Something to chew on…
Strength Endurance – The ability to maintain muscular force over a period of time (which can be developed with movements like Lunge Hold performed for 3-5 minutes, 300 repetitions of a Cross-Crawl Supermans, etc.)
Maximal Strength – Actual strength output (such as a 1-rep-max/1RM of a lift)
Relative Strength – Amount of force created per pound/kilogram of bodyweight (or 1RM divided by body mass)
Isometric Strength – Maximal force generated without change in muscle length/against an immovable object (like in with manual holds, such as maximally bench pressing a bar up into immovable pins)
Eccentric Strength – Yielding strength (i.e. the “negative” or “lowering” portion of a movement which causes muscle to lengthen. This can be achieved in the lowering portion of a squat or push-up, and is also the case in most Slow Iso Holds done properly as you very slowly “pull” down into the greatest range of motion/fatigue to greater joint angles)
Absolute/Potential Strength – Main factor determining the speed of a movement (i.e. reason why a dude is still really fast in one sprint despite being untrained and not sprinting in months)
Explosive Strength – Creating a high amount of force in a short time (developed primarily through plyometrics)
Starting Strength – Ability to quickly begin producing force (beginning of a concentric contraction without an eccentric contraction beforehand)
Acceleration Strength – Ability to quickly reach maximal force (which can be replicated in training through catching and repelling falling loads, a la “Rebounds”, “Altitude Drops”, and Depth Jumps)
“What type of strength do I need?”
It is my amateur opinion, through what I’ve observed and tested, strength endurance (the ability to maintain muscular force over a period of time) is the most important type of strength to have in order to perform any movement safely.
So, just from a logical standpoint, all injury is caused by the body’s inability to absorb force, and muscles act as the primary force absorber in the body. They must be able to turn on and do their job on their own (independently) and with their neighboring muscles (inter-dependently) for prolonged and sustained periods of time. Building other types of strength without other a large foundation of strength endurance is possible, and is actually what I’ve found that a lot of programs do – emphasize short-term, performance-style metrics to measure skill, but ignore the foundation. To build other “types” of strength without a huge base of strength endurance is like putting a sports car engine in a golf cart. Building the foundation, honoring the amount of time that it takes to build that foundation, and continually adding to it will allow you to do your activity, hobby, or sport of choice in a safer manner and at a higher level.