complex stiffness by activation of the spindle
during stretch associated with contraction (Cronin
et al. 2011; Kay and Blazevich 2009). Cronin et al.
(2011) used vibration to impair the triceps surae short
latency reflex resulting in greater ankle yield during
thesupportphaseofrunningandreducedforcetrans-
fer efficiency. Tendon stiffness itself could also affect
the contribution of afferent feedback in response to
rapid perturbations that elicit short latency reflexes
(Cronin et al. 2011). Moreover, feedback from group II
afferents in the muscle spindles and Golgi tendon or-
gans were suggested to make an important contribu-
tion to running mechanical efficiency (Mazzaro et al.
2005). Together these data suggest that faster short la-
tency reflex with AQUA TITAN may improve gait effi-
ciency independent of tissue adaptation and further
investigation into the effect on the peripheral nervous
system is warranted and the role this may have in
motor tasks and fine neural control of contractile
stiffness.
AQUA TITAN-treated material is shown to exert effects
on physiology even when not in direct contact with nerves,
this is supported by several lines of evidence in cells cul-
tured in plates above pico- to micrometer thickness of
titanium: with evidence of enhanced osteoblast differen-
tiation (Sugita et al. 2011), migration, proliferation, and
differentiation of myoblasts (Ishizaki et al. 2011) and al-
tered neuronal firing rate (Korte 2008). That the effects
of titanium are inhibited when cells are shielded with
aluminium wrapping and lead plates in both animal and
culture studies (Aoi et al. 2009; Korte 2008), indicates
that the influence of AQUA TITAN on neurons seems to be
mediated via some factor that can cross open space but
does not penetrate other metals, such as electromagnetic
waves. This is further supported in a recent in vivo study
where altered physiological stress responses were mea-
sured following five days sleeping in a room containing
titanium (Aoi et al. 2012). Further research is required
to determine the magnitude and clinical effects of
longer-term exposure to wearable garments treated with
AQUA TITAN, while information on dose response and
on the physical and physiological mechanisms will be
valuable in determining if there is a robust evidential
base for application.
Another possible mechanism for the changes observed
with AQUA TITAN is improved thermal conductivity.
Previously, participants reported increased thermal com-
fort with AQUA TITAN garments (Wadsworth et al.
2010). Titanium dioxide has a relatively moderate thermal
conductivity of 5.8 W·m
−1
·K
−1
(compared to 0.6 W·m
−1
·K
−1
for water, 440 W·m
−1
·K
−1
for silver, and 220 W·m
−1
·K
−1
for
aluminium). Thus, the titanium particles in AQUA TITAN
tape may act as an affecter for tissue thermoregulation.
Heat plays a major role in the function of physiological pro-
cesses: in hyperthermia, muscles are able to produce less
force (Rall and Woledge 1990), tendon stiffness decreases
(Ettema and Huijing 1994), and nerve performance is im-
paired (De Vrind et al. 1992). By maintaining a more con-
sistent temperature during contraction, altered material
thermal conductivity could explain the improvements in
motor reflex latency, ROM, and maintenance of tendon
stiffness reported here. Therefore, studies on the effect of
AQUA TITAN on skeletal muscle and tendon temperature
during contractile activity are warranted to examine the
thermal conductivity hypothesis.
Limitations
Our insight, attention to double-blinding, and resource
limitations when designing the current experiments was
not sufficient to consider including a non-taped condi-
tion within the crossover. In the review process, it was
brought to our attention that because of the potential for
taping to enhance proprioceptive acuity by increased stimu-
lation of the cutaneous mechanoreceptors (Feuerbach et al.
1994), a non-taped condition should be considered in fu-
ture research. A non-taped condition would permit quanti-
fication of the magnitude of the tape effect next to the
AQUA TITAN-tape mediated tendon tap response, al-
though masking a placebo effect could be difficult to re-
solve. A second limitation was our assumption that the
dorsiflexor moment was minimal and that the recorded
moment was equal to the moment from the dynamometer.
Magnusson et al. (2001) found there was minimal change
in calculated tendon force based on a correction for dorsi-
flexor coactivation during maximal plantarflexion. Given
that the study sought to compare AQUA TITAN-treated
tape against non-treated placebo tape, and that neither
tape covered the tibialis anterior, there was a priori no clear
reason to suspect greater tibialis anterior activation. Never-
theless, the possibility that AQUA TITAN-tape may affect
efferent motor nerve activity via a supraspinal mechanism
is worthy of further investigation.
With respect to the tendon moment arm, our calcula-
tions were based on the location of skin markers as
there was no imaging of the ankle joint during the
movement. Absence of imaging removed the possibility
of determination of the moments. Other researchers
(Fletcher et al. 2010; Kay and Blazevich, 2009) calculated
the moment arm as the ratio of tendon shortening to
angular displacement of the joint; however, this also re-
quires accurate measurements of the ankle angle, which
would have had to be determined by skin markers, and
therefore creating similar innate errors to our present
method. The ultrasound and recording systems were
triggered by the same source, which meant that the
starting point for subsequent analysis was in unison. The
camera was synchronized using the first frame in which
Hughes et al. SpringerPlus 2013, 2:653 Page 8 of 10
http://www.springerplus.com/content/2/1/653
a light appeared giving accuracy to within 1/30 of a second;
however, future studies should attempt increased temporal
synchronisation.
Conclusion
The application of AQUA TITAN-treated tape to the tri-
ceps surae complex during and following strenuous run-
ning decreased short latency reflex response time and
maintained Achilles tendon stiffness, relative to untreated
placebo tape. The inference from the short latency reflex
outcome suggests faster reflex motor control as the most
likely mechanism responsible for the tendon response,
which might improve musculotendinous performance.
These findings may explain, in part, faster restoration of
running economy reported with application of AQUA
TITAN-treated garments during recovery from strenuous
exercise. A greater understanding of the physical mechan-
ism of action of dermally-applied AQUA TITAN-treated
materials on the physiological processes influencing mus-
culotendinous recovery is required to provide further
evidence in support of the restoration hypothesis.
Competing interest
Funding assistance and the experimental tapes for the study was provided
by Phiten Co. Ltd., Kyoto, Japan. The study sponsors had no involvement in
the design, conduct of the study, nor manuscript preparation. David
Rowlands received speaking honoraria.
Authors’contributions
JH participated in the study design and coordination, carried out the
acquisition of data and drafted the manuscript. PF participated in the study
design carried out modelling of data and participated in manuscript drafting.
DG participated in the study design and assisted with drafting the
manuscript. DR conceived the study, participated in its design and
coordination, performed the statistical analysis and helped to draft the
manuscript. All authors read and approved the final manuscript.
Acknowledgement
Laboratory assistance from Michael Lewis, Linda Shailer and Wendy O’Brien.
Author details
1
Exercise and Sport Research Centre, University of Gloucestershire,
Gloucester, UK.
2
Rehabilitation Sciences, Griffith University, Gold Coast,
Queensland, Australia.
3
School of Sport and Exercise, Massey University,
Palmerston North, New Zealand.
4
School of Sport and Exercise, Massey
University Wellington, Wellington, New Zealand.
Received: 14 August 2013 Accepted: 28 November 2013
Published: 5 December 2013
References
Alexander RM (2002) Tendon elasticity and muscle function. Comp Biochem
Physiol Mol Int Physiol 133(4):1001–1011, doi: 10.1016/s1095-6433(02)00143-5
Aoi W, Takanami Y, Kawai Y, Otsuki T, Kawake T, Naito Y, Yoshikawa T (2009)
Relaxant effect of microtitan via regulation of autonomic nerve activity in
mice. Life Sci 85(9–10):408–411, doi: 10.1016/j.lfs.2009.07.007
Aoi W, Kamata T, Ishiura Y, Tomaru M, Satoh Y, Hitomi Y, Uchida K, Naito Y,
Yoshikawa T (2012) Titanium-treated surroundings attenuate psychological
stress associated with autonomic nerve regulation in office workers with
daily emotional stress. Physiol Behav 108:13–18, doi: 10.1016/j.
physbeh.2012.09.009
Arampatzis A, De Monte G, Karamanidis K, Morey-Klapsing G, Stafilidis S,
Brugg emann G-P ( 2006) Influence of the muscle–tendon unit’s mechanical
and morphological properties on running economy. J Exp Biol 209:3345–3357
Cronin NJ, Carty CP, Barrett RS (2011) Triceps surae short latency stretch reflexes
contribute to ankle stiffness regulation during human running. PLoS ONE 6
(8):e23917, doi: 10.1371/journal.pone.0023917
De Vrind H, Wondergem J, Haveman J (1992) Hyperthermia-induced damage to
rat sciatic nerve assessed in vivo with functional methods and with
electrophysiology. J Neurosci Methods 45(3):165–174
Drust B, Reilly T, Cable NT (2000) Physiological responses to laboratory-based
soccer-specific intermittent and continuous exercise. J Sports Sci 18
(11):885–892
Ettema GJC, Huijing PA (1994) Skeletal muscle stiffness in static and dynamic
contractions. J Biomechanics 27(11):1361–1368, doi: 10.1016/0021-9290(94)
90045-0
Feuerbach JW, Grabiner MD, Koh TJ, Weiker GG (1994) Effect of an ankle orthosis
and ankle ligament anesthesia on ankle joint proprioception. Am J Sports
Med 22(2):223–229
Fletcher J, Esau S, MacIntosh B (2010) Changes in tendon stiffness and running
economy in highly trained distance runners. Eur J Appl Physiol 110
(5):1037–1046, doi: 10.1007/s00421-010-1582-8
Fukashiro S, Komi PV, Järvinen M, Miyashita M (1995) In vivo achilles tendon
loading during jumping in humans. Eur J Appl Physiol 71(5):453–458, doi:
10.1007/bf00635880
Grey M, Larsen B, Sinkjær T (2002) A task dependent change in the medium
latency component of the soleus stretch reflex. Exp Brain Res 145(3):316–322,
doi: 10.1007/s00221-002-1109-6
Hermens HJ, Freriks B, Disselhorst-Klug C, Rau G (2000) Development of
recommendations for SEMG sensors and sensor placement procedures.
J Electromyogr Kinesiol 10(5):361–374, doi: 10.1016/s1050-6411(00)00027-4
Hirata Y, Ueda Y, Takase H, Suzuki K (2004) High functional water containing
titanium and method and apparatus for producing the same. New Zealand
Patent 522431
Hof AL, Van Zandwijk JP, Bobbert MF (2002) Mechanics of human triceps surae
muscle in walking, running and jumping. Acta Physiol Scand 174(1):17–30,
doi: 10.1046/j.1365-201x.2002.00917.x
Hopkins WG, Marshall SW, Batterham AM, Hanin J (2009) Progressive statistics for
studies in sports medicine and exercise science. Med Sci Sports Exerc 41
(1):3–13
Hultborn H, Meunier S, Pierrot-Deseilligny E, Shindo M (1987) Changes in pre-
synaptic inhibition of Ia fibres at the onset of voluntary contraction in man.
J Physiol 389(1):757–772
Hunter I, Smith G (2007) Preferred and optimal stride frequency, stiffness and
economy: changes with fatigue during a 1-h high-intensity run. Eur J Appl
Physiol 100(6):653–661, doi: 10.1007/s00421-007-0456-1
Ishikawa M, Komi PV (2007) The role of the stretch reflex in the gastrocnemius
muscle during human locomotion at various speeds. J Appl Physiol 103
(3):1030–1036, doi: 10.1152/japplphysiol.00277.2007
Ishizaki K, Sugita Y, Iwasa F, Minamikawa H, Ueno T, Yamada M, Suzuki T, Ogawa
T (2011) Nanometer-thin TiO
2
enhances skeletal muscle cell phenotype and
behavior. Int J Nanomed 6:2191–2203
Kay AD, Blazevich AJ (2009) Isometric contractions reduce plantar flexor moment,
Achilles tendon stiffness, and neuromuscular activity but remove the
subsequent effects of stretch. J Appl Physiol 107(4):1181–1189, doi: 10.1152/
japplphysiol.00281.2009
Korte M (2008) Influence of Aquatitan Tape on nerve cells of the central nervous
system. J Clin Biochem Nutr 43:1–4
Kubo K, Kanehisa H, Ito M, Fukunaga T (2001) Effects of isometric training on the
elasticity of human tendon structures in vivo. J Appl Physiol 91(1):26–32
Kubo K, Kanehisa H, Fukunaga T (2002) Effects of resistance and stretching
training programmes on the viscoelastic properties of human tendon
structures in vivo. J Physiol 538(1):219–226
Lichtwark GA, Wilson AM (2005) Effects of series elasticity and activation
conditions on muscle power output and efficiency. J Exp Biol 208(15):2845–2853,
doi: 10.1242/jeb.01710
Lichtwark GA, Wilson AM (2007) Is Achilles tendon compliance optimised for
maximum muscle efficiency during locomotion? J Biomech 40(8):1768–1775,
doi:10.1016/j.jbiomech.2006.07.025
Lichtwark GA, Bougoulias K, Wilson AM (2007) Muscle fascicle and series elastic
element length changes along the length of the human gastrocnemius
during walking and running. J Biomech 40(1):157–164
Lieber RL, Leonard ME, Brown CG, Trestik CL (1991) Frog semitendinosis tendon
load-strain and stress–strain properties during passive loading. Am J Physiol
Cell Physiol 261(1):C86–C92
Hughes et al. SpringerPlus 2013, 2:653 Page 9 of 10
http://www.springerplus.com/content/2/1/653
Magid A, Law DJ (1985) Myofibrils bear most of the resting tension in frog
skeletal muscle. Science 230(4731):1280–1282
Magnusson SP, Aagaard P, Dyhre-Poulsen P, Kjaer M (2001) Load–displacement
properties of the human triceps surae aponeurosis in vivo. J Physiol 531
(1):277–288
Mazzaro N, Grey MJ, Sinkjær T (2005) Contribution of afferent feedback to the
soleus muscle activity during human locomotion. J Neurophysiol 93
(1):167–177, doi: 10.1152/jn.00283.2004
Pinto JG, Fung YC (1973) Mechanical properties of the heart muscle in the
passive state. J Biomech 6(6):597–616, doi: 10.1016/0021-9290(73)90017-1
Rahnama N, Lees A, Reilly T (2006) Ele ctromyography of sel ected lower-limb
muscles fatigued by exercise at the intensity of soccer match-play. J Electromyo
and Kinesiol 16(3):257–263, doi: 10.1016/j.jelekin.2005.07.011
Rall JA, Woledge RC (1990) Influence of temperature on mechanics and
energetics of muscle contraction. Am J Physiol Reg Int Comp Physiol
259(2):R197–R203
Rowlands DS, Graham DF, Fink PW, Wadsworth DP, Hughes JD (2013) Effect of
whole-body microtitanium-treated garments on metabolic cost of exercise
following strenuous hill running. J Sci Med Sport, doi: 10.1016/j.
jsams.2013.03.003
Sugita Y, Ishizaki K, Iwasa F, Ueno T, Minamikawa H, Yamada M, Suzuki T, Ogawa
T (2011) Effects of pico-to-nanometer-thin TiO2 coating on the biological
properties of microroughened titanium. Biomaterials 32(33):8374–8384,
doi: 10.1016/j.biomaterials.2011.07.077
Wadsworth DP, Walmsley A, Rowlands DS (2010) Aquatitan garments extend
joint range of motion without effect on run performance. Med Sci Sports
Exerc 42(12):2273–2281
Winters J (1990) Hill-based muscle models: a systems engineering perspective to
multiple muscle systems. Springer-Verlag, New York
Winters J, Stark L (1987) Muscle models: what is gained and what is lost by
varying model complexity. Biol Cybernetics 55(6):403–420, doi: 10.1007/
bf00318375
doi:10.1186/2193-1801-2-653
Cite this article as: Hughes et al.:Effect of microtitanium impregnated
tape on the recovery of triceps surae musculotendinous function
following strenuous running. SpringerPlus 2013 2:653.
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