The effects of grip width on sticking region in bench press
By Olav Gomo and Roland Van Den Tillaar
A review by James Shmagranoff
One thing that I have always noticed whether it be in regards to myself or with a client is that any weight lifter will try any new technique to help them achieve a better 1-RM. For this reason, the title of this article immediately caught my attention in hopes of overcoming my weakest movement of the big three which I struggle to make the most amount of progress on.
Introduction
Bench press is not only a strength test in the sport of powerlifting and the Special Olympics, but also a common exercise seen for every day gym goers. The International Powerlifting Federation (IPF) states that for the lift to be done to completion without disqualification a lifter must lie on the bench in a supine position with head, shoulders, and buttocks touching the bench and feet flat on the ground. With arms straight and locked elbows, the barbell is brought down to the chest and paused before pushing the weight up and locking out the elbows. A sticking region is found during the movement when a deceleration occurs as the weight is pushed up, this can be due in part that the gravity of the bar is greater than the force applied by the lifter. The sticking region is of interest to lifters because it happens during maximal load effort, and thus can hinder progress in the movement.
Muscle length can be cause for this mechanically unfavorable sticking region, as it was found that taking a 1-RM at 12 different heights from the sternum caused decrease force. This led to the production of a force-length curve to hypothesize that it is the muscle lengths that cause the sticking region. The force-length curve can be put to the test by utilizing different grip widths independent from sternum distance at the same shoulder and elbow joint angle, as muscle length can be symbolized by joint angle. Past research on the bench press has shown that a person is stronger when using wide grip as opposed to narrow grip, but failed to study the differences in joint angle or moment arms at the elbow or shoulder joint. To discover if the sticking region occurs at the same joint angles, this study aims to find the sticking region by using three different grip widths tested by experienced powerlifters. The sticking region is hypothesized to occur independently of grip width at the same joint angle of the shoulder and elbow. This would mean that at these specific shoulder and elbow joints there is a moment of slow vertical force production for this region.
Methods
Twelve powerlifters age 19-41, healthy and male, with a nationally recognized 1-RM were used in this study. National level was determined by weight class and category, and there were National, European, and Nordic powerlifting champions in the participants. Ethical practices were exercised in the testing of this study.
Procedure: The three grips widths were performed by each participant at a randomly assigned order. Wide grip was preferred competition grip, narrow grip was bi-acromial distance, and medium was the middle of the two. Three grips were chosen only as a means to avoid fatigue. A warm-up was performed utilizing only the barbell for as many repetitions as the participant wanted. A percentage of their 1-RM, as estimated by the participant, was then used to conduct a standard warm-up. The warm-up went as follows: 8 reps at 40%, 6 reps at 60%, 3 reps at 70%, and 2 reps at 80%. Following warm-up, each participant was tested at 95% and 100%, if successful at 100%, the weight was raised by 2.5kg or 5kg until 100% could not be successful. After three attempts, the highest weight was chosen for the 1-RM to move forward with. Three reps were then completed at 80% for each following grip width to adapt to the new width. A rest period of 3-5 minutes was given to avoid fatigue, but each lifter could decide when they were ready to go again. IPF rules and regulations were used to avoid any outside influences, minus that the full pause on the chest was permitted to be a touch and press (no bounce).
Recordings: A three-dimensional 6 camera motion detector systems was used to mark measurements. Markers were placed on the left and right side of the body, lateral tip of the acromion, lateral and medial epicondyle of the elbow, the styloid process of the ulna and radius, and the middle of the barbell. Lift points tracked included the upward start movement, first peak velocity (start of sticking region), first local minimum velocity (start and end of post sticking region), and second peak velocity (deceleration phase). Position of barbell, time, velocity, joint angles, and shoulder and elbow moment arms were calculated at each point. The markers were used to help calculate joint angles during shoulder flexion and abduction and elbow extension.
Statistical analysis: Kinematics were assessed using two-way ANOVA and Bonferroni post hoc test by calculating grip width by the four lift points.
Results
No significant difference was discovered in 1-RM between narrow and medium grip, but there was a significant difference between wide grip and the other two. Velocity was found to be significantly higher with the narrow grip. Barbell position was found to be significantly higher with the narrow grip during the first peak velocity and first local minimum velocity than at both other grips but even more so at the second peak velocity compared to the wide grip. Elbow extension angle increased angle from narrow to medium to wide grip. Shoulder abduction angle was lower during the initial upward movement and first peak velocity during narrow grip, while shoulder flexion was higher with the narrow grip compared to both others except in second peak velocity. Two-way ANOVA testing at the four movement points showed that there was significant change in moment arm of the shoulder joint in all grips, decreasing significantly throughout the sticking region. The moment arm decreased in the narrow grip more than the medium, and the medium decreased more than the wide grip. Analysis of each grip done separately with one-way ANOVA testing showed that there was significant moment arm change in both narrow and wide grip, but not with medium. In the narrow grip, moment arm increases from upward start movement to first peak velocity, but it decreases from first local minimum velocity to second peak velocity. The wide grip only decreased from upward start to first local minimum velocity.
Discussion
This study hypothesized that independent of grip width a sticking region in the same joint angle of the shoulder and elbow would occur, thus showing there is a poor mechanical region during the pressing phase of the bench press. The study found that the hypothesis was incorrect in thinking that the sticking region would occur at the same joint angle. Narrow grip in the beginning of the sticking region had smaller shoulder abduction angle and larger flexion angle, while the end of the sticking region had greater shoulder flexion. A difference in elbow flexion was found between all three grips at the start of the sticking region. Because of the lateral elbow movement during the sticking region, the moment arm of the barbell in the shoulder joint was reduced, while the moment arm in the elbow did not reduce, only varied among grips. Because of the different moment arms on the elbow of each grip, this could be reason why the hypothesis was proven incorrect. Higher degree of lateral force is produced with a greater moment arm about the elbow, but a lower total force on the barbell. The study found that total force may be a specific joint angle, but vertical force happens at different joint angles. A reduced vertical force production in the three grips in the sticking phase endured similar degrees of shoulder abduction and flexion, as well as elbow extension. One limitation to the study included an inability to measure vertical and horizontal forces, and thus an unknowing in total force production. A closer look at how the force direction goes through the elbow joint may also be important for further research, as this could be the difference in moment arms changing from flexion to extension, and thus involving different muscles.
Application
The practicalities of studies such as this one here have a huge impact in a strength sports which revolve around performance in specific lifts. Even when the study disproves a hypothesis, it is still much needed information. While I hoped that this study would help optimize my own performance and my clients’ on the bench press, it is promising to know that with further research development, there may be an answer to help so many people cross that threshold into a new 1-RM. Highly specific information in studies such as this, when coupled with a properly periodized programing and other accessory work could yield unprecedented results for even the most advanced athletes.
References
Gomo, O. & Van Den Tillaar, R. (2016). The effects of grip width on sticking region in bench press. Journal of sports sciences, 34(3), 232-238. doi 10.1080/02640414.2015.1046395
Comments