Muscular strength refers to the amount of force produced in a muscle or group of muscles when performing a task or movement. I say “task” or movement because you can produce force while not actually moving through space. An isometric muscle contraction is a muscle acting without moving. Either it is acting upon an immovable object or it, the muscle(s), are resisting an outside force and immobile by result.
Strength is contextual. I cannot tell just by you pushing into my hand if you are strong. Strong as compared to what? Strong in comparison to perhaps the most recent person that also pressed into my hand? Sure, but comparing two individuals with no further context on why the strength matters means nothing.
How strong do you need to be? When I have this conversation with a client or a friend it usually comes down to a few things:
Strong enough to handle the basic incoming stress and force that a typical human will encounter.
That means that you need to be strong enough to get in and out of your car to drive to work without injuring yourself. You need to be strong enough to handle the ground forces going through your body while walking. You need to be strong enough to get up from the ground, etc.
You need to be strong enough to handle the stresses and forces that your personal, contextual, environment will place on you.
That means that if you play soccer. You have to be strong enough to be able to hand the force of walking (because you are still a basic human) anddddd the increased forces of sprinting, kicking, heading a ball that you will now face while playing soccer. If you play football, you have to still handle the forces of getting in and out of your car (because human…) and now be strong enough to move your 250lb+ opponent out of the way effectively, to be successful, and safely, to not get hurt and risk your playing time. If you are a mother, you must be able to walk andddd be able to lift your growing baby multiple times throughout the day, etc.
You need to be a little stronger than all the aforementioned because the aforementioned are theoretical, organized events where chaos and randomness are controlled.
In soccer, you have to be strong enough to walk to your car to drive to the game. You have to be specifically strong enough to perform highly to be effective and strong enough to mitigate injury in your game. And you also have to be a little stronger than the “predictable” parts of your life and sport because predictable is the last thing that life and sport are. Sometimes you trip walking down the street and roll an ankle instead of walking nicely on your feet. Sometimes you slip on the muddy field and land in an awkward position.
All of these situations apply to each and everyone of us when it comes to “What is strong?” and “How strong do I need to be?” Now, reflect on who who are and ask yourself those questions. Can you see how you being a human determines basic strength and your personal life determines specific strength requirements?