It was also visibly noticeable how the take off speed varied between the jumps with weights held high and jumps with weights held low
I have always been curious about the best way to perform weighted jumps. When I was younger, I was taught to do weighted jumps with dumbbells held at the shoulders. But as my strength increased and I began using heavier loads, I felt that switching to a barbell from a back squat position felt more athletic. For years I trained myself in this manner with good results. But when I started coaching athletes in the weight room, I felt the heavier loads on the back, and increased spinal loading was too risky for many of my younger, developing athletes.
With these athletes, most of which are soccer players, I used the dumbbells held in the low position (at sides) to reduce some of the spinal loading that would occur with the dumbbells (or barbell) held on the shoulders. This seemed to offer a more natural and athletic feel to the movement. As they got stronger, and the dumbbells got larger, we progressed to using a trap bar for weighted jumps because the increased size of of the dumbbells seemed change the jumping and landing mechanics.
In 2010, we started comparing the data of our athletes as they progressed from dumbbells held on the shoulder, to dumbbells held low to trap bar jumps. Each time they changed the loading pattern there seemed to be an increase in vertical performance as well as the confident way they attacked the exercise.
We decided to run a test looking at how the change in loading position or equipment type may have an effect on two different performance metrics:
- Body position – specifically torso position, hip flexion and knee position on take off
- Jump Performance – specifically height and take off velocity
We started the testing session with an unweighted counter movement jump on a Swift EZEJUMP contact mat.
EZEUMP allows us to store the weights used against the test. The EZEJUMP App also recognizes this extra weight and includes it in the overall athlete mass when calculating average power in a drop jump.
The athletes were allowed to use the arms to create more of a natural feel to the motion as we assessed their preferred biomechanical jump strategy for achieving maximum height.
Then we selected a heavy but confident load that could be used in all types of jumps (in the example below the weight was 30 kg) and we instructed each athlete to jump at maximal height for 3 repetitions with a pause and reset between each jump.
We looked at 4 different variations, two with the weight on the shoulders (in the high position) and two with the weight held at the side (in the low position).
- DB (held low)
- DB (held high)
- Barbell (on shoulders)
- Trap Bar (held low)
As you can visually see in the video, the weight held in the low position more accurately resembled the body position (torso, hip and knee angles) of the unrelated counter movement jump. It was also visibly noticeable how the take off speed varied between the jumps with weights held high and jumps with weights held low, although we did not have a device that measured take off velocity.
This seemed to explain the level of confidence and aggressiveness from which our athletes attacked jumps during training when the weight was held in the low position and more similarly resembled athletic movement positions and speeds of the unweighted jump.
When we compared the height of the jump, there was also a noticeable difference between the weight held high and the weight held low. Although all jumps were performed with the same load and effort, both the trap bar and dumbbell jumps with weight held in the low position were almost identical, 69% and 68% of unweighted jump height. But the barbell and dumbbell jumps with the weight held in the high position were 60% and 50% of unweighted jump height.
When we look at the images below (with horizontal white lines drawn on the screen to reference differences in jump height) you can see the visual representation of the different variations in the screen shots of peak height during the ‘best jump’ of each set. It became obvious to the observer that the weight held low position was giving us the best performant on the weight jump exercise.
In regards to the changes in body position during each weighted jump, we also noticed key biomechanical differences. The torso angle in the weight held low variations during the initial push into the ground (start of the vertical motion) was almost identical to the torso position in the unweighted counter movement jump. However, in the weight held high variations the torso was positioned 15-20 degrees towards the more vertical, upright position.
As this exercise is a complement to athletic performance, and we are not preparing our athletes for weightlifting competitions, it seems reasonable to prescribe exercises that allow them to train in more athletically confident positions. Since these positions are often safer (reduced vertical spinal loading) and feel faster (higher take off velocity), and resulted in higher jump performances we chose to use the dumbbell/trap bar held low variation for all of our weighted jumps.