Eccentric Loading Protocols
How to use VOLTRA I's eccentric overload and concentric-only settings for tendinopathy management, deceleration training, and injury prevention programming.
When to introduce eccentric loading
The timing of eccentric loading in a rehab program matters significantly. Implementing eccentric training too early can be counterintuitive — eccentric loading causes considerably more physiological strain on soft tissue structures in the lengthening phase, especially under load. Introducing it before the tissue has sufficient integrity risks setback rather than adaptation.
The recommended progression is: isometrics first (acute and subacute phase) → concentrics once the tissue is desensitised and can tolerate loaded movement through range → eccentrics once concentric loading is well tolerated. Eccentrics should be introduced gradually, starting at low overload percentages, and progressed based on tissue response rather than fixed timelines.
Eccentric loading on VOLTRA I
Within Weight Training Mode, VOLTRA I offers two distinct eccentric overload options:
Option 1 — Percentage-based overload: Set an eccentric overload as a percentage of the concentric weight already selected. For example, a 25% eccentric overload on a 20 lb bicep curl automatically adds 5 lbs during the lowering phase, while the shortening phase remains at 20 lbs. The overload is calculated relative to the concentric load and applied during lengthening.
Option 2 — Absolute load overload: Add a specific numerical value of additional load to be applied during the eccentric phase, independent of the concentric weight. The clinician sets the exact additional load in lbs directly.
Both settings are accessed by tapping the small settings icon on the Weight Training Mode screen and toggling Eccentric. This is a significant practical advantage over traditional equipment — eccentric overload that previously required a training partner or specialized machine is now achievable by a single individual, solo.
Concentric-Only — Eliminates resistance on the return phase entirely. The cable retracts, then re-engages for the next concentric pull. Useful for concentric-only protocols, fatigue reduction, or when eccentric loading is contraindicated. This is often the appropriate starting point in early rehab before the tissue is ready for any eccentric load.
Clinical applications
Tendinopathy management
Progressive eccentrics are arguably the most effective way to create long-lasting tendinous adaptation and resilience after the tissue can tolerate isometric and concentric loading. Eccentric loading creates adaptation while the tissue is loaded under tension — this is the mechanism behind its effectiveness for tendinopathy rehabilitation.
VOLTRA I provides the clinician with a quantitative, specific dose prescription for eccentric load that would be nearly impossible to replicate through traditional weight equipment. Practical approach:
Set the concentric load at a comfortable level, then add eccentric overload incrementally (start with +10–15%, progress as tolerated).
The 1 lb increment precision allows progression in smaller steps than traditional equipment — particularly valuable in early stages when load tolerance is variable.
Use Concentric-Only as the starting point for patients not yet tolerating eccentric load; gradually introduce eccentric resistance as symptoms allow.
Applicable to Achilles tendinopathy, patellar tendinopathy, lateral epicondylalgia, and rotator cuff tendinopathy protocols.
Muscle hypertrophy
Eccentric overload is highly efficient for creating muscle hypertrophy and adaptations in muscle fibre size. This is because the muscle fibre has to adapt by laying down more sarcomeres in series in response to the tension created during the lengthening phase — a unique stimulus that concentric loading alone does not produce to the same degree.
Deceleration training and injury prevention
Creating durability of a muscle fibre under length reduces the risk of injury by building strength in lengthened positions. A track athlete performing hurdles, or a sprinter, regularly places the hamstring complex at full lengthened positions under high force. Training to be strong and durable in those positions has been shown to prevent muscle strain injuries.
Use moderate-to-high eccentric overload (+20–40%) to train the body's ability to absorb force.
Damper Mode can also be used for deceleration work — velocity-dependent resistance naturally creates higher loads during faster movements, training reactive braking capacity.
Cable-based eccentric work is generally lower-risk than plyometric or drop-based deceleration training, making it appropriate for earlier introduction in a return-to-sport program.
Post-surgical progressive loading
After procedures where early eccentric loading is beneficial but needs careful dosing (e.g., rotator cuff repair beyond the initial protection phase, ACL reconstruction):
Phase 1: Concentric-only (zero eccentric load) during initial healing.
Phase 2: Matched concentric/eccentric (standard Weight Training Mode, no overload).
Phase 3: Progressive eccentric overload (+10%, +15%, +20%) as tissue tolerance improves.
Each phase transition can be guided by clinical criteria (pain, swelling, functional milestones) with the assurance that the eccentric dose is precisely controlled.
Programming considerations
Eccentric overload increases delayed onset muscle soreness (DOMS), especially in deconditioned patients. Introduce gradually and monitor response over 24–48 hours.
The Assist Mode safety feature remains active during eccentric overload — if the patient stalls during the eccentric phase, the device will reduce load automatically.
Track eccentric loads in the session data (exported via CSV) to document dosing for clinical notes.
For tendinopathy protocols specifically, consider pairing eccentric work with isometric holds (using Isometric Mode) as a pain management strategy within the same session.
Related articles
VOLTRA I for Practitioners
Isometric Testing & Benchmarking
Lower Limb Rehabilitation
Isokinetic Protocols for Rehabilitation
Clinical example
Bicep curl for distal biceps tendinitis: Set the concentric (shortening) phase to 20 lbs. The clinician then adds 20–30 lbs of eccentric overload, so the bicep complex is pulling 20 lbs into flexion while controlling 40–50 lbs of resisted elbow extension during the lowering phase. This targeted eccentric overload would be nearly impossible to replicate with dumbbells or a traditional cable machine without a training partner — VOLTRA I makes it a single-person protocol.
Concentric-only in the rehab timeline
After the sub-acute phase of tissue healing has passed, the tissue is ideally desensitised and ready to be challenged through a larger range of motion — but it may not yet be able to tolerate the loaded lengthening that occurs during eccentric exercises. The Concentric-Only setting is the appropriate bridge here.
Research-supported guidelines for concentric loading in this phase:
3–4 sets of 10–15 reps: goal is to create baseline muscle hypertrophy and restore baseline strength.
Pain levels at 1–3/10 during the movement, with resolution of pain after stopping the exercise.
No compensatory movement: select a weight that does not cause compensatory patterns or tissue strain. Progressively overload over 2–4 weeks depending on injury severity and tissue sensitivity.
Contributor
Parts of this article were contributed by Dr Kyle Olandt, a physiotherapist and long-time VOLTRA advocate. A genuine thank you for his clinical expertise and generosity in sharing it with the community. Find him on Instagram at @dr.kylejordan.