Written by Dr. Tyler Standifird, UVU Professor of Bio-Mechanics
The role of non-dominant swings as a part of golf training programs has attracted much debate and argument. Golf is a highly unilateral sport, where the player is trying to achieve maximal movement power and efficiency in a single side rotation. As such, individuals argue that there is no need for opposite side golf swings (right handed golfer swinging left handed), if the sport movement is centered around single side rotation. In contrast, those who support the role of opposite side training suggest that benefits from this type of training is worth the time invested for golfers of various skill levels. This paper will review the current scientific understanding and literature on the role of opposite side training for golfers as a means to increase power and efficiency.
One of the main reasons for the debate centered around this topic comes from the lack of literature related to non-dominant swing training. One study by Suzuki et al. (2022) took a group of 30 golfers both amateurs and professionals and had them swing from both their dominant and non-dominant side. They reported that professional golfers swing faster than amateurs, from both sides, not surprising given the role of speed and distance in golf success. What was interesting was that the non-dominant speeds had a strong positive correlation to the dominant speeds (p<0.01, r=0.59) and the authors suggest that “increasing CHS on the non-dominant side may increase CHS on the dominant side and that it may improve motor dysfunction and pain”. While this study lacks a longitudinal training component, it does show potential for one side speeds influencing the others in golfers for both performance improvements and mitigation of pain.
A small study that I conducted tried to help provide insights into longitudinal training from the non dominant side. In this study a group of 10 golfers completed baseline speed and force plates testing from their dominant side (right) and 6 weeks of speed training while using swings only from the non-dominant side (left). Golfers utilized the SuperSpeed Golf Training system Level 1 training, but instead of doing 3 swings from each side, they simply completed 6 left handed swings for maximum speed with all the different weight conditions. After the 6 weeks of training the golfers were brought back in and speed and force plate testing was completed from the right side to see gains in speed and force changes. Data was collected using a PRGR Launch Monitor, which has previously been shown to be very accurate and reliable for CHS and Bertec Force Plates with Noraxon video software to detect various points in the swing. Variables of interest were CHS, but also the peak vertical, lateral, and anterior/posterior forces from the lead leg during the downswing. These forces were chosen as they have previously been shown to be highly correlated to CHS.
Results from this study first showed an increase in CHS of 6.4 mph (p<0.001) which was about a 6% increase in CHS. This was a fast swinging group to begin with (baseline speeds of 109), with many years of golf experience and also many had a history of physical training. The lowest speed gain was 2 mph with the highest being 9 mph from two golfers. When looking at the Ground Reaction Force changes, the lead leg vertical force increased by nearly 175 newtons (13%), the lead leg Anterior/posterior force increased by about 30 newtons (12%) and the lead leg lateral force increased by almost 60 newtons (30%). Previous research I have conducted showed similar changes in the vertical and A/P forces, but the increase in the lateral force was considerably higher.
This study shows a few key things. First, non-dominant speed training on its own did lead to improvements in CHS and force for the golfers in the study. Additionally this finding was seen in players who already generated a high level of speed. This shows that the stimulus of non-dominant speed training may provide gains, even to players who already have efficient movement patterns that create power and speed. It also showed that the lead leg lateral force was more influenced by non dominant training only than a mixture of both. The lead leg lateral force is often called the “braking” force in the golf swing. This occurs in the downswing, when the golfer pushes hard towards the target after shifting their COM forward in a means to stop that forward momentum and have a good base of support to rotate around and push up and through. The hypothesis is that as a player swaps the lead leg to the trail leg in a non-dominant swing, they learn a bit more of how to load that leg in the lateral direction. The trail leg lateral forces in the golf swing create an important piece of the backswing to help a player stop the backward motion and shift the COM forward in the golf swing.
This study is not without limitations as well. The study did not randomize golfers to either a non-dominant or dominant or mixture of speed training to begin the study. So it could be surmised that these golfers would have had all the same gains, or even more with a different stimulus. Additionally no kinematic data was collected, and so there is no understanding of how the kinematics of the golf swing were altered as a result of this training. It did present some useful data to show the efficacy of non-dominant speed training in gaining CHS for golfers of various skill levels.
These two studies, as far as this author can see, are the only ones that have looked at non-dominant training as it relates to dominant side swings. Much more research needs to be undertaken to better understand this relationship. But there are many scientific principles that could shed light and help answer the question about the efficacy of this type of training as a part of a golf fitness plan. The rest of this paper will explore those ideas and previous studies.
Muscle contractions can occur in three different ways: concentric, isometric, and eccentric. Isometric contractions are the easiest to think about. They occur when a muscle produces force but there is no movement. A good example of this might be a wall sit or a plank. Performing these types of exercises creates muscle activity, but no motion is occurring. Concentric contractions occur when a muscle shortens and while doing so creates force to cause movement. This movement will occur in the same direction of the applied force from the muscles. A simple example would be the biceps muscles contracting when you bend your elbow (curl motion). The biceps muscles will actively pull the forearm up and towards the upper arm and shorten as they create this tension. Concentric contractions move the origin of a muscle towards the insertion and create an acceleration that is in the same direction of the applied force. Again think that as biceps (flexor muscles) contract they will create a flexion acceleration and speed the joint up in that same direction. Eccentric contractions are the opposite of concentric. Muscles will lengthen instead of shorten, the origin will move away from the insertion point, the movement will be opposite the direction of the applied force, and the muscle will create an acceleration in the opposite direction (deceleration). Eccentric contractions are about muscles' ability to slow things down in movement. If we think of the bicep elbow curl example, on the way down, if the person does nothing and engages no muscles, the weight will just flop down and the elbow will straighten (extend) quickly. To prevent that from happening the individual will engage the elbow flexor muscles (bicep) to help create some tension and force to slow down that movement and create some deceleration or acceleration in the flexion direction. This is not to move the elbow in flexion, but to slow down the elbow as it straightens. In this basic example of an arm curl, you can see that both concentric and eccentric contractions are utilized to complete the entire motion. In physical training all aspects of that muscle should be trained. It would not be wise to only train a muscle isometrically, concentrically, or eccentrically as they all play a key role in how movement is achieved. Training all contraction types is a part of every good training program.
In rotational movements like a golf swing similar things occur. For this example we will use a right handed golfer who in the backswing will rotate to their right side and in the downswing will rotate to the left side. In the backswing the golfer will rotate to the right using oblique muscles from the right and left side. These muscles will shorten in a concentric contraction to create motion and rotation in that direction. In the downswing the golfer will move the opposite way, moving much more rapidly as they rotate to the left side, now using the opposite muscles to shorten and create the fast rotation to the left side in a concentric contraction. In the downswing there will also be some slowing down that will occur at various points coming from eccentric contractions. In order for a rotational athlete to train their rotators with all the different types of muscle contractions they would need to do both dominant side rotation training and non-dominant side training. The dominant side training will hit the muscles hard for concentric speeding up and the non dominant side training will come in and train the muscles eccentrically, that way they get all of the benefits of all types of muscle contractions.
There are many ways to get the benefit of concentric and eccentric rotational training. Some of the good golf training programs will include things such as med ball rotational throws or single arm ball throws etc as well as cable rotational movements. These will always be done from both sides. Also core stabilizing exercises are often prescribed in a standing position to help the trunk muscles train in isometric fashions. Rotational med ball throws have been shown to be highly correlated to CHS. In a study by Ehlert 2023, he reported a pooled correlation value of 0.6 for med ball rotational throw power and CHS in the studies he analyzed as part of his meta analysis and review. This high correlation shows how important it is to be able to rotate powerfully, similarly to a golf swing. It is interesting to note that in this review article by Ehlert, the correlation of med ball throws for CHS was nearly identical to that reported by Suzuki when he found that non dominant golf swings had a correlation of 0.59. This suggests that non dominant swings can be equally important as dominant side rotational med ball throws.
The golf swing is a series of rotations to different directions (backswing vs downswing) that contain both accelerations and decelerations during these time periods. As such golfers are utilizing muscles of the trunk, pelvis, and arms in various ways and contraction types constantly. Some will argue that the deceleration capabilities of the body are not important, as the ball impact will slow down the golf club. While impact of the ball does slow down the golf club, a proper kinematic sequence will result in the coordinated effort of the pelvis, trunk, and arm going through a series of accelerations and decelerations all prior to impact with the ball. For example a right-handed golfer must rotate to the right side in the backswing, stop that motion, and then initiate rotation to the left side. In that downswing rotation to the left side there is a series of accelerations and decelerations that start with the pelvis, go to the trunk, and end at the arms, all prior to impact with the golf ball. As such training these muscles to contract and produce tension and forces in all contraction types is essential.
While high quality golf training programs do include rotational training from both sides, many golfers do not engage in such programs. Like most adults, golfers tend to be relatively inactive or with basic physical activity programming that would not include rotational training from either side. Thus they are missing out on training the core effectively in isometric, concentric, and eccentric contractions. This may put their body at risk for developing injuries and movement inefficiencies. Speed training programs that incorporate both side rotational training become a great way for otherwise sedentary individuals to get good rotational training of all muscles in all different types of contractions.
Learning a complex task or skill such as a golf swing can be a lifelong pursuit. Understanding ways to stimulate the brain to a greater extent, especially as time progresses can be a great way to enhance learning and skill acquisition. This theory has been greatly studied and has been described as contextual interference or in other worlds a dynamic systems theory. This theory suggests that as individuals progress in their learning of a skill, altering the demands of the practice can lead to enhancements in the response from the brain to improve learning. A study by Kirby et al. (2019) looked at how individuals who were right hand dominant responded to a training task that contained either just the dominant side or the non dominant side. The non-dominant group had elevated levels of visual and motor regions of the brain. Senff and Weigelt (2011), looked to understand how order of practice (non dominant and then dominant, or dominant and then non dominant) would compare for performance of a task compared to control groups who practiced with just one side. They found that the greatest benefits for skill acquisition performance and retention was found in the group who trained starting with the non dominant hand first compared to all other groups. These are just two examples of the many that show performance improvements in skills when training from the non dominant side.
This can be seen in a golf swing when a right hand dominant golfer is asked to make a left handed swing. You can almost see the brain working overtime to try and figure out how to make that movement from the other side. An additional study from 2021 (Gheith et al.) investigated how contralateral baseball throwing could improve throwing on the dominant side. 16 players were randomly assigned to either a control group or a group that practiced throwing with the non-dominant arm. Differences were compared for the dominant side after 4 weeks of training. The non dominant group had a 16% increase in throwing accuracy compared to the control group in addition to a significant increase in accuracy relative to velocity (more accurate at higher velocities) compared to the control group. The researchers concluded that this type of training can be an effective way to improve performance in a well-learned complex open skill like throwing. While this hasn’t been done specifically in golf, this research, and much more, suggest that non dominant golf swings can be a great avenue to improving performance.
Another common debate about non dominant side rotational training is that doing these training sessions at very high speeds is not necessary. A study by Stasinaki et al. (2019) looked at differences between fast and slow eccentric exercises. Eccentric exercises are meant to create slowing down and acceleration opposite to the motion of the body. This can be done quickly or slowly. Traditional training in the past has focused on lengthening out the time of the eccentric or down phase. This might look like a push-up moving up in 1 second (concentric) and taking 3 seconds to move down (eccentric). The researchers in this study wanted to look at differences in muscle function following 8 weeks of training either slow or fast eccentric. Both the slow and fast training groups had increases in one repetition max in a squat, with the fast group being slightly greater. Muscle thickness increased only in the slower training group. Rate of force development increased only in the fast training group by between 10% and 19%. The researchers suggested that “fast eccentric resistance training may be more appropriate for increases in rapid force production compared to slow eccentric resistance training and this may be partly due to increases in muscle fascicle length induced by fast eccentric training”. The findings from this study need to be applied to a rotational movement as this was looked at in sagittal plane motion, but it is promising to suggest that if RFD wants to be improved faster eccentric training would be more beneficial than slower. A non-dominant speed swing would be a great example of a fast eccentric training.
Asymmetry of the two sides is often debated between the groups on both sides of the dominant and non dominant training camps. There is expected to be some “functional asymmetry” that would occur because golfers are swinging much more from their dominant side. While it may not be necessarily a goal to get to even speeds on each side, having a large asymmetry may create issues with not only golf, but possibly more so activities of daily living. Being within about 10% on each side would be a good starting goal. Meaning if you can swing something from the right side 100 mph, then you should be able to swing the same thing on the left side 90 mph at minimum. This would help create a bit more balance between sides and a better coordinated muscle function not only in a golf swing but in other daily activities.
In conclusion, research is sparse when specifically considering the efficacy of non dominant speed training. One study showed correlations between non dominant and dominant side speeds in golfers of various skill levels and the other study showed that a 6-week training of non dominant only speed swings did result in speed gains and force improvements in golfers. It is important to train muscles in isometric, concentric, and eccentric muscle contractions, and all training programs recognize this importance. In rotational training, opposite side training is an effective way to accomplish this. Research has even suggested that doing faster eccentrics would lead to improvements in rate of force development not seen in slow eccentric training. While med ball throws and other rotational power training is effective (correlation to CHS of 0.6) it is similar to the correlation between non dominant side swing speeds (0.59). Many golfers will only be doing speed training as a part of rotational training and as such having them include non dominant side training would be imperative for golfers functionality and health on the golf course and in everyday life.