Post by wayne on Jan 5, 2012 18:04:42 GMT -8
Hi John, how your very well, thought you might be interested in that I bought an EMG machine.
Very interesting.
So am I right in saying, that on the above example, if we split the whole upward motion into 10 parts, and I accelerated up for 60% that it “may” look like this if we could plot my force somehow;
110
110
110
110
110
110
90
70
50
30
Then zero for the transition from positive to negative.
Total, just for a reference number 900.
Even more interesting.
So am I right in saying again, that on the above example, if we split the whole upward motion into 10 parts again, and I accelerated up for 60% But came off the eccentric to the concentric where the peak forces are, that it “may” look like this if we could plot my force somehow;
150
125
125
125
110
110
90
70
50
30
Then zero for the transition from positive to negative.
Total, just for a reference number 985.
As you “said” those numbers are just rough numbers for talking purposes only, but would the above be a rough estimation only ??? As some people are saying that if you lift the same weight “very” slow for say 166mm to very fast for say 1000mm in the same time frame, that the same total or overall force will be used by or and on the muscles, we all know that you have to use more energy doing anything faster in the same time frame, and as you fail far far far faster when doing faster repetitions, my opinion is that’s it’s you have to use more total or overall force ??? My EMG {a machine that reads the electrical activity in the muscles, the force or strength that the muscles are using} machine also gave me a higher readout force the faster repetitions.
First is the most important, as it shows the EMG average muscle activity, or muscle force/strength used, as we know, the higher the average, the higher the total/overall force/strength used.
1, Fast 409, Slow 349,
2, Fast 437, Slow 346,
3, Fast 0.1, Slow 0.3,
4, Fast 0.6, Slow 0.7,
5, Fast 1104, Slow 1114,
6, Fast 146.0, Slow 193.4,
7, Fast 175.0, Slow 173.0,
1/ WRK This is the work average for the session measured in [µV]
AVG microvolts. The average readings will vary from one patient to
another.
2/ RST This is the rest average for the session measured in µV - Below
AVG 4 µV a muscle is beginning to rest.
3/ AVG This is the average onset of muscle contraction measured in
ONST seconds, readings below 1 second can be considered normal.
4/ AVG This is the average muscle release measured in seconds,
RLSE readings below 1 second can be considered normal.
5/ W/R This is the average peak value measured in µV - The value will
PEAK vary from one patient to another.
6/ WRK This is the average muscle deviation when contracting the
AVDV muscle. Readings of below 20% of WRKAVG can be
considered adequate, below 12% can be considered good.
7/ RST This is the average muscle deviation when the muscle is at rest.
AVDV Below 4 µV a muscle is beginning to rest.
MORE thank a big thank you for your time and help.
Wayne
=PhanthomJay;3695090]It really depends on the nature of the movement. If you were to raise the weight halfway up (1/4 m) in 1/4 second at constant acceleration, the acceleration would be 8 m/s^2, and since Fnet=ma, where a is 8 and m is about 4.5 kilos, then Fnet = 36 N up, which means that since the weight acts down at about 450 N, you got to push up at 486 N, or about 110 pounds. For the remainder of the upward thrust, you've got to decelerate to 0, and the weight helps you to decelerate, so the net force is 36 N down, which means you only need to apply a force of 414 N up, or about 90 pounds. Same on the downstroke, 90 pounds to the halfway point and 110 pounds back to the beginning.
Very interesting.
So am I right in saying, that on the above example, if we split the whole upward motion into 10 parts, and I accelerated up for 60% that it “may” look like this if we could plot my force somehow;
110
110
110
110
110
110
90
70
50
30
Then zero for the transition from positive to negative.
Total, just for a reference number 900.
=PhanthomJay;3695090]But it is more likely in weightlifting that the acceleration phase takes place in a much shorter time period and distance, say 0.1 second for a distance of say 1/8 m; then its constant controlled velocity from this point until you decelerate near the top. In which case your initial acceleration is 25 m/s^2, Fnet = 110 N, or your force is 450 + 110 = 560 N, or about 125 pounds. These are just rough numbers for talking purposes only, but the bottom line is that the initial liftoff and final dropoff requires the greatest force, and perhaps over 150 pounds if you accelerated quickly over an even shorter time.
Even more interesting.
So am I right in saying again, that on the above example, if we split the whole upward motion into 10 parts again, and I accelerated up for 60% But came off the eccentric to the concentric where the peak forces are, that it “may” look like this if we could plot my force somehow;
150
125
125
125
110
110
90
70
50
30
Then zero for the transition from positive to negative.
Total, just for a reference number 985.
As you “said” those numbers are just rough numbers for talking purposes only, but would the above be a rough estimation only ??? As some people are saying that if you lift the same weight “very” slow for say 166mm to very fast for say 1000mm in the same time frame, that the same total or overall force will be used by or and on the muscles, we all know that you have to use more energy doing anything faster in the same time frame, and as you fail far far far faster when doing faster repetitions, my opinion is that’s it’s you have to use more total or overall force ??? My EMG {a machine that reads the electrical activity in the muscles, the force or strength that the muscles are using} machine also gave me a higher readout force the faster repetitions.
First is the most important, as it shows the EMG average muscle activity, or muscle force/strength used, as we know, the higher the average, the higher the total/overall force/strength used.
1, Fast 409, Slow 349,
2, Fast 437, Slow 346,
3, Fast 0.1, Slow 0.3,
4, Fast 0.6, Slow 0.7,
5, Fast 1104, Slow 1114,
6, Fast 146.0, Slow 193.4,
7, Fast 175.0, Slow 173.0,
1/ WRK This is the work average for the session measured in [µV]
AVG microvolts. The average readings will vary from one patient to
another.
2/ RST This is the rest average for the session measured in µV - Below
AVG 4 µV a muscle is beginning to rest.
3/ AVG This is the average onset of muscle contraction measured in
ONST seconds, readings below 1 second can be considered normal.
4/ AVG This is the average muscle release measured in seconds,
RLSE readings below 1 second can be considered normal.
5/ W/R This is the average peak value measured in µV - The value will
PEAK vary from one patient to another.
6/ WRK This is the average muscle deviation when contracting the
AVDV muscle. Readings of below 20% of WRKAVG can be
considered adequate, below 12% can be considered good.
7/ RST This is the average muscle deviation when the muscle is at rest.
AVDV Below 4 µV a muscle is beginning to rest.
MORE thank a big thank you for your time and help.
Wayne