I have spent a number of days sleeping in a miata. This has led to subsequent insight in treating problems that this causes; starting from my hip and moving up my side.
Keeping these areas open was top priority for a while but I quickly realized that I was going to need to focus on strengthening as well. At this point the problem had moved up to affect my lumbar spine. During a backbend practice I held salabhasana for a long enough period of time that my left leg began to shake quite a bit. My right leg shook also but not quite as heavily. Rather than come down I held the posture and focused my mind on steadying the leg. I was mostly successful and did not hold the posture too much longer.
If you ask my teacher(Iyengar) he will tell you to hold the posture. To him when you feel fatigue that means your are starting to build strength/endurance and are progressing towards opening.
If you ask another teacher(Svaroopa) who I have heard consistently referred to as a “miracle worker,” she will tell you that as soon as you get to the point of shaking, you are creating tension and should come down.
Both of these have merit however, I prefer the former for my body.
Any thoughts?