Volunteers doing trail work may be tempted to lift heavy logs onto their shoulders. Our group gave up on this method years ago, as we found it way too likely to throw someone's back out. Also, if enough people fall, then that heavy timber is 5' up in the air right over them! The odds of this happening increase with each carry.

What we do instead is this: we have several 10' lengths of 1" flat or tubular webbing we buy from the climbers' section of an outdoor gear store like EMS. We tie them into 5' loops with an overhand knot. The volunteers stand in pairs, each on opposite sides of the log. Each pair has a loop of webbing, which they rig in a choker hitch or a wrap with two loops up, one on each side of the log.

On rough ground they stand ahead of their loop facing their partner, with their rear hand holding their loop. They keep their backs straight and bend at their knees if needed. When the leader calls the numbers they all lift and swing the log forward. Then they all shift forward and repeat.

On smooth ground the log can be carried. We use a 10-pound 4' crowbar or a 2x4x4' slid through the webbing loops as a handle for each pair of workers. They bend at the knees to lift, and they start walking on the leader's call.

I don't claim to be much of an expert, but we have had no injuries using this system. The webbing and 4' bars are used in dozens of other jobs too.