Concentration Curl (Digital Resistance)
Also called Digital Resistance Concentration Curl
How to do it
Sit facing a low digital-resistance cable and hold one handle palm-up with the working upper arm braced against the inside of the thigh. Curl toward the shoulder without moving the upper arm, squeeze the biceps, then lower slowly against the programmed resistance to full extension. Complete the set and repeat on the other side.
Setup
Set one digital-resistance cable low and sit far enough away for starting tension. Hold the handle palm-up, brace the working upper arm against the inner thigh, keep the wrist straight, shoulder down, and cable path clear.
Where you should feel it
Through the working biceps during the curl and loaded return with the forearm assisting, while the thigh fixes the upper arm and the core holds posture.
When to use it
Use for programmable strict unilateral biceps volume, eccentric control, and side-to-side comparison. Favor 10-20 reps per side.