Always stretch and warm up/pump up your muscles before riding to prevent injury. Especially in cold climates its important to keep yourself warm because your muscles are not ready to do work. When your body is not warmed up the blood flow is not there, which may lead to muscles being torn easily and muscle weakness. If injured, for example a shoulder: Try to not do anything overexerting while still in pain or push it past its normal flexibility. As the days go on in the morning it will be the most stiff. Get the blood flowing by just running the shoulder through its range of motion. Always good to keep blood flowing, that is how the tissues repair themselves. When pain is resonable. Do some lifting to activate muscles around the joint. This will also increase stability around the joint. You will find that your shoulder will feel the best after doing a workout as a result of increased bloodflow, range of motion, strenth and stability. As weeks and months go on the pain should compeltely subside if healing is good. Improve on your form and try to to have the same thing reoccur.
Strengh training goes a long way with trials riding and with almost any other sport besides chess. If you are strong from lifting weights you will be strong when on the bike. Extra muscle mass protects joins and keeps them stable. The bike will feel lighter, this translates to increased strenth, stability, and endurance on the bike. THe bike will be easy to pull up on. Do exercies in medium to high rep to keep your muscles in good shape. Do low reps if your looking for noticble muscle mass and strength; you may be sore for many days though during recovery of doing low reps, this may translate to poor biking. Once recovered though after a week you should feel very strong on the bike.
dumbells and other freeweights when lifting properly have the ability to bring your muscles out. When you start playing with dumbells your muscles come out to play too. Grip srength forearm and bicep strength will be increased through the entire range of motion.
Deadlifts activates your lower back/whole body like no other. All your muscles come out to play from back, shoulders, arms, and legs. Start with low weight i find going any higher than 135lbs to 150lbs may not be benefical for trials. And try to rep the weight, keep it like 10 to 20 reps. This will result in yourself having a very stable and erect posture. You should stand taller and your body should feel very stable. Now get on a trials bike and pull up on the bars and balance on the back wheel and it is almost effortless compared to before lifting.
I can go on all day about weight lifting and bikes cause i love both. I beleive weight lifting helps speed injury recovery in some cases becuase blood flow is high and tissue are being strengthend. Too much rest is bad i think because it causes the injury to stagnate. Its better to keep it moving and it will return to its original state. Days after injury/surgery you want to start stretching the healed injured tissue to try to eventually match its uninjured counterpart. Scar tissue can be tight and painfull to strech sometimes but it will feel better in the long run and you will have the same range of motion as the uninjured side.<<this needs to be done. . Fight the pain!! Pain is weakness leaving the body!!!
now im just babalying. This was my 2 cents.
Pete