Achilles Tendinopathy: Heavy Slow Resistance (HSR) vs Alfredson Eccentric Loading
In short
Midportion Achilles tendinopathy limits runners and walkers. Compare the Alfredson eccentric protocol with Heavy Slow Resistance (HSR), VISA-A scoring, and loading progressions.
In this guide (5 sections)
Anatomy and Clinical Presentation of Midportion Achilles Tendinopathy
The Achilles tendon is the largest and strongest tendon in the human body, transmitting forces up to 8 to 10 times body weight during sprinting and jumping.
Midportion Achilles tendinopathy occurs 2 to 6 cm proximal to the calcaneal insertion, in an area of relatively low vascularity (watershed zone), characterized by localized tendon thickening, morning stiffness that eases with light walking, and pain during explosive push-off.
It is critically distinct from insertional Achilles tendinopathy, which occurs directly at the bone-tendon junction on the calcaneus and is aggravated by deep dorsiflexion compression.
Alfredson Eccentric Heel Drops vs Heavy Slow Resistance (HSR)
Two validated exercise paradigms dominate the clinical literature: the traditional Alfredson protocol and the modern Heavy Slow Resistance (HSR) protocol developed by Kongsgaard and colleagues.
| Protocol Parameter | Alfredson Eccentric Protocol (1998) | Heavy Slow Resistance (HSR, 2009) | Clinical Evidence & Adherence | |
|---|---|---|---|---|
| 1. Loading Type | Isolated eccentric heel drop off step edge | Both concentric lifting (3s) and eccentric lowering (3s) | HSR stimulates both collagen synthesis and muscle hypertrophy. | |
| 2. Repetition Volume | 180 repetitions DAILY (3 sets of 15 straight and bent knee, 2x/day) | 3 to 4 sets of 6 to 8 repetitions, 3 DAYS PER WEEK | HSR requires 80% less weekly time; significantly higher patient adherence. | |
| 3. External Load | Bodyweight progressing with weighted backpack | Calibrated machine weights (leg press, calf raise) at 70-85% 1RM | HSR applies controlled, high-magnitude mechanical strain. | |
| 4. Patient Satisfaction | High clinical success (~70%), but high dropout rate due to soreness | Equal or superior clinical success with higher patient satisfaction | HSR preferred by active runners and athletes. |
The Victorian Institute of Sport Assessment (VISA-A) Score
The VISA-A questionnaire is the international gold standard clinical outcome measure for Achilles tendinopathy, scoring pain, function, and sports participation from 0 (complete disability) to 100 (asymptomatic elite athletic function).
- Isometric Analgesic Loading (Phase 1): Perform straight-leg and bent-knee calf holds on a flat floor: 5 sets of 45 seconds holding near maximal height with a weighted vest, providing rapid pain inhibition.
- Isotonic HSR Progression (Phase 2): Seated soleus calf raises and standing gastrocnemius calf raises on a flat surface, 4 sets of 8 reps taking 3 seconds up and 3 seconds down, performed 3 days weekly.
- Energy Storage Re-Training (Phase 3): Introduce double-leg jump roping, two-legged pogo hops, and single-leg hopping when single heel raises are pain-free with heavy loads.
- Insertional Achilles Modification: For insertional tendinopathy, perform all heel raises strictly on a FLAT floor, NEVER dropping the heel below the step level, which causes compressive impingement against the calcaneal tuberosity.
Footwear and Heel Lift Adaptations in India
Walking barefoot on hard marble floors in Indian households increases Achilles tensile and dorsiflexion strain. Placing a temporary 10 to 12 mm silicone heel lift inside closed supportive shoes immediately reduces tendon excursion and resting strain.
Physiotherapists instruct runners on gradual return-to-running intervals (walk-run ratios), avoiding speed work and hill climbs during the first 6 weeks.
Frequently Asked Questions
How long does Achilles tendinopathy take to resolve?
Tendon tissue remodels slowly. Most patients require 12 to 24 weeks of consistent heavy slow resistance training to achieve pain-free sports return and normalized VISA-A scores.
Can I continue running while recovering from Achilles tendinopathy?
Yes, provided running pain does not exceed 3 to 4 out of 10 and morning stiffness the next day lasts less than 15 minutes. High-speed sprinting and hill running must be paused until plyometric capacity is restored.
What is the difference between midportion and insertional Achilles pain?
Midportion pain is located 2 to 6 cm above the heel in the main tendon body and benefits from heel drops off a step. Insertional pain occurs directly where the tendon attaches to the heel bone; dropping the heel off a step compresses the tendon and worsens symptoms.
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