Physical strength is the ability of a person to exert force on physical objects using muscles. And maximum muscular strength is the greatest amount of force that muscles can produce in a single maximal effort. An individual's strength is determined by two factors, their genetic inheritance of muscle fiber types and their degree and type of strength training they may undertake. Individuals with a high percentage of type-1 slow twitch (endurance) fibers will be relatively weaker than a similar individual with a high proportion of type-2 fast twitch (strength) fibers, but would have a greater inherent capacity for physical capacity for physical endurance/stamina. Adequate levels of muscular strength is necessary to engage in daily activity such as lifting ,performing sports related activity and maintaining erect posture. Evaluation of current muscular strength is required to prescribe exercise schedule, evaluate progess, motivate and educate an exerciser.There are three types of strength
1) Isometric strength
2) Isokinetic strength
3) Isotonic muscle strength.
Isometric strength -
Isometric strength testing measures maximum resistance muscle can hold without any movement (static) for maximum duration. Isometric means without any change in muscle length.
Isokinetic strength -
Isokinetic muscle strength means exercising muscles generates maximum force, while keeping the speed of movement constant. isokinetic strength testing measures effective muscles force output at every point in the muscle movement range using a computer. Isokinetic testing equipments are manufactured by Biodex and Cybex.
Isotonic strength -
Isotonic muscle strength means muscle force will change through the entire range of motion. There are two ways to access isotonic muscular strength, firstly one repetition maximum where subject has to lift maximum weights with one repetition with right exercise posture. Secondly submaximal testing where subject performs submaximal lifts to estimate maximum strength. Submaximal tests are much more easy and safer to access muscular strength of exercise beginner. It is not advisable to test beginners with maximum (1 rep MAX.) resistance lifts.
Auxotonic / Allodynamic -
Auxotonic strength means muscle force gradually increases while the muscle length is shortening (pulling on a rubber band). (It is also advisable not to compare your strength results with tables or others. If your aim for fitness testing is exercise motivation and progress evalution,then current fitness testing results can be compared with your previous results. If you are testing for first time then you can use this results for risk(to start exercise) stratification, exercise prescription and education.)
Muscular (isotonic) strength testing
To measure maximum muscle strength of lower body muscle groups.This method of muscle testing measures isotonic muscle strength.It measures maximum weights lower body muscle groups can lift with one repetition. It is important to reach the maximum weight without prior fatiguing the muscles. Required material - plates, barbell and squat rack.
Always have qualified instructor to spot you; the successful repetition should have three seconds count; 1 second for the concentric action and 2 seconds for the eccentric action. One repetition maximum should be achieved within 4 sets after warm-up.
• 1 rep max - Warm up thoroughly, next begin testing by completing a set of an exercise with a weight of which maximum 15 repetition can be achieved ,wait for 3-5 minutes, have a sip of water, incrementally increase the load by 10-15 % and perform 8-10 repetition and rest for 3-5 minutes, have a water, again increase the load by 15-20 % and perform 2-4 repetition and then increase the load which subject thinks he can lift and attempt for 1 repetition maximum. If subject failed to attempt 1 rep MAX in strict form without any assistance, then reduce the load and try again. The last successful repetition, with no assistance from a spotter is 1 repetition maximum.
• Sub maximal test - This method is very easy to apply. Ask the heaviest weightload the subject can perform for MAXIMUM 10 good repetitions with strict form, convert the 10 Rep to a 1 rep maximum by dividing the weightload by 0.75.LIKEWISE,convert maximum 12 repetition to a 1 rep MAX by dividing the weight load by 0.70, convert maximum 8 rep. to 1 rep MAX by dividing the weight load by 0.80,convert maximum 6 rep. to 1 rep MAX by dividing the weight load by 0.85, convert maximum 4 rep. to 1 rep MAX by dividing the weight load by 0.90, convert maximum 2 rep. to 1 rep MAX by dividing the weight load by 0.95.
If your aim for fitness testing is exercise motivation and progress evalution, then current fitness testing results can be compared with your previous results. If you are testing for first time then you can use this results for risk (to start exercise) stratification, exercise prescription and education. It is expected that, with appropriate training between each test, the analysis would indicate an improvement.
Tests to assess muscular strength
• Lower body strength - squat (man) or leg press (woman)
• Deltoid strength - overhead press test
• Pectoralis strength - bench press test
• Forearm strength - handgrip strength test
• Posterior muscles strength (of upperbody) - chin-up or latpull-down test