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Achilles Tendinopathy in Club Runners
Article in International Journal of Sports Medicine · May 2012
DOI: 10.1055/s-0032-1313785 · Source: PubMed
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IJSM/2377/16.1.2012/Macmillan
IJSM/2377/16.1.2012/Macmillan
Orthopedics & Biomechanics
Achilles Tendinopathy in Club Runners
Authors
Affiliations
Key words
▶ ultrasound
●
▶ athletes
●
▶ tendons
●
▶ symptoms
●
Z. Shaikh1, M. Perry1, D. Morrissey1, M. Ahmad2, A. Del Buono3, N. Maffulli1
1
Barts and The London School of Medicine and Dentistry, Centre for Sports and Exercise Medicine, United Kingdom
Barts and The London School of Medicine and Dentistry, Radiology, Queen Mary University of London, United Kingdom
3
University Campus Bio Medico, Department of Orthopaedic and Trauma Surgery, Rome, Italy
2
Abstract
▼
Ultrasound (US) changes within the Achilles
tendon are present in asymptomatic Achilles
individuals. We assessed the association of US
signs with symptoms of Achilles tendinopathy in a study group of club level running athletes and in a control group of athletes training
at least 2 times per week. The Achilles tendon
was assessed in its entirety on longitudinal US
scans, at the musculotendinous junction (MTJ),
the calcaneal insertion site, and at a midtendon
point. 25 middle distance runners, 19 males and
6 females, aged from 18 to 58, were enrolled
in each group. When compared to control ath-
Introduction
▼
accepted after revision
November 24, 2011
Bibliography
DOI http://dx.doi.org/
10.1055/s-0031-1299701
Int J Sports Med 2012; 33:
1–5 © Georg Thieme
Verlag KG Stuttgart · New York
ISSN 0172-4622
Correspondence
Prof. Nicola Maffulli
Queen Mary University of
London
Centre for Sports and Exercise
Medicine
275 Bancroft Road
E1 4DG London
United Kingdom
Tel.: +44/20/8223 8839
Fax: +44/20/8223 8930
n.maffulli@qmul.ac.uk
Tendinopathy of the main body of the Achilles
tendon is a common overuse injury [10] in runners and jumpers [1, 2, 37]. Classically, discomfort occurs at the beginning and immediately
after exercise, and improves during activity [14].
Over time, pain, swelling and stiffness may limit
training performance, and induce athletes to prematurely abandon the sport career [10, 13, 24, 40].
In elite track and field, about 50 % of middle and
long distance veteran runners complain of symptoms of Achilles tendinopathy in their lifetime,
with higher incidence of ruptures in sprinters
[16–19]. The incidence of Achilles tendinopathy
in elite, development and club level tri-athletes is
comparable [39], but little attention has been
paid on club level activities [21].
With MRI and clinical examination, ultrasonography (US) is a suitable validated tool for diagnosis
of Achilles tendinopathy [3, 6, 35]. Focal thickening, blurred paratenon margins, hypoechoic areas
and tendon neovascularization are the most common findings [4, 8, 24, 31, 32].
letes, club level runners presented significantly
increased tendon thickness (p = 0.046) at the
musculo-tendinous junction, and increased tendon thickness, with no statistical significance,
at the other landmarks points. Although club
level runners were significantly more symptomatic and predisposed to develop signs of
tendinopathy than control athletes (p = < 0.001),
ultrasound abnormalities were not significantly
associated with local symptoms complained at
the US investigation time. Prospective studies on
asymptomatic athletes are needed to define the
predictive value of US signs of Achilles tendinopathy in the development of symptoms in the
long-term.
Since symptoms of Achilles tendinopathy occur
regardless of US scans findings, the role of US
imaging assessment of patients with asymptomatic Achilles tendon changes is still unclear [22–
24]. Up to 90 % of tendons with US evidence of
tendinopathic changes are asymptomatic [15, 20],
and similar pathological features may be found in
asymptomatic and symptomatic tendons [38] as
expression of a continuum of a failed healing
response [24, 38]. However, symptoms may be
independent from the presence of intratendinous
changes.
Tendinopathic changes may become symptomatic
over time, and US changes should be better investigated in subjects with asymptomatic Achilles
tendon changes to ascertain whether targeted
interventions may prevent further changes and
decrease the rate of onset of symptoms [25, 30].
This study assessed the prevalence of ultrasound
signs and symptoms of Achilles tendinopathy in
club level running athletes, and describes the
association between US and clinical findings.
■ Proof copy for correction only. All forms of publication, duplication or distribution prohibited under copyright law. ■
Shaikh Z et al. Achilles Tendinopathy in Club Runners. Int J Sports Med 2012; 33: 1–5
1
2 Orthopedics & Biomechanics
Materials and Methods
▼
This study was approved by the Institutional Review Board and
Ethical Committee of the Queen Mary University of London and
was in agreement with the ethical standards of the journal [12].
All the athletes, recruited from London Heathside Athletics Club,
gave their written informed consent to participate in the study.
Athletes training at least 2 times per week were included in the
control group. The 2 groups were matched for sex and age.
Anthropometric data (height, weight and BMI) were measured,
and information on leg dominance, age and gender were collected. A self-administered questionnaire provided further
information on type of sport, average number of training sessions per week, number of years of training at that level, occurrence and duration of symptoms of Achilles tendinopathy in the
past and at present time, and missing time from sport activities.
The same questionnaire was administered to study and control
athletes, except for questions pertaining to the type of club
activity, referred only to the study group. Symptoms of Achilles
tendinopathy were listed as pain, tenderness, and stiffness [14].
Subjects were also asked whether symptoms were present at the
time of them filling in the questionnaire investigation, in the last
month, in the last 3 months, or at any time during their life.
US imaging
All US investigations were performed by a single experienced
musculoskeletal radiologist unaware of the questionnaire information. High-resolution 3–12 MHz linear transducers (Volusoni, GE Medical Systems, UK) and Achilles tendon setting were
used to optimize ultrasound assessments. With the subject
prone, the heels overhanging couch, and the ankles flexed to 90 °,
each Achilles tendon was entirely assessed in the longitudinal
plane. To avoid potential artifacts, the transducer was positioned
perpendicular to the tendon fibres. The Achilles tendon thickness, measured in centimeters, was entirely assessed along its
length. To exactly repeat the measures, measurement were carried out on longitudinal scans, at the musculotendinous junction (MTJ), the calcaneal insertion site (CI), and at a midtendon
point. Tendon abnormalities were classified according to the
grey-scale grading system.
To assess tendon vascularity, Power Doppler (PD) settings were
standardised with a gain of 68 dB, sensitivity of 8 cm/s, and pulse
repetition frequency of 800–1 000 Hz. On longitudinal scans,
tendon abnormalities were classified as focal thickening, hypoechoic areas, paratenon blurring and neovascularization. Tendons
images were anonymized, scanned, saved, and successively
examined by a second radiologist in a blind fashion. The measurements were repeated the same day. The coefficient of variation (CV) of the measurement obtained at the 3 landmark points
was calculated.
IJSM/2377/16.1.2012/Macmillan
IJSM/2377/16.1.2012/Macmillan
chi-square test was used to assess the relationship between
symptoms and US findings. Confidence intervals of 95 % were
calculated. A significance level of 0.05 was used. SPSS version
17.0 was used to analyze the data.
Based on the result of a previous pilot study assessing Achilles
tendinopathy in elite gymnasts, a total sample size of 98 tendons
(49 tendons per group) was required to obtain statistical significance at .05 level with a power of 80 % power. We therefore
enrolled 50 tendons per group in this study.
Results
▼
25 middle distance runners, 19 males and 6 females, aged from
18 to 58, were enrolled in each group. Both the Achilles tendons
were assessed in each subject. Anthropometric data for both
▶ Table 1.
groups and inter-group differences are shown in ●
Ultrasound tendon thickness measurements
▶ Table 2). EstiICC and LOA showed good intra-test reliability (●
mated marginal mean (EMM) and standard error (SE) values of
tendon thickness measurements were calculated for each ten▶ Table 3).
don landmark (●
The distribution of the tendon thickness values measured at the
▶ Fig. 1). At the muscmusculo-tendinous junction was normal (●
ulo-tendinous junction, club level runners presented significantly
increased tendon thickness (p = 0.046) than control athletes
▶ Table 3; ●
▶ Fig. 2). Regarding the other landmarks points, club
(●
level runners also had increased tendon thickness, but no statistical
Table 1 Anthropometric data of athlete and control groups.
Variable
Group
t-test p-value
Mean (SD)
(equal variances
not assumed)
age (years)
height (m)
weight (kg)
BMI
gender; male:female
Athlete
34.2 (13.0)
1.74 (0.08)
69.68 (9.39)
22.82 (1.71)
38:12
Control
31.3 (15.1)
1.68 (0.08)
66.16 (15.39)
23.36 (4.10)
38:12
0.303
< 0.001
0.171
0.393
Table 2 Results of intra-reliability tests using intraclass correlation coefficients and limits of agreement.
Point along tendon
ICC
LOA
longitudinal CI
longitudinal midtendon
longitudinal MTJ
0.964
0.718
0.680
0.04
0.05
0.13
Statistical analysis
Intra-class correlation coefficients (ICCs) [5] and limits of agreement (LOA) [5] were used for intra-reliability statistical analysis.
Continuous data were firstly assessed to establish distribution,
by observing frequency histograms, and parametric nature.
Independent t-tests and chi-square tests were used for comparison of continuous (age, height and weight) and categorical
(symptoms) variables between the 2 groups. Univariate analysis
of variance (ANOVA) for repeated measures was used to assess
for significant changes in the mean thickness of the tendon. The
Table 3 Estimated marginal means (EMM) for tendon thickness at insertion,
mid-point and musculotendinous junction.
Variable
longitudinal CI
longitudinal midtendon
longitudinal MTJ
Athlete
EMM
0.374
0.489
0.453
SE
0.011
0.030
0.016
Control
EMM
0.361
0.455
0.414
SE
0.011
0.020
0.016
P-value
0.434
0.247
0.046
Adjusted for height, with height = 1.71 m
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Shaikh Z et al. Achilles Tendinopathy in Club Runners. Int J Sports Med 2012; 33: 1–5
IJSM/2377/16.1.2012/Macmillan
IJSM/2377/16.1.2012/Macmillan
Orthopedics & Biomechanics
significance was found. The CV of the 3 tendon measurements,
with an average thickness of 0.22 mm for the club level runners and
0.17 mm for the control group, did not show a statistically signifi▶ Fig. 3).
cant inter-group difference (p = 0.091) (●
Symptoms of achilles tendinopathy
Club middle distance runners were significantly more symptomatic than control those for all categories of symptoms reported
▶ Table 4).
in the questionnaire (●
Ultrasound signs of achilles tendinopathy
A tendon was classified as abnormal if at least one of the above
cited abnormalities was found at ultrasound assessment. Signs
of tendinopathy were detected in 18 of 50 (36 %) tendons for the
club level runners, and in 2 of 50 (4 %) tendons for the control
group (p = < 0.001). At the time of the US scan, 8 club level runners (8 tendons), all with changes at US, were symptomatic. No
control subjects reported any symptoms. On the other hand, all
the 16 club runners (20 tendons) with US changes had reported
some symptoms in the relevant Achilles tendon in the last
month.
12
10
Frequency
8
6
4
Discussion
▼
2
0
0.200
0.400
0.600
0.800
Longitudinal myotendinous junction
Fig. 1 Normal distribution of measures at longitudinal musculotendinous junction.
MTJ Thickness
Thickness measurement (cm)
0.48
0.46
0.44
0.42
0.40
0.38
0.36
Long MTJ
Control
Athletes
Fig. 2 Thickness of musculotendinous junction in athletes compared
with controls.
Longitudinal CV Measurements
0.25
CV Value
0.20
0.15
0.10
0.05
0
Longitudinal CV
Control
Athlete
Fig. 3 Coefficient of Variation (CV) of thickness measurements in athlete
compared with control group.
Achilles tendinopathy influences performance and training in
elite track athletes, but little is known for middle distance runners active at club levels. This study shows significantly higher
incidence of symptoms of Achilles tendinopathy and ultrasound
abnormalities in club level athletes than in control subjects. In
addition, club level athletes had greater tendon thickness than
control, those with statistical significance only at the muscletendon junction. Nicol et al. [30], in a comparative analysis of
active and inactive subjects, reported US evidence of fusiform
thickening in 14 (5.6 %) of 252 Achilles tendons examined, all in
the active group. Increased thickness is a sign of tendinopathy or
an overuse response to repeated loads and stresses [41]. Hypoechoic lesions were also found in 41 of 50 tendons (84 %) of
patients with history of previous Achilles tendon pain, particularly in those most active. Malliaras et al., in a study reporting on
greyscale US changes in tendinopathy, stated that tendons containing a hypoechoic region are more likely to be painful, and
contain Doppler flow more than diffusely thickened tendons
[26]. Even though US hypoechoic changes are known to be markedly abnormal areas which contain an increased amount of
glicosoaminoglicans [29], the relationship between US, histopathological and clinical features is still unclear.
In the present study, subjects had mostly been symptomatic in
the last 3 months or in the long-term, and only few athletes
reported symptoms at the time of the US examination. 3 out of 4
athletes (75 %) symptomatic at the moment of US examination,
and 4 of 5 subjects with symptoms over the last month had
ultrasound signs of tendinopathy. Although US is more sensitive
and specific in detecting signs of Achilles tendinopathy in subjects who complain of long-time symptoms [24, 27], the relatively low number of subjects does not allow to extend our
findings to all club runners. The relationship between occurrence of US changes and subjects’ symptoms is not clear [28, 34].
We found positive ultrasound signs in 25 % of asymptomatic athletes. Nicol et al. [30] found hypoechoic regions in 88 of 149 tendons (59 %) of asymptomatic athletes. Hypoechoic regions were
also found in 41 of 50 tendons (84 %) of patients with history of
previous Achilles tendon pain, particularly in those most active.
It is possible that our asymptomatic athletes with positive US
findings have been assessed in a pre-symptomatic phase, as soon
as these US changes, present for a long time, could be not relevant from a clinical standpoint. Fredberg and Bolvig [9] reported
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Shaikh Z et al. Achilles Tendinopathy in Club Runners. Int J Sports Med 2012; 33: 1–5
3
4 Orthopedics & Biomechanics
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IJSM/2377/16.1.2012/Macmillan
Table 4 Achilles tendinopathy symptoms in the athlete group.
Symptoms
now
ever
pain in last month
continuing pain for 3 months
on/off pain for 3 months
Athlete
% with symptoms
8
42
20
12
30
Chi-square value
4.167
23.310
11.111
6.383
17.647
US tendinopathic changes in 11 of 96 Achilles and patellar tendons of asymptomatic soccer players, 45 % of whom (5 tendons)
developed symptoms in the long-term. On the other hand,
Ohberg et al. [33], in a 4-year follow-up study, found normalised
ultrasound tendon structure and reduced thickness in 19 of 26
painful Achilles undergoing eccentric training. The subjects with
increased risk to develop symptoms could preventively undergo
strategies of management, but the scientific evidence supporting that special activities or exercises may prevent further development of degenerative tendon changes and symptoms in
asymptomatic athletes is scant. Prophylactic eccentric training
and stretching programs reduce the risk of developing US abnormalities in patients with symptoms of patellar tendinopathy, but
the risk of tendon injury is increased [10]. Also, in asymptomatic
football players with US abnormal Achilles tendons, prophylactic eccentric training and stretching have no effect in reducing
neither the risk of development of US abnormalities nor the risk
of occurrence of tendon injury [10]. Further investigations are
needed to define the factors involved in the long-term development of symptoms in subjects with US signs of Achilles tendinopathy. The BMI of athletes and controls were comparable, and
statistically not different. It has been shown that adiposity and
its distribution may exert an influence on the rate of development of patellar tendinopathy in athletes [7, 11]. We are not
aware of any studies ascertaining the possible association of
height alone and Achilles tendinopathy. While we do not question that the athletes were statistically significantly taller than
the controls, we doubt that this difference bears any clinical relevance, in the presence of a similar BMI.
This study presents several weaknesses. Firstly, we enrolled the
minimum sample size to obtain statistically significant findings,
and the number of subjects is relatively small. There was evidence of a statistically significant association of US signs with
symptoms only in subjects with symptoms in the last month,
not in those who were symptomatic on the day of US examination. This result does not arise from the ability of the primary
investigator to identify US signs of pathology, and, reviewing the
scans, the findings were confirmed. Because the risk of developing Achilles tendinopathy is related to the type of sport activity
[36, 38], this is a potential confounding factor of the present
study. However, all our athletes were track runners.
The wide range of age of the athletes could have influenced results,
with the older athletes more likely to become symptomatic for
Achilles tendinopathy. To avoid this bias, in our study, the 2 groups
were matched for age. Since the athletes were examined only once,
we are not aware of the evolution of symptoms and US changes.
Strength of the study is that 2 US investigations were performed for
each subject by a musculoskeletal radiologist, unaware of the clinical and questionnaire information, and imaging findings were
reviewed by a second blinded investigator.
Control
% with symptoms
0
2
0
0
0
P-value
Chi-square value
4.167
23.310
11.111
6.383
17.647
0.041
< 0.001
0.001
0.012
< 0.001
Conclusion
▼
Compared to control athletes, club level runners are more prone
to develop symptoms and US signs of Achilles tendinopathy,
with increased thickness of the muscle tendon junction. Prospective studies on asymptomatic athletes are needed to define
the predictive value of US signs of Achilles tendinopathy in the
development of symptoms in the long-term.
References
1 Alfredson H. Chronic midportion Achilles tendinopathy: an update on
research and treatment. Clin Sports Med 2003; 22: 727–741
2 Ames PR, Longo UG, Denaro V, Maffulli N. Achilles tendon problems:
not just an orthopaedic issue. Disabil Rehabil 2008; 30: 1646–1650
3 Astrom M, Gentz CF, Nilsson P, Rausing A, Sjoberg S, Westlin N. Imaging
in chronic Achilles tendinopathy: a comparison of ultrasonography,
magnetic resonance imaging and surgical findings in 27 histologically
verified cases. Skeletal Radiol 1996; 25: 615–620
4 Astrom M, Westlin N. Blood flow in chronic Achilles tendinopathy.
Clin Orthop Relat Res 1994; 308: 166–172
5 Bland JM, Altman DG. Statistical methods for assessing agreement
between two methods of clinical measurement. Lancet 1986; 1:
307–310
6 Bleakney RR, Tallon C, Wong JK, Lim KP, Maffulli N. Long-term ultrasonographic features of the Achilles tendon after rupture. Clin J Sport
Med 2002; 12: 273–278
7 Culvenor AG, Cook JL, Warden SJ, Crossley KM. Infrapatellar fat pad
size, but not patellar alignment, is associated with patellar tendinopathy. Scand J Med Sci Sports. doi:10.1111/j.1600-0838.2011.01334.x
In press
8 Fornage BD. The hypoechoic normal tendon. A pitfall. J Ultrasound
Med 1987; 6: 19–22
9 Fredberg U, Bolvig L. Significance of ultrasonographically detected
asymptomatic tendinosis in the patellar and achilles tendons of elite
soccer players: a longitudinal study. Am J Sports Med 2002; 30:
488–491
10 Fredberg U, Bolvig L, Andersen NT. Prophylactic training in asymptomatic soccer players with ultrasonographic abnormalities in Achilles
and patellar tendons: the Danish Super League Study. Am J Sports
Med 2008; 36: 451–460
11 Gaida JE, Cook JL, Bass SL, Austen S, Kiss ZS. Are unilateral and bilateral
patellar tendinopathy distinguished by differences in anthropometry,
body composition, or muscle strength in elite female basketball players? Br J Sports Med 2004; 38: 581–585
12 Harriss DJ, Atkinson G. Update – Ethical standards in sport and exercise science research. Int J Sports Med 2011; 32: 819–821
13 Jarvinen TA, Kannus P, Maffulli N, Khan KM. Achilles tendon disorders:
etiology and epidemiology. Foot Ankle Clin 2005; 10: 255–266
14 Kader D, Saxena A, Movin T, Maffulli N. Achilles tendinopathy: some
aspects of basic science and clinical management. Br J Sports Med
2002; 36: 239–249
15 Kannus P, Jozsa L. Histopathological changes preceding spontaneous
rupture of a tendon. A controlled study of 891 patients. J Bone Joint
Surg Am 1991; 73: 1507–1525
16 Kannus P, Niittymaki S, Jarvinen M, Lehto M. Sports injuries in elderly
athletes: a three-year prospective, controlled study. Age Ageing 1989;
18: 263–270
17 Knobloch K, Yoon U, Vogt PM. Acute and overuse injuries correlated
to hours of training in master running athletes. Foot Ankle Int 2008;
29: 671–676
18 Kujala UM, Sarna S, Kaprio J. Cumulative incidence of Achilles tendon
rupture and tendinopathy in male former elite athletes. Clin J Sport
Med 2005; 15: 133–135
■ Proof copy for correction only. All forms of publication, duplication or distribution prohibited under copyright law. ■
Shaikh Z et al. Achilles Tendinopathy in Club Runners. Int J Sports Med 2012; 33: 1–5
IJSM/2377/16.1.2012/Macmillan
IJSM/2377/16.1.2012/Macmillan
19 Kvist M. Achilles tendon injuries in athletes. Sports Med 1994; 18:
173–201
20 Leppilahti J, Orava S. Total Achilles tendon rupture. A review. Sports
Med 1998; 25: 79–100
21 Longo UG, Rittweger J, Garau G, Radonic B, Gutwasser C, Gilliver SF,
Kusy K, Zieliński J, Felsenberg D, Maffulli N. No influence of age, gender,
weight, height, and impact profile in Achilles tendinopathy in masters
track and field athletes. Am J Sports Med 2009; 37: 1400–1405
22 Maffulli N, Dymond NP, Capasso G. Ultrasonographic findings in subcutaneous rupture of Achilles tendon. J Sports Med Phys Fitness 1989;
29: 365–368
23 Maffulli N, Longo UG, Maffulli GD, Rabitti C, Khanna A, Denaro V.
Marked pathological changes proximal and distal to the site of rupture in acute Achilles tendon ruptures. Knee Surg Sports Traumatol
Arthrosc 2011; 19: 680–687
24 Maffulli N, Regine R, Angelillo M, Capasso G, Filice S. Ultrasound diagnosis of Achilles tendon pathology in runners. Br J Sports Med 1987;
21: 158–162
25 Maffulli N, Sharma P, Luscombe KL. Achilles tendinopathy: aetiology
and management. J R Soc Med 2004; 97: 472–476
26 Malliaras P, Purdam C, Maffulli N, Cook J. Temporal sequence of greyscale ultrasound changes and their relationship with neovascularity
and pain in the patellar tendon. Br J Sports Med 2010; 44: 944–947
27 Malliaras P, Richards PJ, Garau G, Maffulli N. Achilles tendon Doppler flow may be associated with mechanical loading among active
athletes. Am J Sports Med 2008; 36: 2210–2215
28 Malliaras P, Voss C, Garau G, Richards P, Maffulli N. Achilles tendon
shape and echogenicity on ultrasound among active badminton players. Scand J Med Sci Sports
29 Movin T, Kristoffersen-Wiberg M, Shalabi A, Gad A, Aspelin P, Rolf C.
Intratendinous alterations as imaged by ultrasound and contrast
medium-enhanced magnetic resonance in chronic achillodynia. Foot
Ankle Int 1998; 19: 311–317
30 Nicol AM, McCurdie I, Etherington J. Use of ultrasound to identify
chronic Achilles tendinosis in an active asymptomatic population.
J R Army Med Corps 2006; 152: 212–216
Orthopedics & Biomechanics
31 O’Connor PJ, Grainger AJ, Morgan SR, Smith KL, Waterton JC, Nash AF.
Ultrasound assessment of tendons in asymptomatic volunteers: a
study of reproducibility. Eur Radio 2004; 14: 1968–1973
32 Ohberg L, Lorentzon R, Alfredson H. Neovascularisation in Achilles tendons with painful tendinosis but not in normal tendons: an
ultrasonographic investigation. Knee Surg Sports Traumatol Arthrosc
2001; 9: 233–238
33 Ohberg L, Lorentzon R, Alfredson H. Eccentric training in patients
with chronic Achilles tendinosis: normalised tendon structure and
decreased thickness at follow up. Br J Sports Med 2004; 38: 8–11
34 Paavola M, Kannus P, Paakkala T, Pasanen M, Jarvinen M. Long-term
prognosis of patients with achilles tendinopathy. An observational
8-year follow-up study. Am J Sports Med 2000; 28: 634–642
35 Paavola M, Paakkala T, Kannus P, Jarvinen M. Ultrasonography in the
differential diagnosis of Achilles tendon injuries and related disorders.
A comparison between pre-operative ultrasonography and surgical
findings. Acta Radiol 1998; 39: 612–619
36 Richards PJ, McCall IW, Day C, Belcher J, Maffulli N. Longitudinal
microvascularity in Achilles tendinopathy (power Doppler ultrasound,
magnetic resonance imaging time-intensity curves and the Victorian
Institute of Sport Assessment-Achilles questionnaire): a pilot study.
Skeletal Radiol 2010; 39: 509–521
37 Silbernagel KG, Gustavsson A, Thomee R, Karlsson J. Evaluation of lower
leg function in patients with Achilles tendinopathy. Knee Surg Sports
Traumatol Arthrosc 2006; 14: 1207–1217
38 Tallon C, Maffulli N, Ewen SW. Ruptured Achilles tendons are significantly more degenerated than tendinopathic tendons. Med Sci Sports
Exerc 2001; 33: 1983–1990
39 Vleck VE, Garbutt G. Injury and training characteristics of male elite,
development squad, and club triathletes. Int J Sports Med 1998; 19:
38–42
40 Vora AM, Myerson MS, Oliva F, Maffulli N. Tendinopathy of the main
body of the Achilles tendon. Foot Ankle Clin 2005; 10: 293–308
41 Ying M, Yeung E, Li B, Li W, Lui M, Tsoi CW. Sonographic evaluation
of the size of Achilles tendon: the effect of exercise and dominance
of the ankle. Ultrasound Med Biol 2003; 29: 637–642
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