For the McKenzie stretch (https://images.squarespace-cdn.com/content/v1/5e556aadfe97d3...), instead of just holding the stretch, do reps between laying flat and then going into the stretch. At the end of your final rep (I would do 8), rotate side to side gently when arched.
Dead hangs: hang from a bar for 30 seconds, completely relaxed. Then 1 minute of rest. Repeat 3 times. This decompresses your spine.
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For hamstring stretch I find using a back extension station works well, doing one leg at a time (https://m.media-amazon.com/images/I/61TQEGNUgQL._AC_UF894,10...). Let gravity pull your torso down, which will stretch your hamstring. If that's not possible, using the corner of a wall works too (https://i.ytimg.com/vi/2U4ChnuL3JM/maxresdefault.jpg)
For the McKenzie stretch (https://images.squarespace-cdn.com/content/v1/5e556aadfe97d3...), instead of just holding the stretch, do reps between laying flat and then going into the stretch. At the end of your final rep (I would do 8), rotate side to side gently when arched.
Dead hangs: hang from a bar for 30 seconds, completely relaxed. Then 1 minute of rest. Repeat 3 times. This decompresses your spine.