Muscle pain in the upper armMuscle pain in the upper arm occurs when you have done a (too) hard workout or lifted too much, for example. In this blog, we dive deeper into the causes of upper arm muscle pain, how to prevent it, and the most effective treatments to get pain-free again quickly. Read on to discover more about how to keep your upper arms healthy and strong. What causes muscle pain in the upper arm? Muscle pain in the upper arm is caused by several factors. Overuse is the most common cause. This can come from an over-intensive workout, heavy lifting or making a wrong movement. Sustained incorrect posture while working can also cause muscle pain.