Available via license: CC BY-NC-ND 4.0
Content may be subject to copyright.
Immediate effects of ultrasound therapy on pain and plantar pressure
in individuals with subacute ankle sprains: a randomized controlled trial
DOI: https://doi.org/10.5114/pq/169211
Thongchai Suksri1,2 , Chitanongk Gaogasigam1 , Sujitra Boonyong1
1 Human Movement Performance Enhancement Research Unit, Department of Physical Therapy, Faculty of Allied Health
Sciences, Chulalongkorn University, Bangkok, Thailand
2 Department of Physical Therapy, Medical Division of Armed Forces Academies Preparatory School, Nakhon Nayok,
Thailand
Abstract
Introduction. Despite the fact that ultrasound (US) therapy is not advised for acute ankle sprains, its therapeutic effects may be
beneficial for other stages of ankle sprains, such as a subacute ankle sprain. There is, however, a lack of evidence regarding the
effects of US on pain relief and functional improvement in subacute ankle sprains. Therefore, this study aimed to determine the
immediate effects of US on pain and plantar pressure in individuals with unilateral subacute ankle sprains.
Methods. Fifty-four participants with unilateral subacute ankle sprains (aged 16–55 years) were recruited and randomly allo-
cated into a treatment group (n = 27) and a control group (n = 27). The treatment and control groups received a single interven-
tion session of US and an ineffectual US, respectively. Pain intensity during weight-bearing and static and dynamic plantar
pressures were assessed before and after receiving the intervention.
Results. In both groups, pain intensity was statistically reduced (p < 0.05) and clinically relevant. Although the maximum plantar
pressure in the hindfoot during static conditions was statistically higher in the control group (p = 0.024), the values were still
lower than MDC95.
Conclusions. A single treatment of US could clinically reduce pain, but it had no effect on altering plantar pressure in individuals
with unilateral subacute ankle sprains.
Key words: ankle, sprains, ultrasound, weight-bearing, pain
Physiotherapy Quarterly (ISSN 2544-4395)
2024, 32(3), 15–20
Correspondence address: Sujitra Boonyong, Department of Physical Therapy, Faculty of Allied Health Sciences, Chulalongkorn University,
154 Rama 1 Road, Wangmai, Pathumwan, Bangkok 10330, Thailand, e-mail: sujitra.b@chula.ac.th; https://orcid.org/0000-0001-9462-2131
Received: 03.12.2022
Accepted: 04.07.2023
Citation: Suksri T, Gaogasigam C, Boonyong S. Immediate effects of ultrasound therapy on pain and plantar pressure in individuals with
subacute ankle sprains: a randomized controlled trial. Physiother Quart. 2024;32(3):15–20; doi: https://doi.org/10.5114/pq/169211.
original paper
© Wroclaw University of Health and Sport Sciences
Introduction
Lateral ankle sprains are the most frequent type of ankle
injury experienced during sports and exercise (85% of all
cases), which commonly involve an injury to the anterior
tal ofibular ligament (ATFL; about 70% of cases) [1]. Individu-
als with ankle sprains return to daily life activity in an average
of 28 to 33 days after injury. Unfortunately, more than 40% of
improperly healed ankle sprains progress to chronic ankle
dysfunctions, which cause pain during weight-bearing activity
on the affected foot, recurrent swelling, and recurrent injuries
[2], thus impacting daily life activities [3]. It is critical to pre-
vent this progression.
To avoid the development of chronic ankle dysfunction,
appropriate interventions should be implemented to elimi-
nate the symptoms during the subacute phase [4]. In this
phase, soft tissue repair takes place as fibroblasts begin to be
synthesized at the affected area and produce collagen. This
period usually appears within 4 days after injury and tends to
last for 10 to 14 days [5].
Due to its therapeutic effects, one physical therapy mo-
dality frequently used to treat ankle sprain is ultrasound (US)
therapy [6, 7]. The thermal effects of US can enhance blood
flow and the extensibility of tissues while minimizing pain
[6, 8]. Most studies reported pain improvement after several
sessions of thermal US [9]. However, a single session of ther-
mal US would reduce pain in musculoskeletal conditions as
it would affect nociceptive information [10]. In addition, the
non-thermal effects can promote intracellular calcium, cell
membrane permeability, and protein synthesis [11–14]. More-
over, US has direct effects on the viscoelastic properties of
collagen [15]. A recent systematic review concluded that US
does not appear to help with pain and swelling or standing on
the affected foot in acute ankle sprains, thus, it is not recom-
mended for the treatment of acute ankle sprains [9]. Further-
more, theliteraturelacks detailed information on US param-
eters. To our knowledge, however, no study has focused on the
effectiveness of US on pain relief in subacute ankle sprains.
Meanwhile, there is a lack of evidence showing whether
US can relieve pain as well as improve weight-bearing in in-
dividuals with subacute ankle sprains. Therefore, this study
aimed to investigate the immediate effects of a single US
treatment in individuals with unilateral subacute ankle sprains.
US parameters in this study were set primarily based on the
thermal effect. We hypothesized that a single applied US
treatment with a specific parameter setting for pain relief
could reduce pain and improve weight bearing in individuals
with unilateral subacute ankle sprains.
Subjects and methods
Participants
Participants were recruited from local physical therapy
clinics in the provinces of Nakon Nayok and Pathum Thani,
Thailand, between April 2020 and December 2020.
Participants diagnosed with unilateral lateral ankle sprains
(grades 1–2) by a physician at least 4 days and up to 14 days
T. Suksri, C. Gaogasigam, S. Boonyong
Immediate effects of ultrasound therapy on pain and plantar pressure in individuals with subacute ankle sprains
16
Physiother Quart 2024, 32(3)
after injury were recruited for this study. All participants met
the inclusion criteria, including having pain during weight-
bearing for at least 30 mm of a 100-mm visual analog scale
(VAS), and the ability to communicate and use a VAS. Ex-
clusion criteria were redness and warmth at the area of the
ankle sprain, numbness of the lower extremity, vestibular prob-
lems confirmed by medical history, and having any contrain-
dications to US.
The sample size was calculated using G*power version
3.1.9.4 with a significance level of 0.05, desired power of
0.80, and effect size of 0.80. The estimation of effect size was
based on previous studies related to musculoskeletal pain
[16, 17]. The estimated required sample size was calculated
to be at least 52 participants. Therefore, the sample size was
at least 26 per group. However, we decided to protect against
drop out of participants in the instance they have adverse ef-
fects from US. Therefore, the sample size was included to be
54 and separated into each group to be 27 per group.
Procedure
We conducted a double-blind randomized, controlled trial.
The participants were unaware of the group assignment. In-
vestigator 1 recruited participants and performed treatment
sessions. Investigator 2 evaluated outcome measurements
at baseline and after treatment and was unaware of group
assignments. In addition, the outcome assessments and treat-
ment sessions were conducted in a separate room.
Fifty-four participants were divided into 2 groups, includ-
ing a treatment group and a control group by investigator 1,
following a stratified randomization procedure based on the
incidence of the ankle sprain found in adolescents and adults
[18]. The stratified random sampling methods were performed
to balance gender and age between the groups. Participants
were randomly allocated into the treatment and control groups
by using opaque sealed envelopes.
Outcomes measures
Baseline evaluation included demographic and clinical
characteristic data, including age, gender, height, weight, body
mass index, duration of injury, side of injury, the severity of the
injury, and pain intensity during weight-bearing (see Table 1).
All participants were assessed for outcome measures,
including pain intensity during weight-bearing, static and dy-
namic plantar pressure distribution before and after interven-
tion. Static and dynamic maximum plantar pressure (kPa)
measurements were analyzed for the three regions, includ-
ing the forefoot, midfoot, and hindfoot. These outcome meas-
urements were assessed by investigator 2, who was trained
and had high reliability in pain intensity measurements (ICC(3, 1)
= 0.99) and good to high test-retest reliability of maximum
plantar pressures (ICC(2,1) were 0.72, 0.85, and 0.85 for the
forefoot, midfoot, and hindfoot, respectively). The test-retest
minimal detectable change with 95% confidence (MDC95) for
pain was 5.04 mm [19], and MDC95 for maximum plantar pres-
sures were 15.40, 19.22, and 45.24 kPa for forefoot, midfoot,
and hindfoot, respectively.
To measure the outcomes, we asked participants to step
down on the affected side once. Pain intensity during weight-
bearing was measured using 100-mm VAS. Then, static and
dynamic plantar pressure distributions were measured using
a plantar pressure platform system (DIERS International GmbH,
Germany) with a sampling rate of 200 Hz. To measure static
plantar pressure, participants were instructed to stand with
their feet apart on the platform. Data were recorded for 15 sec-
onds. Then, the dynamic plantar pressure of the affected side
was measured by having the participants stand at a distance,
after which they would take two steps before striking the plat-
form with the affected side. Participants were allowed 2–3 tri-
als to familiarize themselves with the protocol. Data for one trial
of each static and dynamic task was used for data analysis.
In addition, participants were allowed to take a rest at their
request.
Interventions
For intervention sessions, participants maintained a supine
position until the end of the session. Investigator 1 used a So-
nopuls 490 US device (Enraf-Nonius, Lisburn, UK) equipped
with a US transducer with an effective radiation area of 5.0 cm2
and a beam non-uniform ratio of 1:6. The US transducer was
calibrated before applying it to the participants. The treatment
area was estimated at approximately 10 cm2 and marked by
using a bendable wire circle and pen. The US was applied to
the painful area on the lateral aspect of the ankle.
In the treatment group, participants received US accord-
ing to the therapeutic purpose (thermal effect) [20]. US treat-
ment intensity was set at 0.25 W/cm2 with a duty cycle of 100%,
a spatial average-temporal average (SATA) of 0.25 W/cm2,
and a frequency of 3 MHz. A circular stroke technique was
applied and the treatment time was set for 6 minutes [7, 21].
In the control group, participants received the ineffectual US,
which was set at minimal energy. US treatment intensity was
set at 0.05 W/cm2 with a duty cycle of 5%, SATA of 0.0025
W/cm2, and the same frequency, treatment duration, and tech-
niques used in the treatment group. After finishing the inter-
vention sessions, participants were reassessed for all out-
come measures (Figure 1).
Statistical analysis
Statistical analysis was performed using SPSS version 22
(IBM). The Shapiro–Wilk test was used to test the normality of
data. All data were normally distributed. Independent t-tests
were used to determine the differences between the treat-
ment and control groups. Paired t-tests were used to deter-
mine the differences before and after the intervention within
each group. Statistical significance was set at p < 0.05.
Figure 1. Flow diagram for the study
T. Suksri, C. Gaogasigam, S. Boonyong
Immediate effects of ultrasound therapy on pain and plantar pressure in individuals with subacute ankle sprains
17
Physiother Quart 2024, 32(3)
Table 2. Within and between-group comparisons of pain intensity during weight-bearing in individuals with unilateral subacute lateral
ankle sprains for the treatment and control groups
Variables Baseline
mean ± SD
After treatment
Bangkok, Thailand
Mean difference
(95% CI) p†Effect
size‡p‡Effect
size‡
VAS scores (mm)
treatment group
(n = 27) 49.54 ± 15.37 28.78 ± 18.77 19.28
(14.75, 26.77) 0.000* 1.10
0.949 0.462
control group
(n = 27) 44.85 ± 14.11 32.30 ± 21.60 12.56
(8.25, 16.89) 0.000* 1.15
VAS – visual analog scale
* significant differences (p < 0.05)
† paired t-test was compared between baseline and after treatment for each treatment and control group
‡ independent t-test comparing the mean difference between treatment and control groups after the treatment
Table 1. Demographic and clinical characteristic data
of the treatment and control groups (values are mean ± SD
unless otherwise indicated)
Variables Treatment group
(n = 27)
Control group
(n = 27) p†
Gender, n (%)
male 22 (82) 22 (82) –
female 5 (18) 5 (18) –
Age (years) 26.04 ± 11.03 26.07 ± 10.26 0.990
Height (cm) 169.44 ± 7.85 170.04 ± 8.98 0.797
Weight kg) 66.31 ± 9.70 70.04 ± 13.20 0.242
BMI (kg/m2) 23.05 ± 2.65 24.29 ± 4.79 0.243
Duration of injury (days) 7.00 ± 3.70 6.33 ± 2.87 0.463
Side of injury (n; %)
right 16 (59.30) 14 (51.90) –
left 11 (40.70) 13 (48.10) –
Severity of the injury, n (%)
grade 1 5 (18.50) 6 (22.20) –
grade 2 22 (81.50) 21 (77.80) –
VAS scores (mm)
weight-bearing 49.54 ± 15.37 44.85 ± 14.11 0.249
BMI – body mass index, VAS – visual analog scale
† Independent t-test compares the mean difference between
treatment and control groups
Results
There were no significant differences in characteristics
between the treatment and control groups (Table 1).
Before receiving an intervention, there were no signifi-
cant differences in pain intensity during weight-bearing and
static and dynamic maximum plantar pressures between
the treatment and control groups (p > 0.05). After receiving an
intervention, pain intensity significantly decreased in both
groups (p < 0.01). However, this decreased pain intensity did
not differ significantly between groups (p > 0.05; Table 2).
For static plantar pressure measurements, only the con-
trol group displayed an increased maximum plantar pres-
sure in the hindfoot after interventions (p = 0.024). However,
there was no significant difference between the groups (p >
0.05, Table 3).
For dynamic plantar pressure measurements, no variables
showed significant differences between groups or within each
group (p > 0.05, Table 4).
Discussion
We aimed to investigate the immediate effect of single-
treatment US in individuals with unilateral subacute ankle
sprains. We found statistically significant improvement in
pain intensity in both treatment and control groups. However,
weight-bearing in terms of plantar pressure did not show any
obvious improvement.
Both groups reported significant pain reduction during
weight-bearing after receiving an intervention. The mean pain
intensity after treatment decreased by 19.28 mm and 12.56 mm
in the treatment and control groups, respectively, with large
effect sizes of 1.10 and 1.15. In addition, the pain intensity of
both groups met the minimal detectable change of 5.04 mm,
which was reported in a previous study [19]. Even though,
VAS showed variability of pain intensity, pain reduction in
both groups was sufficient to allow a meaningful effect that
indicated clinically significant changes, confirming the anal-
gesic effect.
The US parameters used were set according to the ther-
apeutic purpose, which was the thermal effect. Appropriate
US parameter settings can significantly affect treatment out-
comes [20]. Besides parameter setting, the types of lesions
treated (e.g., muscle, tendon, or ligament) should be consid-
ered [20]. The rate of temperature increase in a participant’s
tendons was greater than that in their muscles, as the ten-
dons showed poor blood circulation [22–24]. Furthermore,
a recent systematic evaluation of US therapy in acute ankle
sprains discovered a non-identified objective of US parameter
setting as well as a risk of bias due to a lack of blinding of care
providers, patients, or outcome assessments [9]. Therefore,
considering US parameters, lesion type, and risk of bias can
further improve the measured outcomes.
Previous studies reported that the thermal effect of US
could reduce pain by increasing local blood circulation [6, 25],
the pain threshold, and enzymatic activity, as well as accel-
erate the metabolic rate, change nerve conduction velocities,
increase the extensibility of collagen fibers [26, 27], and de-
crease nitric oxide synthesis [28]. US-induced antinocicep-
tion involved the attenuation of the inflammatory response,
as seen by lower levels of spinal proinflammatory cytokines, as
well as changes in neuronal excitability, membrane perme-
ability, and immune cell activity in the joints [10]. For a single
ses sion of US treatment, the short-term antinociception caused
by US was associated with changes in nerve conduction ve-
locity, cell membrane permeability, and possibly cell excita-
bility. These changes would last for one hour [10]. Thus, pain
T. Suksri, C. Gaogasigam, S. Boonyong
Immediate effects of ultrasound therapy on pain and plantar pressure in individuals with subacute ankle sprains
18
Physiother Quart 2024, 32(3)
reduction after a single session of US could not be maintained
over time. Although US has been demonstrated to promote
inflammation and is not suggested for application in the in-
flammatory phase [9], it has been shown to be beneficial dur-
ing the proliferative phase. It stimulates fibroblasts, endothe-
lial cells, and myofibroblasts [6]. This study found that thermal
US has an advantageous effect on pain relief in subacute
ankle sprains. As a result, the biophysical properties of ther-
mal US after the acute period would be favorable to ligament
damage. Good outcomes for US therapy have been reported
in patients with epicondylitis [29], carpal tunnel syndrome [30],
calcific tendinitis of the shoulder [31], and chronic varicose
ulcers [32].
Even though our study found a reduction in pain intensity
in the control group, it was not influenced by thermal US be-
cause the settings were set at 0.0025 W/cm2 with a duty cycle
of 5% and frequency of 3 MHz, resulting in a minimal energy
of 0.45 J/cm2. However, this dose was unable to deliver a ther-
apeutic effect of thermal US as it has been shown to have
a therapeutic effect at energies ranging from 30–180 J/cm2
[21]. The reduction of pain intensity in this group could be
explained by the placebo effect. Previous studies have re-
ported that control groups can demonstrate effectiveness
equal to or superior to treatment groups in various areas, such
as knee osteoarthritis [16], delayed-onset muscle soreness
[33], and plantar fasciitis [17]. The physiological mechanisms
Table 4. Within and between-group comparisons of maximum plantar pressure (kPa) at the forefoot, midfoot, and hindfoot
under dynamic conditions in treatment and control groups
Variable Baseline
mean ± SD
After treatment
mean ± SD
Mean difference
(95% CI) p†Effect
size†p‡Effect
size‡
Forefoot maximum plantar pressure (kPa)
treatment group
(n = 27) 101.03 ± 35.13 105.21 ± 32.66 4.18
(–4.76, 13.12) 0.345 0.384
0.291 0.064
control group
(n = 27) 107.35 ± 31.41 105.76 ± 28.83 –1.60
(–8.23, 5.04) 0.625 0.155
Midfoot maximum plantar pressure (kPa)
treatment group
(n = 27) 65.14 ± 25.15 62.95 ± 22.05 –2.19
(–10.50, 6.13) 0.593 0.115
0.161 0.302
control group
(n = 27) 65.93 ± 32.25 70.96 ± 31.55 5.03
(–1.30, 11.36) 0.114 0.362
Hindfoot maximum plantar pressure (kPa)
treatment group
(n = 27) 137.02 ± 53.58 140.80 ± 42.98 3.78
(–10.96, 18.52) 0.602 0.271
0.934 0.065
control group
(n = 27) 153.71 ± 41.47 156.78 ± 42.00 3.07
(–6.47, 12.62) 0.514 0.461
† paired t-test comparing baseline and after treatment within each treatment and control group
‡ independent t-test comparing mean differences between treatment and control groups after treatment
Table 3. Within and between-group comparisons for maximum plantar pressure (kPa) at the forefoot, midfoot, and hindfoot
under static conditions in the treatment and control groups
Variable Baseline
mean ± SD
After treatment
mean ± SD
Mean difference
(95% CI) p†Effect
size†p‡Effect
size‡
Forefoot maximum plantar pressure (kPa)
treatment group
(n = 27) 46.40 ± 16.32 50.10 ± 17.24 3.63
(–0.11, 7.36) 0.056 0.384
0.407 0.064
control group
(n = 27) 51.10 ± 17.31 52.57 ± 17.76 1.47
(–2.29, 5.23) 0.428 0.155
Midfoot maximum plantar pressure (kPa)
treatment group
(n = 27) 34.7 ± 13.45 35.83 ± 11.83 1.07
(–2.60, 4.75) 0.554 0.115
0.277 0.302
control group
(n = 27) 34.20 ± 19.71 38.43 ± 20.72 4.23
(–0.39, 8.85) 0.071 0.362
Hindfoot maximum plantar pressure (kPa)
treatment group
(n = 27) 92.52 ± 36.13 97.45 ± 33.33 4.93
(–2.27, 12.12) 0.171 0.271
0.452 0.065
control group
(n = 27) 86.57 ± 37.30 95.34 ± 34.10 8.77
(1.25, 16.29) 0.024* 0.461
* significant difference (p < 0.05)
† paired t-test is compared between baseline and after treatment in each treatment and control group
‡ independent t-test compared the mean differences between treatment and control groups after treatment
T. Suksri, C. Gaogasigam, S. Boonyong
Immediate effects of ultrasound therapy on pain and plantar pressure in individuals with subacute ankle sprains
19
Physiother Quart 2024, 32(3)
of the placebo effect depend on the physical and psychologi-
cal factors of the individuals. A participant’s positive expec-
tations could activate the endogenous opioid system, which
can affect pain relief via analgesic mechanisms [34, 35]. The
opioid-driven response is a part of placebo analgesia stimu-
lated by a descending pain modulation pathway involving the
rostral anterior cingulate cortex, orbitofrontal cortex, periaq-
ueductal grey matter, pons, and medulla [35]. These pathways
use opioids to increase inhibition at the dorsal horn of the spi-
nal cord. Consequently, they can reduce the number of noci-
ceptive signals reaching the brain.
In addition, moving US transducers over the area of treat-
ment may act as a local massage, which induces tactile an-
algesia and increases lymphatic blood flow and drainage in
both groups. Tactile analgesia can be explained by the gate
control theory [36]. The nerve impulses from mechanorecep-
tor stimulation by moving the transducer along the afferent
nerves block impulses from pain fibers at the dorsal horn of
the spinal cord. Then, pain information cannot be transmitted
up to the higher centers [37]. However, pain reduction by the
gate control theory has immediate effects of less than one
hour [38, 39].
Even though maximum plantar pressure in the hindfoot
was increased by 8.77 kPa in the control group, the changes
in maximum pressure did not meet the MDC95 value of 45.24
kPa. The use of a single US treatment only slightly decreased
the intensity of pain during weight-bearing, and plantar pres-
sure parameters changed inconclusively. Therefore, the ap-
plication of US in individuals with unilateral subacute lateral
ankle sprains may need to be conducted with more than
a single treatment session to yield improved functional activity.
Limitations
The limitation of the study included objective measure-
ments of pain intensity such as PPTs were not collected. More-
over, this study did not assess swelling, foot types (e.g., flat
foot, high arch), and the dominant limb of participants that
could affect plantar pressure measurements. Furthermore,
the frequency, types, and duration of regular exercise, as well
as occupational activities that could be associated with pain
and weight-bearing were not investigated in this study. There-
fore, further studies with PPT, swelling measurements, and
identifying the types of foot, dominant limb, and routine physi-
cal activity should be conducted. In addition, the full US treat-
ment program should be done with after-treatment follow-up.
Conclusions
In this study, a single US treatment demonstrated an im-
mediate effect on pain, but no improvement in plantar pres-
sure outcomes. A complete program of US treatment should
be investigated further to determine whether additional treat-
ment sessions would influence weight-bearing and improve
functional ability.
Acknowledgments
This study was supported by a Scholarship from the Grad-
uate School of Chulalongkorn University to commemorate
the 72nd anniversary of his Majesty King Bhumibol Aduladej
Fund and 90th Anniversary Chulalongkorn University Fund
(Ratchadaphiseksomphot Endowment Fund) (No. GCUGR-
1125632123M).
Ethical approval
The research related to human use has complied with all
relevant national regulations and institutional policies, has
followed the tenets of the Declaration of Helsinki, and has
been approved by the Research Ethics Review Committee for
Research Involving Human Research Participants, Group I,
Chulalongkorn, Thailand (approval No.: COA No.079/2020)
and were registered at ThaiClinicalTrials.org (TCTR registra-
tion No. TCTR20200423002).
Informed consent
Informed consent was obtained from all individuals in-
cluded in this study.
Disclosure statement
No author has any financial interest or received any finan-
cial benefit from this research.
Conflicts of interest
The authors state no conflicts of interest.
Funding
This research received no external funding.
References
[1] Ferran NA, Maffulli N. Epidemiology of sprains of the lat-
eral ankle ligament complex. Foot Ankle Clin. 2006;
11(3):659–62; doi: 10.1016/j.fcl.2006.07.002.
[2] Gerber JP, Williams GN, Scoville CR, Arciero RA, Tay-
lor DC. Persistent disability associated with ankle sprains:
a prospective examination of an athletic population. Foot
Ankle Int. 1998;19(10):653–60; doi: 10.1177/1071100
79801901002.
[3] Konradsen L, Bech L, Ehrenbjerg M, Nickelsen T. Seven
years follow-up after ankle inversion trauma. Scand J
Med Sci Sports. 2002;12(3):129–35; doi: 10.1034/j.16
00-0838.2002.02104.x.
[4] Miklovic TM, Donovan L, Protzuk OA, Kang MS, Feger MA .
Acute lateral ankle sprain to chronic ankle instability:
a pathway of dysfunction. Phys Sportsmed. 2018;46(1):
116–22; doi: 10.1080/00913847.2018.1409604.
[5] Weerasekara RM, Tennakoon SU, Suraweera HJ. Con-
trast therapy and heat therapy in subacute stage of
grade I and II lateral ankle sprains. Foot Ankle Spec.
2016;9(4):307–23; doi: 10.1177/1938640016640885.
[6] Watson T, Young SR. Therapeutic ultrasound. In: Wat-
son T (ed.) Electrotherapy. Evidence Based Practice. 12th
ed. Warsaw: Churchill Livingstone; 2008, pp. 179–200.
[7] Zammit E, Herrington L. Ultrasound therapy in the man-
agement of acute lateral ligament sprains of the ankle
joint. Phys Ther Sport. 2005;6(3):116–21; doi: 10.1016/
j.ptsp.2005.05.002.
[8] Rose S, Draper DO, Schulthies SS, Durrant E. The
stretching window part two: rate of thermal decay in
deep muscle following 1-MHz ultrasound. J Athl Train.
1996;31(2):139–43.
[9] van den Bekerom MP J, van der Windt DAWM, ter Riet G,
van der Heijden GJ, Bouter LM. Therapeutic ultrasound
for acute ankle sprains. Cochrane Database Syst Rev.
2011;2011(6): CD001250.
[10] Malta I, Moraes T, Elisei L, Novaes R, Galdino G. Inves-
tigation of the effects of therapeutic ultrasound or pho-
tobiomodulation and the role of spinal glial cells in oste-
oarthritis-induced nociception in mice. Lasers Med Sci.
2022;37(3):1687–98; doi: 10.1007/s10103-021-03418-7.
[11] Yadollahpour A, Rashidi S. A review of mechanism of
actions of ultrasound waves for treatment of soft tis-
sue injuries. Int J Green Pharm. 2017;11(1):13–20.
[12] Merrick MA, Mihalyov MR, Roethemeier JL, Cordova ML,
Ingersoll CD. A comparison of intramuscular tempera-
T. Suksri, C. Gaogasigam, S. Boonyong
Immediate effects of ultrasound therapy on pain and plantar pressure in individuals with subacute ankle sprains
20
Physiother Quart 2024, 32(3)
Copyright: © 2024 Wroclaw University of Health and Sport Sciences. This is an Open Access journal distributed under the terms of the Creative
Commons Attribution-NonCommercial-NoDerivs (CC BY-NC-ND) (https://creativecommons.org/licenses/by-nc-nd/4.0/legalcode), allowing
third parties to download and share its works but not commercially purposes or to create derivative works.
tures during ultrasound treatments with coupling gel
or gel pads. J Orthop Sports Phys Ther. 2002;32(5):216–
20; doi: 10.2519/jospt.2002.32.5.216.
[13] Draper DO, Mahaffey C, Kaiser D, Eggett D, Jarmin J.
Thermal ultrasound decreases tissue stiffness of trig-
ger points in upper trapezius muscles. Physiother Theory
Pract. 2010;26(3):167–72; doi: 10.3109/09593980903
423079.
[14] De Deyne PG, Kirsch-Volders M. In vitro effects of thera-
peutic ultrasound on the nucleus of human fibroblasts.
Phys Ther. 1995;75(7):629–34; doi: 10.1093/ptj/75.7.629.
[15] Sparrow KJ, Finucane SD, Owen JR, Wayne JS. The
effects of low-intensity ultrasound on medial collateral
ligament healing in the rabbit model. Am J Sports Med.
2005;33(7):1048–56; doi: 10.1177/0363546504267356.
[16] Ozgönenel L, Aytekin E, Durmuşoglu G. A double-blind
trial of clinical effects of therapeutic ultrasound in knee
osteoarthritis. Ultrasound Med Biol. 2009;35(1):44–9;
doi: 10.1016/j.ultrasmedbio.2008.07.009.
[17] Katzap Y, Haidukov M, Berland OM, Itzhak RB, Kalich-
man L. Additive effect of therapeutic ultrasound in the
treatment of plantar fasciitis: a randomized controlled
trial. J Orthop Sports Phys Ther. 2018;48(11):847–55.
[18] Waterman BR, Owens BD, Davey S, Zacchilli MA, Bel-
mont PJ, Jr. The epidemiology of ankle sprains in the
United States. J Bone Joint Surg Am. 2010;92(13):2279–
84; doi: 10.2106/JBJS.I.01537.
[19] Suksri T, Gaogasigam C, Boonyong S. Intra-rater and
inter-rater reliability and minimum detectable change of
visual analog scale and digital goniometer in patients
with subacute unilateral lateral ankle sprain. Chula Med
J. 2022;66(4):411–17; doi: 10.58837/CHULA.CMJ.66.4.5.
[20] Draper DO. Facts and misfits in ultrasound therapy:
steps to improve your treatment outcomes. Eur J Phys
Rehabil Med. 2014;50(2):209–16.
[21] Baker KG, Robertson VJ, Duck FA. A review of therapeu-
tic ultrasound: biophysical effects. Phys Ther. 2001;81(7):
1351–8.
[22] Draper DO, Ricard MD. Rate of temperature decay in
human muscle following 3 MHz ultrasound: the stretch-
ing window revealed. J Athl Train. 1995;30(4):304–7.
[23] Chan AK, Myrer JW, Measom GJ, Draper DO. Temper-
ature changes in human patellar tendon in response to
therapeutic ultrasound. J Athl Train. 1998;33(2):130–5.
[24] Draper DO, Castel JC, Castel D. Rate of temperature in-
crease in human muscle during 1 MHz and 3 MHz con-
tinuous ultrasound. J Orthop Sports Phys Ther. 1995;
22(4):142–50; doi: 10.2519/jospt.1995.22.4.142.
[25] Baker RJ, Bell GW. The effect of therapeutic modalities
on blood flow in the human calf. J Orthop Sports Phys
Ther. 1991;13(1):23–7; doi: 10.2519/jospt.1991.13.1.23.
[26] Baker KG, Robertson VJ, Duck FA. A review of thera-
peutic ultrasound: biophysical effects. Phys Ther. 2001;
81(7):1351–8.
[27] Draper DO, Prentice WE. Therapeutic ultrasound. In:
Prentice WE, Quillen WS, Underwood F (eds.) Thera-
peutic Modalities in Rehabilitation. 4th ed. New York: The
McGraw-Hill Companies; 2011, pp. 363–85.
[28] Hsieh Y-L. Reduction in induced pain by ultrasound may
be caused by altered expression of spinal neuronal ni-
tric oxide synthase-producing neurons. Arch Phys Med
Rehabil. 2005;86(7):1311–7; doi: 10.1016/j.apmr.2004.
12.035.
[29] Binder A, Hodge G, Greenwood AM, Hazleman BL, Page
Thomas DP. Is therapeutic ultrasound effective in treat-
ing soft tissue lesions? Br Med J. 1985;290:512–4; doi:
10.1136/bmj.290.6467.512.
[30] Ebenbichler GR, Resch KL, Nicolakis P, Wiesinger GF,
Uhl F, Ghanem AH, Fialka V. Ultrasound treatment for
treating the carpal tunnel syndrome: randomised “sham”
controlled trial. BMJ. 1998;316(7133):731–5; doi: 10.1136
/bmj.316.7133.731.
[31] Ebenbichler GR, Erdogmus CB, Resch KL, Funovics MA,
Kainberger F, Barisani G, Aringer M, Nicolakis P, Wies-
inger GF, Baghestanian M, Preisinger E, Weinstabl R,
Fialka-Moser V. Ultrasound therapy for calcific tendinitis
of the shoulder. N Engl J Med. 1999;340(20):1533–8;
doi: 10.1056/NEJM199905203402002.
[32] Cullum N, Liu Z. Therapeutic ultrasound for venous leg
ulcers. Cochrane Database Syst Rev. 2017;5:CD001180;
doi: 10.1002/14651858.CD001180.pub4.
[33] Parker R, Madden V. Ultrasound v. sham ultrasound for
experimentally induced delayed-onset muscle soreness:
a double-blind, randomised controlled trial. S Afr J Sports
Med. 2014;26(4):99–103.
[34] Castelnuovo G, Giusti EM, Manzoni GM, Saviola D, Ga-
brielli S, Lacerenza M, Pietrabissa G, Cattivelli R, Spa-
tola CAM, Rossi A, Varallo G, Novelli M, Villa V, Luz-
zati F, Cottini A, Lai C, Volpato E, Cavalera C, Pagnini F,
Tesio V, Castelli L, Tavola M, Torta R, Arreghini M, Za-
nini L, Brunani A, Seitanidis I, Ventura G, Capodaglio P,
D’Aniello GE, Scarpina F, Brioschi A, Bigoni M, Priano L,
Mauro A, Riva G, Di Lernia D, Repetto C, Regalia C, Mo-
linari E, Notaro P, Paolucci S, Sandrini G, Simpson S,
Wiederhold BK, Gaudio S, Jackson JB, Tamburin S, Be-
nedettiF, on behalf of the Italian Consensus Conference
on Pain in Neurorehabilitation. What is the role of the pla-
cebo effect for pain relief in neurorehabilitation? Clinical
implications from the italian consensus conference on
pain in neurorehabilitation. Front Neurol. 2018;9:310;
doi: 10.3389/fneur.2018.00310.
[35] Medoff ZM, Colloca L. Placebo analgesia: understand-
ing the mechanisms. Pain Manag. 2015;5(2):89–96; doi:
10.2217/pmt.15.3.
[36] Geri T, Viceconti A, Minacci M, Testa M, Rossettini G.
Manual therapy: exploiting the role of human touch. Mus-
culoskelet Sci Pract. 2019;44:102044; doi: 10.1016/j.
msksp.2019.07.008.
[37] Melzack R. Gate control theory: on the evolution of pain
concepts. Pain Forum. 1996;5(2):128–38; doi: 10.1016/
S1082-3174(96)80050-X.
[38] Sluka KA, Walsh DM. Transcutaneous electrical nerve
stimulation and interferential therapy. In: Sluka KA (ed.)
Mechanisms and Management of Pain for the Physical
Therapist. 2nd ed. Hong Kong: Wolters Kluwer; 2016,
pp. 314–48.
[39] Wright A. Exploring the evidence for using TENS to re-
lieve pain. Nurs Times. 2012;108(11):20–3.
