I have used papain with some marinades for goat meat. Personally I do not care much for marinades any more, at least not long ones. For example, I used to marinate chicken overnight with spices and yogurt when making chicken tikka or tandoori chicken.
1 Pain at the base of the spine causes the psoas muscle to shorten and weaken(1,2,3,). 2  80% of Western people will suffer from debilitating backpain some time in their lives(5).  Western style walking (comfortable shoes & flat ground) fails to trigger muscles that stabilize hip joints & lower back.
Multifidus is a deep muscle located along the back of the spine very close to the midline. The deep fibers are short and span single vertebral segments. This muscle functions together with transversus abdominis & pelvic floor muscles to stabilize the low back and pelvis BEFORE movement of the arms and/or legs occurs.