Table 1. Displacement traveled, time, velocity, and acceleration for each phase throughout the bench press
The results for this 1-rep maximal bench press show 4 main phases throughout the lift. The first phase is the acceleration phase; followed by sticking region, max strength region and the deceleration of the bench press. In total, the whole exercise takes about 2.73 seconds to complete.
Throughout the lift, we were measuring velocity and acceleration of the bar through these 4 regions. What we found out seems to have a significant relationship from what we have learned in biomechanics. During the acceleration phase the bar is traveling at a positive velocity and acceleration. Once the bar reaches the sticking region the velocity becomes negative because the bar is slowing down in an effort to push past the sticking point, or otherwise known as the failure point for bench press. Once the bar passes through the sticking point it then has its highest acceleration during the max strength region and it also begins to have a positive velocity. Lastly, the deceleration phase shows a decrease in acceleration but a velocity that is still increasing slightly due to the fact that the bar is coming out of the max strength region and the person is trying to slow down to get ready to rack the bar.
Throughout the lift, we were measuring velocity and acceleration of the bar through these 4 regions. What we found out seems to have a significant relationship from what we have learned in biomechanics. During the acceleration phase the bar is traveling at a positive velocity and acceleration. Once the bar reaches the sticking region the velocity becomes negative because the bar is slowing down in an effort to push past the sticking point, or otherwise known as the failure point for bench press. Once the bar passes through the sticking point it then has its highest acceleration during the max strength region and it also begins to have a positive velocity. Lastly, the deceleration phase shows a decrease in acceleration but a velocity that is still increasing slightly due to the fact that the bar is coming out of the max strength region and the person is trying to slow down to get ready to rack the bar.
Acceleration Region: During the acceleration phase the bar is moving at a positive velocity and acceleration and travels approximately 48 cm before reaching the sticking region. This region is important due to the eccentric contraction that the muscle is producing to be able to prepare the muscles for the explosive phase on the way back up to complete the lift.
Sticking Region: The sticking region shows a negative velocity and acceleration because the lifter is in a less optimal position to produce a bigger force against the weight, which is why the velocity and acceleration slowed down from the acceleration phase. During this phase the bar travels 11.94 cm in an effort to push past the difficult part of the lift and complete the bench press. When doing a 1 RM max, it may take longer to push past this region especially if the lifter is struggling at all.
Max. Strength Region: Directly after pushing past the sticking region, we saw a greater velocity in the max strength region because the muscles were in a more optimal position to produce a force against the weight. During this region the acceleration is the highest at around 5.52 m/s2 and lasts for about 7.75 cm before the deceleration region begins.
Deceleration Region: The last region of the bench press is the deceleration of the bar after the maximum strength region. This region lasts for about 10.64 cm and goes until the forearm at the elbow joint is in full extension where the bar is grabbed by the spotter. During this region, the muscles are trying to slow the bar down in an attempt to stop the upward motion of the bar so it can be racked. This deceleration can be seen in the data because the acceleration slows down (as it should during a deceleration phase). The velocity is somewhat increasing, which was not expected, but may be because the individual is just pushing out of the maximum strength region where the bar was moving at its highest acceleration throughout the lift.
Ultimately, the bench press is composed of four regions that must be closely looked at when examining the kinematic variables. In regards to performance of a 1 RM max, the velocities and accelerations that are shown here are good due to the idea that the individual was able to push past the sticking region, gain a high acceleration through the max strength region and complete the lift.
A successful 1 RM bench press max utilizes all of these phases in an effort to complete the lift with ease. As discussed in articles, the sticking region is the point of failure for the bench press which makes sense as to why there was a negative velocity and acceleration because the individual is struggling to make it past this point but once they do the velocity and acceleration will be higher because the muscles are at a more optimal point to fire.
Essentially, during the acceleration phase the body is using an eccentric contraction to lower the bar, during the concentric phase when the muscles are shortened it is important to be able to push through the regions to lift the bar. If you want to be able to perform at a higher level, practice slow eccentric (acceleration phases) on the way down and be explosive through the concentric phase on the way up. Training like this will allow the muscles to get used to being explosive during the regions that really require it the most.
TECHNIQUE EVALUATION:
The force-time curve in figure 2 of the biomechanical analysis article (2) shows very similar results in the variables we measured for our performer. While our subject performed the bench press with a counter-movement, it is important to note that the bench press in the article was closely measuring the sticking point and therefore started the lift from the descended phase where the arms were flexed at the elbow joint, which shows differences in the times to certain phases of the lift. Judging by the peak acceleration of our subject in Figure 1 and the acceleration of the representative subject in Figure 2 of the article, both values of acceleration phase occurred in the maximum strength region of the lift, which is expected to increase after passing the sticking region (2). Both sticking points for the representative subject and our subject showed the least acceleration. One small difference can be seen where the minimum velocity occurs for both subjects. The representative subject in the article showed a minimum velocity at the end of the sticking point (2), while our subject’s minimum velocity occurred more toward the mid-region of the sticking point for our subject.
The sticking point is where the limb is at a disadvantageous position and the muscle has to produce the biggest force to overcome the force of the bar, therefore you would expect to see a smaller velocity and acceleration in this phase of the lift (1). Another difference to note is where the velocity seems to peak for our subject compared to the representative subject in the article. While our subject moved the bar with the greatest velocity around mid-region of the acceleration phase, the peak velocity seemed to show up around the beginning of the sticking region (2), which is most likely the point in time where the bar is transitioning from descending to ascending the bar. The greatest displacement of the bar occurs concurrently at the end of the lift for both our subject and the representative subject in the article, which is the point in time where the muscles are trying to slow the bar down in an attempt to stop the upward motion of the bar (3), so it can be racked.
Sticking Region: The sticking region shows a negative velocity and acceleration because the lifter is in a less optimal position to produce a bigger force against the weight, which is why the velocity and acceleration slowed down from the acceleration phase. During this phase the bar travels 11.94 cm in an effort to push past the difficult part of the lift and complete the bench press. When doing a 1 RM max, it may take longer to push past this region especially if the lifter is struggling at all.
Max. Strength Region: Directly after pushing past the sticking region, we saw a greater velocity in the max strength region because the muscles were in a more optimal position to produce a force against the weight. During this region the acceleration is the highest at around 5.52 m/s2 and lasts for about 7.75 cm before the deceleration region begins.
Deceleration Region: The last region of the bench press is the deceleration of the bar after the maximum strength region. This region lasts for about 10.64 cm and goes until the forearm at the elbow joint is in full extension where the bar is grabbed by the spotter. During this region, the muscles are trying to slow the bar down in an attempt to stop the upward motion of the bar so it can be racked. This deceleration can be seen in the data because the acceleration slows down (as it should during a deceleration phase). The velocity is somewhat increasing, which was not expected, but may be because the individual is just pushing out of the maximum strength region where the bar was moving at its highest acceleration throughout the lift.
Ultimately, the bench press is composed of four regions that must be closely looked at when examining the kinematic variables. In regards to performance of a 1 RM max, the velocities and accelerations that are shown here are good due to the idea that the individual was able to push past the sticking region, gain a high acceleration through the max strength region and complete the lift.
A successful 1 RM bench press max utilizes all of these phases in an effort to complete the lift with ease. As discussed in articles, the sticking region is the point of failure for the bench press which makes sense as to why there was a negative velocity and acceleration because the individual is struggling to make it past this point but once they do the velocity and acceleration will be higher because the muscles are at a more optimal point to fire.
Essentially, during the acceleration phase the body is using an eccentric contraction to lower the bar, during the concentric phase when the muscles are shortened it is important to be able to push through the regions to lift the bar. If you want to be able to perform at a higher level, practice slow eccentric (acceleration phases) on the way down and be explosive through the concentric phase on the way up. Training like this will allow the muscles to get used to being explosive during the regions that really require it the most.
TECHNIQUE EVALUATION:
The force-time curve in figure 2 of the biomechanical analysis article (2) shows very similar results in the variables we measured for our performer. While our subject performed the bench press with a counter-movement, it is important to note that the bench press in the article was closely measuring the sticking point and therefore started the lift from the descended phase where the arms were flexed at the elbow joint, which shows differences in the times to certain phases of the lift. Judging by the peak acceleration of our subject in Figure 1 and the acceleration of the representative subject in Figure 2 of the article, both values of acceleration phase occurred in the maximum strength region of the lift, which is expected to increase after passing the sticking region (2). Both sticking points for the representative subject and our subject showed the least acceleration. One small difference can be seen where the minimum velocity occurs for both subjects. The representative subject in the article showed a minimum velocity at the end of the sticking point (2), while our subject’s minimum velocity occurred more toward the mid-region of the sticking point for our subject.
The sticking point is where the limb is at a disadvantageous position and the muscle has to produce the biggest force to overcome the force of the bar, therefore you would expect to see a smaller velocity and acceleration in this phase of the lift (1). Another difference to note is where the velocity seems to peak for our subject compared to the representative subject in the article. While our subject moved the bar with the greatest velocity around mid-region of the acceleration phase, the peak velocity seemed to show up around the beginning of the sticking region (2), which is most likely the point in time where the bar is transitioning from descending to ascending the bar. The greatest displacement of the bar occurs concurrently at the end of the lift for both our subject and the representative subject in the article, which is the point in time where the muscles are trying to slow the bar down in an attempt to stop the upward motion of the bar (3), so it can be racked.
(1) Clark, R. A., Bryant, A. L., & Humphries, B. (2008). An Examination of Strength and Concentric Work Ratios During Variable Range of Motion Training. The Journal of Strength and Conditioning Research, 22(5).
(2) Elliot, B. C., Wilson, G. J., & Kerr, G. K. (1989). A biomechanical analysis of the sticking region in the bench press. Medicine and Science in Sports
and Exercise, 21(4).
(3) King, Deborah. “Kinematics” Hill Center 104. Ithaca NY, 09/02/12. Lecture Type
(2) Elliot, B. C., Wilson, G. J., & Kerr, G. K. (1989). A biomechanical analysis of the sticking region in the bench press. Medicine and Science in Sports
and Exercise, 21(4).
(3) King, Deborah. “Kinematics” Hill Center 104. Ithaca NY, 09/02/12. Lecture Type