Nikki Fitness | Bikini Competitor on Instagram: "Triceps not lighting up? It’s probably your shoulder. Lock it in with your “sub-scap” and watch every tricep rep hit harder. 🔒💪 What “sub-scap” means: - A small muscle in your back—created by pulling your shoulder blade slightly down and back (think: into your back pocket) and lightly “holding a sponge” in your armpit. - It engages your lats/sub-scap so the shoulder stays stable while the elbow does the work. Why it matters: - Better isolation: