Eccentric training and distil biceps tendon pain

[hellomycognomen]

Hello everyone, I recently changed my weightlifting program to focus on the eccentric contraction phase.

I have noticed that my left arm distil biceps tendon is hurting and Im having pain during biceps contraction and hand pronation/supination.

Tendon is still attached and i can feel it (stick my finger underneath it, etc) so I know its not torn but it does feel tender and hurts when I touch it.

I have laid off the training and pain is slowly going away but I wanted to see if anyone else has experience any similar issues.

I also wanted to see if there is any experience with increase tendon pain and injury due to the long eccentric (5 second) load.

I was not using very heavy weight (20lbs) dumb bell curls, fast 1 second concentric, slow 5 second eccentric, reps to failure (10)

But I was doing the eccentric with all workouts, chest, back, shoulders, arms.

Thanks for the input.
-Cheers

[MajorPectorial]

ive started throwing these excerises in myself in the hope of causing the muscle to swell on relaxatiin of the muscle when the blood rushes in to engorge the muscle after starving it by constant strain (layman term), i do it to try stretch the muscle facia more to give the muscle more space to grow. But i only do this in about 1in 4 workouts. The rest heavier but still full stretch.n flex. But with a max weight hit going into an overload.

Ive experienced similar pain a few times. Once in both arms severly whilst swimming.

If its a new routine give ur body time to repair then try it lower n build it higher each week instead of throwing it straight in that should give ur tendons time to adjust a bit. Id mix with ur normal routine a light warm up each week on em till theyre up to.scratch.

Hope this helps n gl