Muscle outlines from Body Muscles by Ivan Vulović, Apache 2.0 — regrouped and recoloured for Muscle Train.
Kneel with knees hip-width apart, sitting back onto your heels. Place right hand behind your head, elbow out. Extend left arm forward for support. Exhale, rotate upper body right, bringing right elbow up. Hold, feel the stretch in your upper back. Inhale, return to start. Repeat on the opposite side (5-10 reps).
Engage your core. Rotate through the thoracic spine, not the lower back. Keep your neck neutral. Perform slowly and with control. Stop if you feel pain.
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