Patellar and Achilles Tendon Stiffness in Elite Soccer Players Assessed Using Myotonometric Measurements

Background: Tendon overuse injuries are an issue in elite footballers (soccer players) and may affect tendon function. Achilles and patellar tendinopathy are the most frequent pathologies. Tendon stiffness, the relationship between the force applied to a tendon and the displacement exerted, may help represent tendon function. Stiffness is affected by training and pathology. Nevertheless, information regarding this mechanical property is lacking for elite soccer athletes. Hypothesis: Achilles and patellar tendon stiffness assessed using myotonometric measurements will be greater in elite soccer athletes than in control participants. Study Design: Cross-sectional study. Level of Evidence: Level 4. Methods: Forty-nine elite soccer athletes and 49 control participants were evaluated during the 2017 preseason. A handheld device was used to measure Achilles and patellar tendon stiffness. Dominant and nondominant limbs were assessed for both groups. Results: A significantly stiffer patellar tendon was found for both the dominant and the nondominant limb in the elite soccer athletes compared with the control group. Nevertheless, no differences were found in Achilles tendon stiffness between groups. When comparing between playing positions in soccer athletes, no significant differences were found for both tendons. Conclusion: Greater patellar tendon stiffness may be related to an improvement in force transmission during muscle contraction. On the other hand, it seems that after years of professional training, Achilles tendon stiffness does not change, conserving the storing-releasing function of elastic energy. The nonsignificant differences between positions may be attributable to the years of homogeneous training that the players underwent. Clinical Relevance: The present study shows another technique for measuring mechanical properties of tendons in soccer athletes that could be used in clinical settings. In the future, this technique may help clinicians choose the best exercise protocol to address impairments in tendon stiffness.

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Influence of acute and chronic streptozotocin-induced diabetes on the rat tendon extracellular matrix and mechanical properties

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00189.2015 ◽

2015 ◽

Vol 309 (9) ◽

pp. R1135-R1143 ◽

Cited By ~ 18

Author(s):

Brent D. Volper ◽

Richard T. Huynh ◽

Kathryn A. Arthur ◽

Joshua Noone ◽

Benjamin D. Gordon ◽

...

Keyword(s):

Mechanical Properties ◽

Achilles Tendon ◽

Patellar Tendon ◽

Collagen Content ◽

Control Group ◽

Diabetic Patients ◽

Insulin Group ◽

Chronic Group ◽

Acute Group ◽

Streptozotocin Induced Diabetes

Diabetes is a major risk factor for tendinopathy, and tendon abnormalities are common in diabetic patients. The purpose of the present study was to evaluate the effect of streptozotocin (60 mg/kg)-induced diabetes and insulin therapy on tendon mechanical and cellular properties. Sprague-Dawley rats ( n = 40) were divided into the following four groups: nondiabetic (control), 1 wk of diabetes (acute), 10 wk of diabetes (chronic), and 10 wk of diabetes with insulin treatment (insulin). After 10 wk, Achilles tendon and tail fascicle mechanical properties were similar between groups ( P > 0.05). Cell density in the Achilles tendon was greater in the chronic group compared with the control and acute groups (control group: 7.8 ± 0.5 cells/100 μm2, acute group: 8.3 ± 0.4 cells/100 μm2, chronic group: 10.9 ± 0.9 cells/100 μm2, and insulin group: 9.2 ± 0.8 cells/100 μm2, P < 0.05). The density of proliferating cells in the Achilles tendon was greater in the chronic group compared with all other groups (control group: 0.025 ± 0.009 cells/100 μm2, acute group: 0.019 ± 0.005 cells/100 μm2, chronic group: 0.067 ± 0.015, and insulin group: 0.004 ± 0.004 cells/100 μm2, P < 0.05). Patellar tendon collagen content was ∼32% greater in the chronic and acute groups compared with the control or insulin groups (control group: 681 ± 63 μg collagen/mg dry wt, acute group: 938 ± 21 μg collagen/mg dry wt, chronic: 951 ± 52 μg collagen/mg dry wt, and insulin group: 596 ± 84 μg collagen/mg dry wt, P < 0.05). In contrast, patellar tendon hydroxylysyl pyridinoline cross linking and collagen fibril organization were unchanged by diabetes or insulin ( P > 0.05). Our findings suggest that 10 wk of streptozotocin-induced diabetes does not alter rat tendon mechanical properties even with an increase in collagen content. Future studies could attempt to further address the mechanisms contributing to the increase in tendon problems noted in diabetic patients, especially since our data suggest that hyperglycemia per se does not alter tendon mechanical properties.

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Influence of Badminton Practice on Age-Related Changes in Patellar and Achilles Tendons

Journal of Aging and Physical Activity ◽

10.1123/japa.2020-0215 ◽

2020 ◽

pp. 1-9

Author(s):

Alfredo Bravo-Sánchez ◽

Pablo Abián ◽

Filipa Sousa ◽

Fernando Jimenez ◽

Javier Abián-Vicén

Keyword(s):

Mechanical Properties ◽

Achilles Tendon ◽

Age Groups ◽

Control Group ◽

Physically Active ◽

Tendon Stiffness ◽

Sport Practice ◽

Age Related ◽

Age Related Changes

Regular sport practice could prevent age-related changes in tendinous tissues. The purpose of the study was to investigate the effect of regular badminton practice on patellar and Achilles tendon mechanical properties in senior competitive badminton players (>35 years old) and to compare the results with physically active people matched by age. One hundred ninety-two badminton players and 193 physically active people were divided by age into four groups, between 35 and 44 (U45), between 45 and 54 (U55), between 55 and 64 (U65), and over 65 (O65) years old. A LogiqS8 transducer in elastography mode and a MyotonPRO myotonometer were used to assess patellar and Achilles mechanical properties. Achilles tendon stiffness was higher in the control group than the badminton players for the U45, U55, and O65 age groups (p < .01). Also, the elastography index was higher in the control group than the badminton players for the U45, U55, U65, and O65 age groups (p < .05). In conclusion, regular badminton practice could prevent the decline in mechanical properties of the patellar and Achilles tendons.

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Training-induced increase in Achilles tendon stiffness affects tendon strain pattern during running

PeerJ ◽

10.7717/peerj.6764 ◽

2019 ◽

Vol 7 ◽

pp. e6764 ◽

Cited By ~ 3

Author(s):

Amelie Werkhausen ◽

Neil J. Cronin ◽

Kirsten Albracht ◽

Gøran Paulsen ◽

Askild V. Larsen ◽

...

Keyword(s):

Mechanical Properties ◽

Achilles Tendon ◽

Stance Phase ◽

Training Group ◽

Triceps Surae ◽

Control Group ◽

Tendon Stiffness ◽

Strain Pattern ◽

Tendon Strain ◽

Triceps Surae Muscles

Background During the stance phase of running, the elasticity of the Achilles tendon enables the utilisation of elastic energy and allows beneficial contractile conditions for the triceps surae muscles. However, the effect of changes in tendon mechanical properties induced by chronic loading is still poorly understood. We tested the hypothesis that a training-induced increase in Achilles tendon stiffness would result in reduced tendon strain during the stance phase of running, which would reduce fascicle strains in the triceps surae muscles, particularly in the mono-articular soleus. Methods Eleven subjects were assigned to a training group performing isometric single-leg plantarflexion contractions three times per week for ten weeks, and another ten subjects formed a control group. Before and after the training period, Achilles tendon stiffness was estimated, and muscle-tendon mechanics were assessed during running at preferred speed using ultrasonography, kinematics and kinetics. Results Achilles tendon stiffness increased by 18% (P < 0.01) in the training group, but the associated reduction in strain seen during isometric contractions was not statistically significant. Tendon elongation during the stance phase of running was similar after training, but tendon recoil was reduced by 30% (P < 0.01), while estimated tendon force remained unchanged. Neither gastrocnemius medialis nor soleus fascicle shortening during stance was affected by training. Discussion These results show that a training-induced increase in Achilles tendon stiffness altered tendon behaviour during running. Despite training-induced changes in tendon mechanical properties and recoil behaviour, the data suggest that fascicle shortening patterns were preserved for the running speed that we examined. The asymmetrical changes in tendon strain patterns supports the notion that simple in-series models do not fully explain the mechanical output of the muscle-tendon unit during a complex task like running.

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Association of Ankle Dorsiflexion and Landing Forces in Jumping Athletes

Sports Health A Multidisciplinary Approach ◽

10.1177/19417381211063456 ◽

2021 ◽

pp. 194173812110634

Author(s):

Adalberto Felipe Martinez ◽

Rodrigo Scattone Silva ◽

Bruna Lopes Ferreira Paschoal ◽

Laura Ledo Antunes Souza ◽

Fábio Viadanna Serrão

Keyword(s):

Patellar Tendon ◽

Loading Rate ◽

Reaction Force ◽

Ankle Dorsiflexion ◽

Patellar Tendinopathy ◽

Plantar Flexor ◽

Vertical Ground Reaction Force ◽

Level Of Evidence ◽

Ankle Kinematics ◽

Tendon Force

Background: Dorsiflexion range of motion restriction has been associated with patellar tendinopathy, but the mechanisms of how dorsiflexion restriction could contribute to knee overload remain unknown. Hypothesis: Peak ankle dorsiflexion and ankle dorsiflexion excursion are negatively associated with peak vertical ground-reaction force (vGRF) and loading rate, and with peak patellar tendon force and loading rate, and positively associated with peak ankle plantar flexor moment. Study Design: Cross-sectional study. Level of Evidence: Level 4. Methods: Kinematic and kinetic data of 26 healthy recreational jumping athletes were measured during a single-leg drop vertical jump. Pearson’s correlation coefficients were calculated to establish the association between peak ankle dorsiflexion and ankle dorsiflexion excursion with peak vGRF and vGRF loading rate, with peak patellar tendon force and patellar tendon force loading rate, and with peak ankle plantar flexor moment. Results: Ankle dorsiflexion excursion negatively correlated with peak vGRF loading rate ( r = −0.49; P = 0.011) and positively correlated with peak ankle flexor plantar moment ( r = 0.52; P = 0.006). In addition, there was a positive correlation between peak ankle dorsiflexion and peak vGRF ( r = 0.39; P = 0.05). Conclusion: Ankle kinematics are associated with vGRF loading rate, ankle flexor plantar moment and peak vGRF influencing knee loads, but no association was observed between ankle kinematics and patellar tendon loads. Clinical Relevance: These results suggest that increasing ankle dorsiflexion excursion may be an important strategy to reduce lower limb loads during landings but should not be viewed as the main factor for reducing patellar tendon force.

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Extracorporeal Shockwave for Chronic Patellar Tendinopathy

The American Journal of Sports Medicine ◽

10.1177/0363546506298109 ◽

2007 ◽

Vol 35 (6) ◽

pp. 972-978 ◽

Cited By ~ 78

Author(s):

Ching-Jen Wang ◽

Jih-Yang Ko ◽

Yi-Sheng Chan ◽

Lin-Hsiu Weng ◽

Shan-Lin Hsu

Keyword(s):

Patellar Tendon ◽

Group Versus ◽

Patellar Tendinopathy ◽

Control Group ◽

Study Group ◽

Extracorporeal Shockwave Therapy ◽

Ultrasonographic Examination ◽

Extracorporeal Shockwave ◽

Shockwave Therapy ◽

Significant Difference

Background Chronic patellar tendinopathy is an overuse syndrome with pathologic changes similar to tendinopathies of the shoulder, elbow, and heel. Extracorporeal shockwave was shown effective in many tendinopathies. Hypothesis Extracorporeal shockwave therapy may be more effective than conservative treatment for chronic patellar tendinopathy. Study Design Randomized controlled clinical trial; Level of evidence, 2. Methods This study consisted of 27 patients (30 knees) in the study group and 23 patients (24 knees) in the control group. In the study group, patients were treated with 1500 impulses of extracorporeal shockwave at 14 KV (equivalent to 0.18 mJ/mm 2 energy flux density) to the affected knee at a single session. Patients in the control group were treated with conservative treatments including nonsteroidal anti-inflammatory drugs, physiotherapy, exercise program, and the use of a knee strap. The evaluation parameters included pain score, Victorian Institute of Sports Assessment score, and ultrasonographic examination at 1, 3, 6, and 12 months and then once a year. Results At the 2- to 3-year follow-up, the overall results for the study group were 43% excellent, 47% good, 10% fair, and none poor. For the control group, the results were none excellent, 50% good, 25% fair, and 25% poor. The mean Victorian Institute of Sports Assessment scores were 42.57 ± 10.22 and 39.25 ± 10.85, respectively, before treatment (P = .129) and 92.0 ± 10.17 and 41.04 ± 10.96, respectively, after treatment (P < .001). Satisfactory results were observed in 90% of the study group versus 50% of the control group (P < .001). Recurrence of symptoms occurred in 13% of the study group and 50% of the control group (P = .014). Ultrasonographic examination showed a significant increase in the vascularity of the patellar tendon and a trend of reduction in the patellar tendon thickness after shockwave treatment compared with conservative treatments. However, no significant difference in the appearance, arrangement, and homogeneity of tendon fibers was noted between the 2 groups. There were no systemic or local complications or device-related problems. Conclusion Extracorporeal shockwave therapy appeared to be more effective and safer than traditional conservative treatments in the management of patients with chronic patellar tendinopathy.

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The association between patellar tendon stiffness measured with shear-wave elastography and patellar tendinopathy—a case-control study

European Radiology ◽

10.1007/s00330-020-06952-0 ◽

2020 ◽

Vol 30 (11) ◽

pp. 5942-5951 ◽

Cited By ~ 1

Author(s):

Stephan J. Breda ◽

Arco van der Vlist ◽

Robert-Jan de Vos ◽

Gabriel P. Krestin ◽

Edwin H. G. Oei

Keyword(s):

Shear Wave ◽

Patellar Tendon ◽

Interobserver Reliability ◽

Power Doppler ◽

Shear Wave Elastography ◽

Intraobserver Reliability ◽

Patellar Tendinopathy ◽

Altman Analysis ◽

Tendon Stiffness ◽

Bland Altman Analysis

Abstract Objectives (1) To determine the association between patellar tendon stiffness and the presence of patellar tendinopathy (PT). (2) To evaluate the reliability of shear-wave elastography (SWE). Methods Participants were consecutively enrolled between January 2017 and June 2019. PT was diagnosed clinically and confirmed by either grayscale US or power Doppler US, or both. Controls had no history of anterior knee pain and no clinical signs of PT. Patellar tendon stiffness (kilopascal, kPa) was assessed using SWE. Logistic regression was used to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CIs). Reliability analyses included coefficients-of-variation (CV), coefficients-of-repeatability (CR), intraclass correlation coefficient (ICC) for intraobserver and interobserver reliability, and Bland-Altman analysis. Results In total, 76 participants with PT (58 men, mean age 24.4 ± 3.8 years) and 35 asymptomatic controls (16 men, mean age 21.5 ± 3.8 years) were included. Univariate analyses (OR 1.094, 95% CI 1.061–1.128, p < .001) and adjusted multivariate analyses (OR 1.294, 95% CI 1.044–1.605, p = .018) showed that athletes with PT had significantly increased patellar tendon stiffness. ICC for intraobserver reliability was 0.95 (95% CI 0.92–0.97), CR (CV) 12 kPa (10%) and 0.79 (95% CI 0.65–0.88), CR (CV) 18 kPa (21%) for interobserver reliability. Mean differences from Bland-Altman analysis were 5.6 kPa (95% CI 3.1–8.1, p < .001) for intraobserver reliability and 4.6 kPa (95% CI 1.9–7.2, p < .001) for interobserver reliability. Conclusions PT is associated with significantly higher patellar tendon stiffness. SWE measurements demonstrate excellent intraobserver reliability and good interobserver reliability. Therefore, SWE is a promising tool to implement in longitudinal studies and future studies should evaluate its prognostic value and utility as a monitoring tool in athletes with PT. Key Points • Patellar tendon stiffness measured with shear-wave elastography (SWE) is higher in athletes with patellar tendinopathy than in healthy controls, also after adjusting for potential confounders. • Excellent intraobserver reliability and good interobserver reliability were found for the quantitative assessment of patellar tendon stiffness using SWE.

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Early mobilization does not reduce the risk of deep venous thrombosis after Achilles tendon rupture: a randomized controlled trial

Knee Surgery Sports Traumatology Arthroscopy ◽

10.1007/s00167-019-05767-x ◽

2019 ◽

Vol 28 (1) ◽

pp. 312-319 ◽

Cited By ~ 8

Author(s):

Susanna Aufwerber ◽

Annette Heijne ◽

Gunnar Edman ◽

Karin Grävare Silbernagel ◽

Paul W. Ackermann

Keyword(s):

Venous Thrombosis ◽

Deep Venous Thrombosis ◽

Achilles Tendon ◽

Tendon Rupture ◽

Controlled Trial ◽

Achilles Tendon Rupture ◽

Control Group ◽

Level Of Evidence ◽

Treatment As Usual ◽

Patient Reported

Abstract Purpose The hypothesis was that early functional mobilization would reduce the incidence of deep venous thrombosis (DVT) during leg immobilization after Achilles tendon rupture surgery. A secondary aim was to evaluate if the amount of weightbearing and daily steps influenced the risk of sustaining a DVT. Methods One-hundred and fifty patients with Achilles tendon rupture repair were randomized to treatment with early functional mobilization, encouraging full weightbearing and ankle motion in orthosis, or treatment-as-usual, i.e., 2 weeks of unloading in plaster cast followed by 4 weeks weightbearing in orthosis. At 2 and 6 weeks postoperatively, all patients were screened for DVT using compression duplex ultrasound. During the first 2 weeks postoperatively, patient-reported loading, pain and step counts were assessed. Results At 2 weeks, 28/96 (29%) of the patients in early functional mobilization group and 15/49 (31%) in the control group (n.s) had sustained a DVT. At 6 weeks, the DVT rate was 35/94 (37%) in the early functional mobilization and 14/49 (29%) in the control group (n.s). During the first postoperative week, the early functional mobilization group reported low loading and higher experience of pain vs. the control group (p = 0.001). Low patient-reported loading ≤ 50% (OR = 4.3; 95% CI 1.28–14.3) was found to be an independent risk factor for DVT, in addition to high BMI and higher age. Conclusions Early functional mobilization does not prevent the high incidence of DVT during leg immobilization in patients with Achilles tendon rupture as compared to treatment-as-usual. The low efficacy of early functional mobilization is mainly explained by postoperative pain and subsequent low weightbearing. To minimize the risk of DVT, patients should be encouraged to load at least 50% of body weight on the injured leg 1 week after surgery. Level of evidence Therapeutic, level 1

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A Novel Method for Assessing Regional Tendon Stiffness and Its Significance

Applied Sciences ◽

10.3390/app8071156 ◽

2018 ◽

Vol 8 (7) ◽

pp. 1156

Author(s):

Siu Fu ◽

Hsing-Kuo Wang ◽

Chen Huang

Keyword(s):

Shear Modulus ◽

Patellar Tendon ◽

Patellar Tendinopathy ◽

Differential Modulation ◽

Patella Tendon ◽

Tendon Stiffness ◽

Linear Transducer ◽

Novel Method ◽

The Impact

Elastography can be used to estimate the regional shear modulus of a tendon. This can advance our knowledge on the impact of patellar alignment and regional patellar tendon stiffness. This is important as patellar tendon abnormality is mainly found in the medial portion of the tendon in subjects with proximal patellar tendinopathy. This paper aims to assess the effect of patellar displacement on differential modulation on the shear modulus of the patellar tendon. Shear modulus is captured on the medial and lateral half of the patella tendon using the Axiplorer® ultrasound unit in conjunction with a 4–15 MHz, 50 mm linear transducer with the patellar being positioned in its resting, medio- and laterally displaced positions on 40 adults (19 females, 21 males). When the patellar is displaced laterally, the shear modulus is significantly increased at the medial half in both genders but decreased at the lateral half only in females. Conclusions: Elastography detects changes in regional tendon stiffness associated with alteration in patellar positions. The modulation on the shear modulus is gender and region specific.

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INVESTIGATION OF PITUITARY DYSFUNCTION IN RETIRED PROFESSIONAL SOCCER PLAYERS

Revista Brasileira de Medicina do Esporte ◽

10.1590/1517-869220202606215617 ◽

2020 ◽

Vol 26 (6) ◽

pp. 503-507

Author(s):

Soner Akkurt ◽

Fatih Tanriverdi ◽

Nihat Kalay ◽

Zuleyha Cihan Ozdamar Karaca ◽

Kursat Unluhizarci ◽

...

Keyword(s):

Brain Injuries ◽

Threshold Value ◽

Exercise Stress ◽

Soccer Players ◽

Control Group ◽

Stress Tests ◽

Acth Stimulation ◽

Level Of Evidence ◽

Pituitary Dysfunction ◽

Professional Soccer

ABSTRACT Introduction: It is well-known that pituitary dysfunction can develop as a result of traumatic brain injuries. One reason for such injuries is collision during contact sports. Objectives: The aim of this study was to investigate the effects of heading the ball and concussion on pituitary function in retired soccer players. Methods: Thirty-two retired soccer players, with an average age of 43.38 ± 5.49 (35-59) and 26 sedentary individuals with an average age of 43.31±6.38 (35-59) were included in this study. The subjects were questioned about their soccer-playing background, history of head trauma and concussion, and cardiometabolic diseases. One day one, blood samples were taken to investigate the baseline hematologic and biochemical parameters. On day two, the ACTH stimulation test was conducted, and on day three, glucagon stimulation tests were carried out. Resting EKG, transthoracic ECHO and exercise stress tests (for MET values) were also conducted. For the statistical analysis, The Student's t-test was used to compare the results of the two groups. The level of significance adopted was p<0.05. Results: It was identified that 5 out of 32 soccer players (16%) had experienced concussion during their soccer careers. The growth hormone (GH) levels of 3 retired soccer players (9.2%) and 3 sedentary individuals (10%) was below 1 ng/dl, which was accepted as the threshold value. There were no significant differences between hematological, biochemical and cardiometabolic parameters of the soccer players with low GH levels and those with normal GH levels. There was no significant relationship between the number of headers performed and GH deficiency. Conclusion: Although low GH levels were detected in almost 10% of the retired soccer players, the frequency of hypopituitarism was not higher than in the sedentary control group. Level of evidence I; Prognostic Studies.

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Effects of Concentric and Eccentric Training on the Stiffness and Blood Circulation of the Patellar Tendon

Sports Medicine International Open ◽

10.1055/s-0042-121000 ◽

2017 ◽

Vol 01 (02) ◽

pp. E43-E49 ◽

Cited By ~ 6

Author(s):

Keitaro Kubo ◽

Hideaki Yata

Keyword(s):

Oxygen Saturation ◽

Blood Volume ◽

Patellar Tendon ◽

Blood Circulation ◽

Training Group ◽

Knee Extensors ◽

Control Group ◽

Cross Sectional ◽

Tendon Stiffness ◽

Before And After

AbstractThe aim of the present study was to investigate the effects of concentric (CON) and eccentric (ECC) training on stiffness and blood circulation of the tendon, and clarify whether relative changes in tendon stiffness are related to those in tendon blood circulation. 17 subjects were assigned to training (n=9) and control (n=8) groups. Training group completed 12 weeks of unilateral training program for knee extensors. They performed 5 sets of CON or ECC at 80% of 1RM with 10 repetitions. Before and after training, cross-sectional area, stiffness, hysteresis, blood volume, and oxygen saturation of the patellar tendon were measured. Oxygen saturation significantly increased with CON and ECC. Stiffness significantly increased with CON but not with ECC. Other measured variables did not change after training. Furthermore, the relative change in tendon stiffness did not correlate with that in blood volume or oxygen saturation. In control group, measured variables did not change after training. These results suggest that tendon stiffness increased after CON but not after ECC; however no significant differences in the changes observed in size and blood circulation of the tendon were found between 2 protocols. Furthermore, changes in tendon stiffness were not related to those in tendon blood circulation.

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