Maximum dorsiflexion increases Achilles tendon force during exercise for midportion Achilles tendinopathy

Patellar and Achilles tendinopathy commonly affect runners. Developing algorithms to predict cumulative force in these structures may help prevent these injuries. Importantly, such algorithms should be fueled with data that are easily accessible while completing a running session outside a biomechanical laboratory. Therefore, the main objective of this study was to investigate whether algorithms can be developed for predicting patellar and Achilles tendon force and impulse during running using measures that can be easily collected by runners using commercially available devices. A secondary objective was to evaluate the predictive performance of the algorithms against the commonly used running distance. Trials of 24 recreational runners were collected with an Xsens suit and a Garmin Forerunner 735XT at three different intended running speeds. Data were analyzed using a mixed-effects multiple regression model, which was used to model the association between the estimated forces in anatomical structures and the training load variables during the fixed running speeds. This provides twelve algorithms for predicting patellar or Achilles tendon peak force and impulse per stride. The algorithms developed in the current study were always superior to the running distance algorithm.

Download Full-text

Ultrasound and surgical inspection of plantaris tendon involvement in chronic painful insertional Achilles tendinopathy: a case series

BMJ Open Sport & Exercise Medicine ◽

10.1136/bmjsem-2020-000979 ◽

2021 ◽

Vol 7 (1) ◽

pp. e000979

Author(s):

Håkan Alfredson ◽

Lorenzo Masci ◽

Christoph Spang

Keyword(s):

Achilles Tendon ◽

Clinical Symptoms ◽

Fatty Infiltration ◽

Case Series ◽

Achilles Tendinopathy ◽

Level Of Evidence ◽

Plantaris Tendon ◽

Medial Pain ◽

Tendon Insertion ◽

Insertional Achilles Tendinopathy

ObjectivesChronic painful insertional Achilles tendinopathy is known to be difficult to manage. The diagnosis is not always easy because multiple different tissues can be involved. The plantaris tendon has recently been described to frequently be involved in chronic painful mid-portion Achilles tendinopathy. This study aimed to evaluate possible plantaris tendon involvement in patients with chronic painful insertional Achilles tendinopathy.MethodsNinety-nine consecutive patients (74 males, 25 females) with a mean age of 40 years (range 24–64) who were surgically treated for insertional Achilles tendinopathy, were included. Clinical examination, ultrasound (US)+Doppler examination, and surgical findings were used to evaluate plantaris tendon involvement.ResultsIn 48/99 patients, there were clinical symptoms of plantaris tendon involvement with pain and tenderness located medially at the Achilles tendon insertion. In all these cases, surgical findings showed a thick and wide plantaris tendon together with a richly vascularised fatty infiltration between the plantaris and Achilles tendon. US examination suspected plantaris involvement in 32/48 patients.ConclusionPlantaris tendon involvement can potentially be part of the pathology in chronic painful insertional Achilles tendinopathy and should be considered for diagnosis and treatment when there is distinct and focal medial pain and tenderness.Level of evidenceIV case series.

Download Full-text

The effect of fatigue on peak Achilles tendon force in Irish dancing-specific landing tasks

Sports Biomechanics ◽

10.1080/14763141.2021.1951826 ◽

2021 ◽

pp. 1-14

Author(s):

Ceridwen R. Radcliffe ◽

Celeste E. Coltman ◽

Wayne A. Spratford

Keyword(s):

Achilles Tendon ◽

Tendon Force

Download Full-text

Mechanotendography in Achillodynia shows reduced oscillation variability of pre-loaded Achilles tendon: a pilot study

European Journal of Translational Myology ◽

10.4081/ejtm.2020.8983 ◽

2020 ◽

Vol 30 (2) ◽

pp. 247-257

Author(s):

Laura Schaefer ◽

Frank Bittmann

Keyword(s):

Achilles Tendon ◽

Rank Correlation ◽

Achilles Tendinopathy ◽

The Body ◽

Mechanical Pressure ◽

Mechanical Oscillations ◽

Pressure Impact ◽

The Subject ◽

The Mean ◽

Intrapersonal Variability

The present study focuses on an innovative approach in measuring the mechanical oscillations of pre-loaded Achilles tendon by using Mechanotendography (MTG) during application of a short yet powerful mechanical pressure impact. This was applied on the forefoot from the plantar side in direction of dorsiflexion, while the subject stood on the ball of the forefoot on one leg. Participants with Achilles tendinopathy (AT; n = 10) were compared to healthy controls (Con; n = 10). Five trials were performed on each side of the body. For evaluation, two intervals after the impulse began (0-100ms; 30-100ms) were cut from the MTG and pressure raw signals. The intrapersonal variability between the five trials in both intervals were evaluated using the arithmetic mean and coefficient of variation of the mean correlation (Spearman rank correlation) and the normalized averaged mean distances, respectively. The AT-group showed a significantly reduced variability in MTG compared to the Con-group (from p = 0.006 to p = 0.028 for different parameters). The 95% confidence intervals (CI) of MTG results were disjoint, whereas the 95% CIs of the pressure signals were similar (p = 0.192 to p = 0.601). We suggest from this work that the variability of mechanical tendon oscillations could be an indicative parameter of an altered Achilles tendon functionality.

Download Full-text

Quantification of Achilles Tendon Force Enhancement by Passively Induced Dorsiflexion Stretches

Journal of Applied Biomechanics ◽

10.1123/jab.15.3.221 ◽

1999 ◽

Vol 15 (3) ◽

pp. 221-232 ◽

Cited By ~ 6

Author(s):

Caroline Nicol ◽

Paavo V. Komi

Keyword(s):

Achilles Tendon ◽

Female Subject ◽

Plateau Phase ◽

Force Enhancement ◽

Surface Electrodes ◽

Twitch Response ◽

Tendon Force ◽

The Right ◽

Passive Stretch

Magnitude of the reflex contribution to force enhancement was investigated in vivo during passive stretches of the Achilles tendon (AT) of one female subject. Thirty passive (5 × 6) dorsiflexions were induced by a motorized ankle ergometer. Achilles tendon force (ATF) was sensed by a buckle transducer applied surgically around the right AT. Single passive stretches resulted in a low but rather linear ATF increase in the absence of EMG (surface electrodes) activity. In the presence of reflexes, a clear ATF enhancement occurred 13–15 ms after the beginning of the EMG reflex responses. In double dorsiflexions at either 1.2 or 1.9 rad · s-1, which were separated by a maintained stretched position of either 40 or 90 ms, the first stretch resulted in initial linear ATF increase, followed by an additional force enhancement during the plateau phase. This reflexly induced increase represented 94 ± 4 N and 184 ± 1 N, respectively, for the 40 and the 90 ms plateaus, corresponding to 210 ± 85% and 486 ± 177% enhancements as compared to the first passive stretch effect. The results suggest further that timing of the stretch during the twitch response influences the magnitude and rate of force potentiation.

Download Full-text

Continued Sports Activity, Using a Pain-Monitoring Model, during Rehabilitation in Patients with Achilles Tendinopathy

The American Journal of Sports Medicine ◽

10.1177/0363546506298279 ◽

2007 ◽

Vol 35 (6) ◽

pp. 897-906 ◽

Cited By ~ 138

Author(s):

Karin Grävare Silbernagel ◽

Roland Thomeé ◽

Bengt I. Eriksson ◽

Jon Karlsson

Keyword(s):

Standard Deviation ◽

Exercise Training ◽

Achilles Tendon ◽

Primary Outcome ◽

Initial Period ◽

Treatment Protocol ◽

Training Group ◽

Achilles Tendinopathy ◽

Monitoring Model

Background Achilles tendinopathy is a common overuse injury, especially among athletes involved in activities that include running and jumping. Often an initial period of rest from the pain-provoking activity is recommended. Purpose To prospectively evaluate if continued running and jumping during treatment with an Achilles tendon-loading strengthening program has an effect on the outcome. Study Design Randomized clinical control trial; Level of evidence, 1. Methods Thirty-eight patients with Achilles tendinopathy were randomly allocated to 2 different treatment groups. The exercise training group (n = 19) was allowed, with the use of a pain-monitoring model, to continue Achilles tendon-loading activity, such as running and jumping, whereas the active rest group (n = 19) had to stop such activities during the first 6 weeks. All patients were rehabilitated according to an identical rehabilitation program. The primary outcome measures were the Swedish version of the Victorian Institute of Sports Assessment—Achilles questionnaire (VISA-A-S) and the pain level during tendon-loading activity. Results No significant differences in the rate of improvements were found between the groups. Both groups showed, however, significant (P < .01) improvements, compared with baseline, on the primary outcome measure at all the evaluations. The exercise training group had a mean (standard deviation) VISA-A-S score of 57 (15.8) at baseline and 85 (12.7) at the 12-month follow-up (P < .01). The active rest group had a mean (standard deviation) VISA-A-S score of 57 (15.7) at baseline and 91 (8.2) at the 12-month follow-up (P < .01). Conclusions No negative effects could be demonstrated from continuing Achilles tendon-loading activity, such as running and jumping, with the use of a pain-monitoring model, during treatment. Our treatment protocol for patients with Achilles tendinopathy, which gradually increases the load on the Achilles tendon and calf muscle, demonstrated significant improvements. A training regimen of continued, pain-monitored, tendon-loading physical activity might therefore represent a valuable option for patients with Achilles tendinopathy.

Download Full-text

Novel Physical Therapy Protocol Targeting Insertional Achilles Tendinopathy Improves Patient Reported Outcomes that Persist For 1 Year

Foot & Ankle Orthopaedics ◽

10.1177/2473011418s00284 ◽

2018 ◽

Vol 3 (3) ◽

pp. 2473011418S0028

Author(s):

Meghan Kelly ◽

Ashlee MacDonald ◽

Rachel Olson ◽

Grace Weyand ◽

Ruth Chimenti ◽

...

Keyword(s):

Physical Therapy ◽

Achilles Tendon ◽

Exercise Program ◽

Achilles Tendinopathy ◽

Home Exercise ◽

Sf 36 ◽

Patient Reported ◽

One Year ◽

Therapy Protocol

Category: Sports Introduction/Purpose: Insertional Achilles Tendinopathy (IAT) affects 5% of the general population and up to 20% of the athletic population. Despite trials of non-surgical management such as physical therapy and heels lifts, more than 50% of patients ultimately pursue surgery. One hypothesis regarding the development of IAT pain and stiffness is that ankle dorsiflexion and associated calcaneal impingement causes transverse compression of the tendon insertion, inducing metaplastic changes within the Achilles tendon, and bursa, contributing to inflammation. Thus the aim of the current study is to examine the effect of a home exercise program designed to minimize compression of insertional tissues for patients with IAT on patient reported outcomes (PRO) measures at 3 months and one year. Methods: Thirty-five patients with IAT were enrolled in the study from May 2014 until June 2015 as two separate cohorts (21 and 14 patients, respectively) of whom 26 completed the study (mean age: 56.7 + 10.1 years, BMI: 29.5 + 6.0 kg/m2, 58% women). One patient elected for surgery prior to completing the physical therapy protocol. Physical therapy exercises were progressive eccentric loading of the Achilles tendon and seated isometric plantar flexion that were performed 4 times a week for 3 months. The Victorian Institute of Sport Assessment – Achilles (VISA-A), the Foot and Ankle Ability Measure (FAAM) and the SF-36 questionnaires were completed at baseline and at the completion of the 3-month physical therapy protocol. Six of the 14 patients in the second cohort returned for a 1 year follow up visit; four patients were lost to follow up and 4 had undergone surgical intervention prior to 1-year follow up. Results: Completion of the 3 month protocol resulted in statistically significant improvements in VISA-A, FAAM ADL and sports scores as well as multiple subcategories of the SF-36 (physical function, role limiting physical function, energy/vitality, social functioning and general pain). Twenty-two of the 26 patients (~85%) that completed the study had clinically significant, greater than MCID, improvements in their VISA-A and/or FAAM scores. In the second cohort, all six patients that returned for a one year follow up assessment maintained their improved VISA-A and FAAM scores observed at the end of the initial physical therapy protocol. Of the four patients that underwent surgical intervention prior to follow up, two did not demonstrate improvement in any of their outcomes following the initial study period. Conclusion: The results of the present study suggest that a physical therapy home exercise program utilizing eccentric and isometric Achilles exercises may result in a greater improvement in functional outcomes compared to other exercise programs that do not progressively increase both ankle dorsiflexion and Achilles tendon loading. Furthermore, improvements in pain and function result in increased energy and social wellbeing. Finally, symptomatic improvement that occurs after 3 months is likely to persist for at least one year following initial treatment.

Download Full-text

The Addition of a Krackow Rip Stop Suture Augment After Achilles Tendon Debridement for Insertional Achilles Tendinopathy: A Biomechanical Study

Foot & Ankle Specialist ◽

10.1177/19386400211033693 ◽

2021 ◽

pp. 193864002110336

Author(s):

LT Thomas J. Kelsey ◽

LT Kyle W. Mombell ◽

CDR Todd A. Fellars

Keyword(s):

Achilles Tendon ◽

Suture Anchor ◽

Maximum Load ◽

Achilles Tendinopathy ◽

Catastrophic Failure ◽

Double Row ◽

Average Load ◽

Load To Failure ◽

Insertional Achilles Tendinopathy ◽

Repair Techniques

Background In the operative treatment of insertional Achilles tendinopathy, the Achilles tendon is often released from its insertion to allow for adequate debridement of pathologic tissue. The use of a double row suture anchor construct has become increasingly favorable among surgeons after Achilles tendon debridement. This study hypothesized that the addition of a Krackow rip stop suture augment to the double row suture anchor construct would increase the repair’s maximum load to failure. A biomechanically stronger repair would potentially decrease the risk of catastrophic failure with early weight-bearing or accidental forced dorsiflexion after operative management for insertional Achilles tendinopathy. Methods Fourteen cadaveric specimens were used to compare the 2 repair techniques. Achilles tendons were debrided and repaired using either a double row suture anchor with and without the additional Krackow rip stop suture augment. The 2 repair techniques were compared using an axial-torsion testing system to measure average load to failure. Results The average load to failure for the double row suture anchor repair alone was 152.00 N. The average load to failure for the tendons with the double row suture anchor with the Krackow rip stop augment was 383.08 N. An independent-samples Mann-Whitney U-test was conducted and the suture anchor plus Krackow augment group had a significantly higher load to failure ( P = .011, Mann-Whitney U = 5.00, n1 = n2 = 7, P < .05, 2-tailed). Conclusion This study confirmed that the addition of a Krakow rip stop augment to the double row suture anchor is able to increase the maximum load to failure when compared to the double row suture anchor alone. These results suggest the potential of this added technique to decrease the risk of catastrophic failure.

Download Full-text

Tendon Morphology and Mechanical Properties Are Associated With the Recovery of Symptoms and Function in Patients With Achilles Tendinopathy

Orthopaedic Journal of Sports Medicine ◽

10.1177/2325967120917271 ◽

2020 ◽

Vol 8 (4) ◽

pp. 232596712091727

Author(s):

Patrick Corrigan ◽

Daniel H. Cortes ◽

Ryan T. Pohlig ◽

Karin Grävare Silbernagel

Keyword(s):

Mechanical Properties ◽

Shear Modulus ◽

Achilles Tendon ◽

Achilles Tendinopathy ◽

Calf Muscle ◽

Initial Assessment ◽

Muscle Endurance ◽

Patient Reported ◽

Morphology And Mechanical Properties

Background: Achilles tendinopathy is a debilitating overuse injury characterized by pain, altered Achilles tendon structure, and impaired functional performance. Evaluating tendon structure as part of the physical examination may help establish a well-defined prognosis. However, the usefulness of measuring tendon structure for developing a prognosis has been questioned since structural abnormalities can exist without symptoms. Purpose: To determine whether initial measures of tendon morphology and mechanical properties were associated with patient-reported symptoms and calf muscle endurance at baseline, 6-month follow-up, and 1-year follow-up by prospectively following a cohort of individuals with Achilles tendinopathy. Study Design: Cohort study; Level of evidence, 2. Methods: A total of 59 participants with midportion or insertional Achilles tendinopathy completed an initial assessment and follow-up assessments at 6 months and 1 year. At the initial assessment, patient-reported symptoms, calf muscle endurance, and Achilles tendon thickening were evaluated, and Achilles tendon mechanical properties were estimated. At the 6-month and 1-year follow-up assessments, patient-reported symptoms and calf muscle endurance were reevaluated. Results: Greater Achilles tendon thickening at the initial assessment was consistently associated with worse patient-reported symptoms and calf muscle endurance at each assessment. Changes in symptoms over the year were moderated by the initial shear modulus of the tendon, with a lower shear modulus associated with less improvement in symptoms. Lower viscosity at the initial assessment was also associated with worse calf muscle endurance at each assessment. Conclusion: Measures of tendon morphology and mechanical properties appear to be associated with patient-reported symptoms and calf muscle function for patients with Achilles tendinopathy.

Download Full-text