Acute Effects of Thoracic-Spinal Elevation via a Novel Bench Press Pad on sEMG and Barbell Kinetics in Resistance-Trained Males
Joshua A. Kidwell; Trent Yamamoto; Kyle J. Hetherton; Nathan Truneh; Jacob J. Bright; August E. Blatney; Phillip Goldman; Eric Neufeld; Brett A. Dolezal
DOI: 10.70252/IJES2026103
What Was Tested—and What Was Held Constant.
Familiarize
Participants completed familiarization, practiced both conditions, and established 1-RM bench press.
Standardize
Hand width, warm-up, setup, testing time, and the 70% 1-RM external load were standardized.
Cross Over
Each participant performed five repetitions in both Standard Flat Bench and Launch Pad conditions on separate testing days.
Measure
Bilateral sEMG and a linear position transducer captured activation, velocity, power, and vertical displacement.
Raw Numbers First. Interpretation Second.
The table preserves every published outcome—including the result that did not reach statistical significance.
| Outcome | Standard Flat Bench | Launch Pad | Relative change | Adjusted p-value | Cohen’s d |
|---|---|---|---|---|---|
| Right pectoralis-major activation | 70.2 ± 24.8 %MVC | 87.3 ± 20.1 %MVC | +24.4% | < .001 | 0.76 · moderate |
| Left pectoralis-major activation | 68.3 ± 23.4 %MVC | 86.8 ± 20.0 %MVC | +27.1% | < .001 | 0.85 · large |
| Mean bar velocity | 0.40 ± 0.09 m/s | 0.47 ± 0.09 m/s | +17.5% | < .001 | 0.74 · moderate |
| Peak bar velocity | 0.57 ± 0.11 m/s | 0.66 ± 0.09 m/s | +15.8% | < .001 | 0.98 · large |
| Vertical bar displacement (reported as ROM) | 38 ± 7 cm | 44 ± 4 cm | +15.8% | = .005 | 1.02 · large |
| Concentric power | 249 ± 103 W | 271 ± 93 W | +8.8% | = .071 · not significant | 0.23 · small |
%MVC is sEMG amplitude normalized to each participant’s measured maximum voluntary contraction. ROM in this paper was defined as vertical barbell displacement—not shoulder-joint range of motion. Visual bars are normalized within each outcome and are not a shared-unit scale.
What This Means for the Athlete.
During the same five-repetition task at the same relative load, changing the athlete-to-bench interface changed several measurable features of the rep in the same trained lifters.
Same lifter. Same relative load. A measurably different rep.
With The Launch Pad®, the tested lifters showed higher recorded pectoralis-major activation, moved the bar faster, and moved it through a greater vertical distance on average than they did on the Standard Flat Bench.
That matters because it shows the surface beneath the athlete can influence how a repetition is performed—not merely how the setup feels.
Higher sEMG is not the same as more muscle growth.
sEMG reflects the electrical activity recorded from the tested surface muscle under that condition. It does not tell us that more muscle fibers grew, that hypertrophy occurred, or that every athlete will feel a stronger chest contraction.
The study was acute: it measured what happened during the test, not what accumulated over weeks of training.
Higher recorded activation amplitude on both sides.
Higher mean and peak concentric speed.
The bar traveled farther vertically on average.
Numerically higher, but not statistically significant.
What the p-Values and Cohen’s d Values Add to the Raw Results.
The raw numbers tell you what physically changed. The p-values describe statistical evidence under the model. Cohen’s d describes the size of the standardized difference relative to the variability used in the calculation.
How compatible are the data with no difference?
The four activation and velocity outcomes reported p < .001, and vertical displacement reported p = .005. Those values indicate strong incompatibility with a no-difference model under the analysis.
A p-value is not the probability that the product “works,” and it does not tell you how large the difference was.
How large was the separation relative to variability?
The paper used conventional reference points in which roughly 0.2 is small, 0.5 is moderate, and 0.8 is large. A d value is not a percentage and does not mean “times better.”
Because this was a crossover comparison, interpret these values within this design rather than ranking them against every d reported elsewhere.
What did the instruments actually record?
%MVC expresses the sEMG amplitude relative to each participant’s normalization value. m/s describes bar velocity, watts describe concentric power, and centimeters describe vertical bar displacement.
Those raw units keep the standardized statistics attached to an outcome an athlete can understand.
The moderate, large, and small descriptions above follow the conventional reference points explicitly applied by the paper. They are orientation aids, not universal biological thresholds.
An Immediate Interface Effect During the Rep.
Each participant served as his own comparison.
Every lifter completed both conditions. That reduces the influence of between-person differences such as baseline strength, anatomy, and training history when comparing the two setups.
The testing days were separated and the order was randomized, helping the study isolate the immediate condition effect.
The athlete-to-bench interface acted as an acute movement variable.
Under the tested 70% 1-RM condition, changing the interface altered pectoralis-major sEMG, mean and peak velocity, and vertical bar displacement.
The paper discusses thoracic position, scapulothoracic alignment, length–tension relationships, and neural coordination as plausible explanations. Those mechanisms were interpreted from the pattern of results rather than directly measured as separate outcomes.
Four Questions Before Programming From It.
Does my athlete resemble the sample?
Ten healthy, resistance-trained males with at least two years of consistent upper-body training were studied. Apply more cautiously outside that population.
Does my set resemble the protocol?
The experiment used one set of five explosive repetitions at 70% 1-RM with standardized hand placement and setup. Different loads, tempos, fatigue states, and repeated sets remain separate questions.
Am I using the measured outcome?
The paper measured pectoralis-major sEMG, bar velocity, concentric power, and vertical bar displacement. Do not substitute hypertrophy, pain, injury, or joint force for outcomes that were not recorded.
Am I keeping the complete result?
Activation, velocity, and displacement differed significantly. Concentric power did not reach statistical significance (p = .071). A responsible summary keeps both parts visible.
What Still Needs to Be Tested.
- Small sample of resistance-trained males only.
- One load intensity, one set, and five repetitions.
- Anthropometric differences such as limb length and thoracic curvature were not controlled.
- Surface EMG does not measure deeper stabilizers or provide a direct measure of hypertrophy.
- Separate-day testing leaves room for small differences in electrode placement, hydration, recovery, and day-to-day readiness.
- Do the acute effects persist across women, other training levels, and older athletes?
- How do different loads, tempos, and repeated sets change the response?
- What happens when scapular motion, joint kinematics, and joint forces are measured directly?
- Which acute changes predict chronic strength or hypertrophy adaptations?
- Can independent laboratories reproduce the findings under comparable conditions?
Keep the Source Attached to the Claim.
Kidwell, J. A., Yamamoto, T., Hetherton, K. J., Truneh, N., Bright, J. J., Blatney, A. E., Goldman, P., Neufeld, E., & Dolezal, B. A. (2026). Acute effects of thoracic-spinal elevation via a novel bench press pad on sEMG and barbell kinetics in resistance-trained males. International Journal of Exercise Science, 19(1), 1003. https://doi.org/10.70252/IJES2026103