Injury caused by a blunt object does not usually cause immediate soreness or pain.
You can pop a muscle
Exercise and working out
Some people experience joint or muscle pain and some dont. It is not rare to experience knee pain because your body swells when you are menstruating and can cause soreness. ~GFiZZLE
microtrauma
Lactic acid fermentation
Yes, low potassium may cause muscle pain.
Normally the main cause of muscle pain is strain or fatigue, hope this helps you :)
Minor health complications such as the common cold, muscle soreness, and bacterial infections are the most common reasons for pain in this area. However, when armpit pain occurs with lumps and soreness in the area, it may indicate serious infections or an immune condition.
There are several substances and mechanisms that cause muscle pain. The most common are immediate onset and delayed onset pain. Immediate onset pain is caused by muscle fatigue which comes from exercise of physical activity and occurs when the muscle has rerached its conditioned fatigue point. Delayed onset pain occurs 24-48 hours after the muscles have been worked to their fatigue point and are rebuilding themselves. This is the muscle soreness that many people experience when they start a new exercise program.
Delayed onset muscle soreness, DOMS, occurs following overexertion.. Pain during muscle use can be caused by a spasm, which slows arterial blood flow to the area and is referred to as claudication.
The pain is usually localized, and there may be muscle spasms or soreness when the doctor touches the area. The patient usually feels better when resting.