Review of Most Effective Tendon Loading Regimen for Treatment of Non-Insertional Chronic Midsubstance Achilles Tendinopathy

1. Review of Most Effective Tendon
Loading Regimen for Treatment of
Non-Insertional Chronic
Midsubstance Achilles Tendinopathy
Lauren Jarmusz, PT, DPT
Orthopedic Physical Therapy Resident
Orthopedic and Sports Medicine - Physical Therapy Department
Stanford Healthcare
July 12th, 2017

2. PICO Question
Population:
Recreational Athletes with Chronic
Midsubstance Achilles Tendinopathy
Intervention & Comparison:
Eccentric vs. Combined vs. Stretching
Tendon Loading Programs
Outcome:
Effect on VAS & VISA-A Scores

3. Introduction
1.Chronic Midsubstance Achilles Tendinopathy
2.Etiology & Epidemiology
3.History of Tendon Loading Programs

5. Etiology & Epidemiology
INTRINSIC FACTORS
 Watershed Region (zone of hypo-vascularity)1,2,3
 Gastroc-Soleus Dysfunction (muscle length
restriction OR weakness)4,5,6
 Excessive RF motion in frontal plane/ “whipping
action” 7
Neurovascular Ingrowth 1,2,3
Extracellular Matrix Disorganization 1,2,3
Obesity, HTN, DM, hyperlipidemia 8
Men > Women
EXTRINSIC FACTORS
 Excessive tensile & compressive loads
secondary to overtraining/overuse OR
rapid change in training schedule 1,2,3
Use of fluoroquinolones and
corticosteroids9,10
Runners 11,12

6. Reactive Dysrepair Degeneration
• Non-inflammatory cell
response
• metaplastic change in the cells
and cell proliferation
• No change in neurovascular
structures
IMAGING :
• Increase in diameter
• no/minimal increased signal
CLINICAL :
• Acutely overloaded tendon
• Tendons chronically exposed to
low levels of load (detrained
athlete returning from injury)
• Same as reactive
• matrix breakdown
• Increase in vascularity and
neuronal ingrowth
IMAGING:
• increased matrix disorganization
• Increase in diameter
• increased signal
CLINICAL:
• Thick tendon with localized
changes in one area of tendon
• Older pt’s may develop with
lower loads
• Significant matrix breakdown
• cellular death
• Filled with vessels and neuronal ingrowth
• Little capacity for reversibility
IMAGING:
• Significant hypoechoic regions
• Numerous and larger vessels present
• Increase in diameter
CLINICAL:
• Chronically overloaded tendon
• 1+ focal nodule areas with or without
thickening
• Hx: repeated bouts of tendon pain, resolved,
but returning as tendon load changes.
• Rupture possible
(Cook & Purdam, 2009)

7. Sources of Pain
2 Categories 1,2
1. reactive tendon following acute
overload
2. reactive-on-late
dysrepair/degenerative tendon
pathology.
Nociceptive driver in tendinopathy
debated3
 Reactive or reactive-on-
degenerative tendon may
increase expression of
nociceptive substances and their
receptors, stimulating the
peripheral nerve and be
interpreted as pain.
 Irritation the peritendon may be
due increase in tendon size
 Hypervascularity and neuronal
growth

8. Midsubstance Achilles Tendinopathy
Direct palpation:
(+) Achilles tendon 4 cm proximal to
distal insertion (84% specificity, 58%
sensitivity)
Arc Test (+) (83% specificity, 52% sensitivity)
Royal London Hospital Test (+) (91%
specificity,54% sensitivity)
All 3 previous tests for Achilles
tendinopathy combined = 83% specificity,
58% sensitivity 13

9. History of Tendon Loading Programs
Stanish ’86
Alfredson
Eccentric
Loading ’98
Combined
Tendon Loading
‘Present

10. Search
1.Sources; Key Words & Phrases
2.Inclusion & Exclusion Criteria
3.Summary

11. Sources
1. achilles tendinopathy AND physical therapy
2. achilles tendinopathy AND tendon loading
3. achilles tendinopathy AND conservative treatment
4. achilles tendinopathy AND eccentric
5. achilles tendinopathy AND concentric
6. achilles tendinopathy AND non-operative treatment
Key Words & Phrases

12. Study Selection Criteria
INCLUSION CRITERIA
1. Studies investigating clinical outcomes of loading
programs in achilles tendinopathy. Programs
must consist of musculotendon loading including:
eccentric, concentric, isometric, combined
loading programs, and/or stretching.
2. Randomized Controlled Trials, Controlled Clinical
Trials, Case Series
3. Recreational Athletes
4. Dx Non-Insertional Achilles Tendinopathy
5. Symptoms > 3 Months
6. Use of VAS or VISA-A Outcome Measure
EXCLUSION CRITERIA
1. Symptoms < 3 Months
2. Sedentary Individuals
3. Studies comparing tendon loading programs to
surgical interventions or other non-operative
treatments which did not include tendon loading
program
4. Location of tendinopathy unknown, or insertional
tendinopathy
5. Comorbidities such as retrocalcaneal bursitis,
Haglund’s syndrome, or rheumatological/vascular
diseases.

13. PubMed Scopus CINHAL
Achilles tendinopathy AND
physical therapy
281 2642 53
Achilles tendinopathy AND
tendon loading program
11 492 1
Achilles tendinopathy AND
conservative treatment
143 1140 19
Achilles tendinopathy AND
eccentric
201 1794 116
Achilles tendinopathy AND
concentric
28 566 13
Total Studies Selected: 7

14. Summary of Data
1. Methodological Quality Assessment
2. Methodology & Reliability of Tools
3. Subject Characteristics
4. Overview of Studies

15. Methodological Quality Assessment of Included Studies
Study (year)* Criteria
1** 2 3 4 5 6 7 8 9 10 11 Total
Score
Rompe et al. 2007 + + + + - - + + + + + 8/10
Stasinopoulos et al.
2013
+ - - + - - + + + + + 6/10
Mafi et al. 2001 + + - + - - - + + + - 5/10
Stevens et al. 2014 + + + + - - + - + + + 7/10
Beyer et al. 2015 + + - + - - - - + + + 5/10
Silbernagel et al.
2001
+ + - + - - + - - + + 5/10
Methodological Quality Assessment of
Included Studies
(PEDRO & Quality Assessment Tool for Case Series Studies from the NIH)

16. VISA- A14
 Objective: evaluate the clinical severity for patients with chronic
Achilles tendinopathy
 Administration: 8 questions, covering 3 domains: (1) pain (2)
functional status (3) activity
 Score: max score = 100. A recreational person with Achilles
tendinopathy will not score higher than 70/100
 Reliability: intrarater (r = 0.90), and interrater (r=0.90)
 Validity: correlates significantly with both Percy and Conochie’s
grade of severity (Spearman’s r =0.58; p<0.01) and Curwin and
Stanish (Spearman’s r=-0.57; p<0.001).
 MCID: 10 points

17. VAS Pain Score15,16
OBJECTIVE:
unidimensional measure of pain intensity
ADMINISTRATION:
Straight horizontal or vertical line (100 mm.) The ends are
defined as the extreme limits of the parameter to be measured
(symptom,pain,health)
SCORE:
Using a ruler, the score is determined by measuring the
distance (mm): no pain (0–4 mm), mild pain (5–44
RELIABILITY: Test-Retest (r= 0.94, P= 0.001)
CONSTRUCT VALIDITY: correlations ranging from 0.71–0.78
MCID: 33% decrease in pain level ~ 1.37cm

18. The studies selected investigated a total of 379 patients. Mean age of participates in the
selected studies was 47.8 years. Participants were both male and female and were
considered recreational athletes. All participants included had been diagnosed with
chronic (>3months of symptoms) achilles tendinopathy.
Diagnosis of chronic
midportion achilles
tendinopathy: ultrasound
tissue changes, tenderness to
palpation, special testing,
subjective reports.

19. Study Design:
Randomized Controlled Trial
Sample Size (n): 58
Interventions:
1. Heavy Slow Resistance
2. Alfredson Protocol
Improvement on VAS &
VISA-A Scores:
Heavy Slow Resistance >
Alfredson Protocol

20. Study Design:
Case Series
Sample Size (n): 44
Interventions:
1. Progressive Eccentric
Tendon Loading
Improvement on VISA-A
Scores:
Effective in Improving
VISA-A Score

21. Study Design
Randomized Controlled Trial
Sample Size (n): 44
Interventions:
1. Alfredson Protocol
2. Combined (Concentric)
Improvement on VAS
Scores:
Alfredson Protocol >
Combined (Concentric)

22. Study Design
Randomized Controlled Trial
Sample Size (n): 75
Interventions:
1. Modified Alfredson
Protocol
2. Wait and See (Stretching)
Improvement on VISA-A
Scores:
Modified Alfredson Protocol
> Wait and See (Stretching)

23. Study Design
Randomized Controlled Trial
Sample Size (n): 44
Interventions:
1. High Intensity Combined
Tendon Loading Program
2. Low Intensity Combined
Tendon Loading Program
Improvement on VAS
Scores:
High Intensity > Low Intensity

24. Study Design:
Control Clinical Trial
Sample Size (n): 41
Interventions:
1. Alfredson Protocol
2. Stanish Protocol
Improvement on VISA-A
Scores:
Alfredson Protocol > Stanish
Protocol

25. Study Design:
Randomized Controlled Trial
Sample Size (n): 28
Intervention:
1. Alfredson Protocol
2. “Do as Tolerated”
Alfredson Protocol
Improvement on VAS &
VISA-A Scores:
Alfredson Protocol = “Do as
Tolerated” Alfredson
Protocol

26. Discussion
1. Tendon Loading (RM, Weight)
2. Tendon Loading Time
3. Stretching &Pain
4. Medications

27. Tendon Loading Pathophysiology
 Tendon cells, fibroblasts, respond to mechanical stimuli in the form of Strain 17,18,19
 Strain is the response of a system to an applied stress. When a material is loaded with a force,
it produces a stress, which then causes a material to deform
 Strain magnitude needed to remodel tendon tissue is not well established. In healthy human
Achilles tendons, it has been shown that working at 90% of MVC, results in approximately 5% of
tendon strain, results in increased stiffness, and cross-sectional area, compared to working at
55% MVC, which only causes approximately 3% tendon strain 17,20
 Definitions of “concentric” and “eccentric” solely apply to a muscle, unlike a tendon, which is a
mechanically passive structure that lengthens when load increases and shortens when load is
reduced.
 Primary reason for the greater mechanical stimulation from eccentric exercises vs concentric
exercise is because muscles can produce greater maximal force eccentrically than
concentrically17,21

28. Farup et al 2014: Tendon and Muscle Hypertrophy
Independent of Resistance Exercise Contraction Mode22
 Objective: Effect of contraction mode on tendon and muscle hypertrophy in 22
healthy human subjects was examined.
 12 week resistance training consisted of isolated concentric knee extensions
on one side and eccentric knee extensions on the contralateral side.
 Sets, repetitions, and time of load were similar between sides, but the loading
for the eccentric side was 120% of the concentric side.
 Results: showed that resistance training with either concentric or eccentric
contraction produced similar magnitude of tendon hypertrophy, reinforcing the
notion that the cellular and tissue response in healthy tendon is independent of
contraction mode.

29. Traditional AEP vs “Do as Tolerated” AEP23
AEP, requires a high frequency of repetitions of the exercise AND progressively loads the
patients over a time span of 12 weeks.
“Do-as-Tolerated” AEP vs traditional AEP: No significant difference between both the VISA-
A and VAS scores.
One constant factor between the “Do as Tolerated” AEP protocol and the traditional AEP:
tendon loading was consistent, allowing us to draw the inference that the progressive
tendon loading takes higher priority over frequency and number of repetitions of exercise.

30. Alfredson vs Heavy Slow Resistance24
 HSR program proved to be more effective in improving VISA-A sores and decreasing VAS
scores.
 HSR protocol completed 3 times per week vs AEP completed daily (3x15 2x/day)
 HSR protocol more aggressively loaded patient: decreasing reps and increasing load as the
patient progressed.
 Weeks 9 through 12 of HSR protocol, patients were working at their 6RM rate, compared to the
AEP with simply stated “progressively ad weight to backpack.”
 AEP < HSR

31. Progressive Eccentric Tendon Loading
(Maffulli 25)vs HSR & AEP (Beyer24)
 Maffulli: participants were instructed to complete a modified AEP which included increased speed of
contraction along with progressive loading.
 Maffulli: “When the exercise could be completed with no pain or discomfort, they progressed to use a rucksack
with 5 kg of books. They were invited to continue to add weight in multiples of 5 kg if they did not experience
pain in the Achilles tendon by the end of the third set of the eccentric exercises.”
 VISA-A scores significantly increased following the modified Maffulli AEP protocol, and were equal to the
improvement of those completing the AEP in the Beyer study, however, the VISA-A score improvement was still
less than the improvement shown by the HSR program.
 Maffulli AEP = Traditional AEP < HSR

32. Low/High Intensity Tendon Loading
(Silbernagel) vs AEP & HSR (Beyer)
 Both “low intensity” and “high intensity” tendon loading programs underperformed when
compared to both the traditional AEP and the HSR program in decreasing VAS scores with
activity.
 Neither the high intensity nor low intensity program progressively loaded their subjects.
 Primary difference between the two groups: “high intensity” group performed more exercises,
reps, and sets than the “low intensity” group.
 “High intensity” vs “low intensity group” “high intensity group” only slightly outperformed
the “low intensity group”, but both groups underperformed in comparison to the AEP and HSR
protocol.
 High/Low Intensity < AEP < HSR

33. Combined Loading Program vs AEP (Mafi26)
 Conclusion: Eccentric loading (AEP) was more effective than combined tendon loading program.
 Both the combined tendon loading program and the eccentric tendon loading programs resulted in
significant (MCID) improvements in VAS score with walking or running. However there was a
substantial difference in the number of patients with significantly improved VAS scores. 18 of 22
participants in the eccentric tendon loading program and only 8 of 22 participants in the combined
tendon loading programs experienced significant improvements in VAS score.
 Limitation: Combined tendon loading program was not progressively loaded - exercises progressed in
respect to weight bearing, position, and speed, but a progressive load was not added to the exercise.

34. Tendon Time Under Tension
 Speed and/or duration of loading during exercise is needed for tendon
remodeling 17,19, 27,28
Tendon extracellular matrix (ECM) is viscoelastic in origin
 slower loading regime results in increased creep allowing for tendon
remodeling of ECM 29
 Viscoelastic behavior depends on the amount of time the tendon is under
load not the type of muscular contraction (eccentric or concentric)17
 Remodeling of the Achilles tendon is more responsive to a low number of
loads of long duration (6 second cycle) compared to high number of faster
loads (2 second cycle) 17 , 27, 30
 Study for treatment of patella tendinopathy: comparing efficacy of
isolated eccentric squats to mixed concentric/eccentric heavy slow
resistance training, the results stated that both interventions reduced pain
and improved function, but increased collagen content and reduced
glycation were only evident with heavy slow resistance training 17, 31

35. Tendon Time Under Tension
 One study took the time of tendon loading time into account.
 Beyer Protocol24 stated “All exercises were performed in the full range of motion of the ankle
joint, and patients were instructed to spend 3 seconds completing each eccentric and
concentric phase (ie, 6 seconds per repetition)”.
 This specific clarification of tendon loading time is another reason why the HSR protocol was
extremely successful in improving VISA-A scores and reducing VAS pain scores.
 Although ECM remodeling may be better accomplished with slower loading regimes, it is
important to acknowledge that quick reactive speeds, quick concentric and eccentric loading,
not only improve tendon stiffness1,23,32,22 but it is also imperative to train a tendon in the
environment it will be utilized in.
 i.e runners, are going to require an achilles tenon that can withstand “quick” concentric and
eccentric loading, and therefore the incorporation of quick tendon loading should be
incorporated into return to sport training33,34

36. Pain Level & Stretching
 Fine line in determining the appropriate frequency and load of tendon remodeling protocols so
as not to exacerbate tendon causing a relapse into an acute phase Achilles tendinopathy and
experiencing enough load/pain to effectively remodel ECM2
 If Patient is experiencing significant pain, he/she may resort to taking NSAIDs, which is known
to inhibit tendon proliferation/ tendon remodeling and retard soft tissue healing in tissues2,36
The frequency of the Alfredson Protocol is twice daily, however, per reviewing the literature,
the anabolic response to tendon loading is sustained in a tendon for up to 72 hours following
an exercise bout17,33,37
 Need for post exercise recovery period may be indicated if the patient is in significant pain.
This concept supports the effectiveness of the HSR protocol considering that it was only
completed 3x/week to allow for tendon recovery time.

37. Rompe et al. “Wait & See” Approach-
Rest, Stretching, NSAIDs vs AEP38
 AEP vs “wait and see” approach, which included rest from “training” (training modification),
NSAIDs, and stretching.
 Results: “wait and see” approach was ineffective in improving function and improving VISA-A
scores
 Excessive stretching, prolonged rest/ reduced tendon loading, and use of NSAIDs are all
detrimental to tendon ECM remodeling ultimately inhibiting improved function and decreased
pain.

38. Effects of Pain
ALLOWED CONTROLLED PAIN
 Alfredson Protocol: Beyer, Maffulli,
Mafi, Rompe, Stasinopoulous, Stevens
 Combined Protocols: Mafi
 Heavy Slow Resistance: Beyer
 High Intensity Combined:
Silbernagel
DID NOT ALLOW CONTROLLED PAIN
 Stretching/ Activity
Modification: Rompe
 Stanish: Stasinopoulous (pain only in last
10 reps)
 Low Intensity Combined:
Silbernagel
Alfredson Pain Protocol:
“Patients were told to go ahead with the exercise even if they experienced pain. However, they
were told to stop the exercise if the pain became disabling.”
 Mafi (Combined Tendon Loading)
 Beyer (HSR)
Pain Monitoring Model (Thomee 1997) – Silbernagel (High Intensity):
1. The pain was allowed to reach 5 on the VAS during the
exercises, if the pain decreased immediately after the end of
the exercise.
2. The pain after the whole exercise program was allowed to
reach 5 on the VAS but should have subsided the following
morning.
3. Pain and stiffness in the Achilles tendon was not allowed to
increase from day to day.
Silberngel Low Intensity Pain Protocol:
“ The exercise programme was not allowed to cause pain or make
the symptoms worse, and if this happened the patients were
asked to decrease the training intensity.”
Stanish Pain Protocol:
“The intensity of the exercise should be such that pain, or discomfort,
was experienced in the last set of 10 repetitions.”

39. Outcomes of Controlled Pain
Protocols which allowed for controlled pain experienced
better VISA-A and VAS outcomes than protocols which did
not allow for controlled pain.

40. VISA-A: 0 weeks VISA-A: 12 weeks VISA-A Change VAS: 0 Weeks VAS: 12 Weeks VAS Change
Rompe et al. 2007
Modified Alfredson 50 75 25*
Stretching 48 55 7
Stasinopoulos et al. 2013
Stanish Protocol 38 63 25x
Alfredson Protocol 36 76 40x
Mafi et al. 2001***
Alfredson Protocol 69 12 57*
Combined 63 9 54*
Stevens et al. 2014
Alfredson Protocol 50 41 9 52 51 9
Alfredson Do-As-Tolerated 47 56 9 55 47 9
Beyer et al. 2015*
The Alfredson Protocol 58 72 14x Running: 49
Heel Rise: 19
Running: 20
Heel Rise: 12
Running: 29x
Heel Rise: 7
Heavy Slow Resistance 54 76 22x Running: 54
Heel Rise: 29
Running: 17
Heel Rise: 7
Running: 37x
Heel Rise: 22x
Silbernagel et al. 2001*
Low Intensity Combined Activity: 15
Walking: 13
Activity: 10
Walking: 9
Activity: 5
Walking: 4
High Intensity Combined Activity: 23
Walking: 15
Activity: 15
Walking: 11
Activity: 8
Walking: 4
Maffulli et al. 2008 **
Progressive Eccentric Loading 36 52 16x

41. Conclusion Points
1.Tendon Loading Time: 6s loading TUT
2.Training Specificity:
• 55-90% MVC
• 6RM wks 9-12
• slow and quick tendon loading training
3. Patient Compliance: 3x/week
4. Allow for Controlled Pain
5. Avoid use of NSAIDs

42. Conclusion Equation
Stretching/ Rest/NSAIDs < High or low repetition
exercises without progressive loading < Alfredson
Eccentric Tendon Loading Program = Combined
Tendon Loading Program with Progressions (speed,
positioning) < Heavy Load Slow Resistance Tendon
Loading Program

43. Conclusion
The most effective tendon loading program for the treatment of
chronic midsubstance Achilles tendinopathy for recreational
athletes by improving VISA-A & VAS scores and taking into
account: compliance, pain management, and return to activity
training is a:
heavy slow resistance tendon loading program, with associated
quick tendon loading intervals, completed 3x/week, allowing
for controlled pain and avoiding use of NSAIDs

44. Clinical Application: Best Published
Tendon Loading Program

45. Clinical Application:
Best Published Tendon
Loading Program

46. Literature Review Limitations
Similar but not completely homogenous subject characteristics
utilized in studies
 Heterogeneous exercise protocols & definition of “concentric”,
“eccentric”, “stretching”, “combined exercise programs
 Unknown effects of cross training while completing exercise
protocols
 Differing supervision when completing HEP
 VAS comparison between heterogenous activities

47. Future Research
 Comparison between combined tendon loading protcols
with homogeneous protocol style: freq, sets, reps, speed, time
under tension, cross-training, allowance for pain
 Need to correct biomechanical movement impairments (ie:
gastroc/soleus length, proximal hip strength) prior to
initiation of tendon loading program.

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