Next I thought I'd do a series of posts on arm and shoulder injury prevention and rehabilitation. I've heard a number of people complain about soreness after throwing. Almost everyone has a sore arm after the training camp where we throw for a few hours in a row three days straight. But even shorter training sessions can result in injury. Even Otsuka Sensei complains of a bit of tennis elbow. For me it's often soreness in the bicep tendon just above the inside of the elbow.
I'm not a medical professional so the normal disclaimer applies. If you have a medical issue while or after throwing, see an expert and get appropriate treatment. Stuff you read on social media is worth the nothing you pay for it. The posts will be reflections from my own experience and your experience may be different. But hopefully others relate to aspects of what I'll write about and may get something out of it.