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From The Ultimate Guide to Sets and Reps for Strength Training, I think these are pretty good common-sense guidelines for the powerlifts, based on your goals. For powerlifts, however, I would not ever go over 10 reps per set. Instead, up the weight or the sets. Too many muscle twinges can happen with higher rep powerlifts, I believe. Higher reps for small or isolated muscles are fine, eg tricep push-downs, calf lifts, curls.
Exercisers need to know their max, approximately, for their powerlifts. For example, if I can deadlift 300 lbs for one or two reps, my 80% intensity is 240 lbs. What I do with powerlifts (not saying it's the best thing to do) is a warm-up set of 10 at 50%, then 4 working sets which gradually work up to about 80%. Just for fun, about once a month I will see if I can increase my max for 1 or 2 reps but I don't count that as a working set.
What is a "muscle twinge"? Is that the feeling Chris Matthews got up his leg when hearing Obama speak? If you're concerned about muscle injuries, they are far more likely to occur at lower rep ranges (I am referring to higher intensity as measured by % of one's 1RM).
Strength and Hypertrophy(enlarging tissues) should go hand in hand. The graph is generally acceptable and accurate. Im not sure about "twinges"....maybe "spasms" or possible a buildup of metabolic waste products inhibiting muscular action(contraction/release) Electrolyte imbalances can also contribute. Higher repetitions for forearms(flexor/extensor) musculature as well as calf musculature is acceptable and the muscles can take it because of fiber type(think endurance tissues). Just to add, proper diaphragmatic breathing when going above 70% max is important(valsalva manuever avoidance) or pursed lips and pushing out on lift.