The single-arm rope triceps pressdown is an isolation movement that helps improve triceps size and strength. Using one arm at a time can increase the focus placed on the triceps during the movement.
Assume a staggered stance and face the pulley station, then grab the single rope attachment set to a high pulley with a thumbs-up grip. Holding the attachment and supporting the weight, bring your elbow to your side so your forearm is parallel to the floor. This is the start position and from here your elbow shouldn't move. Your free hand should remain at your side.
Extend your forearm straight down by contracting the triceps, twisting the rope so at the bottom the knuckles face the floor. Hold at lockout for one second before returning to the start position.
Do not allow your shoulders to move forward. Keep your chest up and shoulders back.
Do not use momentum. Focus on controlling the movement and contracting fully.
Do not allow your elbow to come up. Keep your elbow still throughout the movement.