Hi there!
Well, without knowing the relevant clinical details or a detailed clinical evaluation it would be difficult to determine the cause of the symptoms. Possibilities that may need to be considered include postural issues, lack of exercise/ inadequate warm-up before physical activity, muscular causes such as strain, joint degeneration etc. I would suggest assuming a posture closest to the natural body posture while in training aside regular physical exercise. If the symptoms persist. I would suggest considering a detailed evaluation by a primary care physician or an orthopedician for an accurate diagnosis and appropriate management.
Hope this is helpful.
Take care!