Chain Reaction Biomechanics – Part 2. Tennis is a game played from the ground up.

In this second of the series on chain reaction as an undeniable principle of human movement, let’s start at the base and see how the foot and ankle react to the force from the ground as you move, and how that translates up the chain, when playing tennis.

My video analysis will contrast efficient with effective movement in more detail in the two initial moves, the split step and unit turn, looking more closely at how the foot/ ankle/ lower leg, reacts functionally with ground reaction force.

We all know the maxim that ‘’tennis is a game played from the ground up’’ and I will explain how authentic movement translates up the chain in function and conversely the damage any dysfunction can do and did do in my case.

My conclusion to this vlog includes a video of some of the 3D exercise matrices I use for mobility/stability in function, in all three planes, keeping me fit for life, and tennis.

Our starting point for video analysis in this vlog is still Tom’s forehand and whether more efficient footwork can have a positive impact on the stroke:

This video from the first article shows that Tom’s movement and strokes were highly effective, and he was very successful at the level he played, when younger, as his results indicated. But let’s have a closer look at his footwork.:

Both strokes are effective and demonstrate the arm driven technique prevalent in young talented athletic players but let’s look more closely at the movement at his feet and ankles.

There is no obvious split step to load and insufficient turn out of the right foot to indicate a unit turn, although both are slightly more evident further forward in the move.

Compare it with Justine which shows a split step combined with the right foot starting to turn out before landing. The pros favour this type of movement, see Federer’s split step/unit turn in most online clips of him.

To progress Tom’s footwork, my first objective was to calm the hitting arm to allow it to experience a more authentic role in the chain and at the same time allow the feet to function more efficiently:

By encouraging him to grip the racket at the neck he must rely less on the leverage of the combined length of the arm and racket for power. This is a teaching method only, to achieve the objective stated above, not a technique. You can now see a clear split step and unit turn and the impression is of a stroke played from the ground up, although a deeper squat would be more beneficial, it is clearly not an arm ball:

Unlike his previous effective stroke mechanics his feet are no longer just a staging post for an explosive arm driven motion, and they do seem to translate ground reaction force up through the body, at least more than they did.

The question remains that would the more efficient loading of the right foot and hip one would get from training with a squat/bilateral arms matrix, enable a more powerful and efficient load/explode of his hitting arm?

I also hear coaches use the verbal clue all the time ‘load the back foot’ and ‘move your weight forward’ without any further clues on how to, whereas a squat matrix using some of the many foot positions available, will train your body to decelerate the down motion in the split step and efficiently load to explode in any direction.

The body will do it subconsciously if trained in function.

I appreciate that most of us are not well acquainted with our feet, as they are mostly out of sight and out of mind and we don’t bother them until they start bothering us. While not vital to training functional movement, a brief description of the anatomy and function of the feet will help us to appreciate them more, especially their design.

By focussing in on the 3D motion at the subtalar/ankle complex it will become clearer how that drives the right reaction up the chain, vital for performance and lower risk of injury. The foot and ankle complex designation is more common for these joint motions, but the Gray Institute labels it collectively as the subtalar/ankle complex, to distinguish between the effects of the subtalar joint on the motion of the rear foot and the midfoot, but not to separate them.

While the mobile adapter function is vital, our focus on the subtalar joint in this vlog is on its role as a torque converter of the ground reaction force that drives up through the ankle and on up the chain. It’s helpful to know the biological and mechanical terms but you only need to know that the direction of movement is in all three planes of motion. Test your torque converters for yourself: stand with your feet shoulder width apart and drive your weight from the outside of both feet(lateral) to the inside of both feet (medial) and back again. Keep repeating this motion in both directions and see that the inversion/eversion at the feet (frontal plane) has become internal/external rotation (transverse plane) at it moves up the chain to the hips. You can see it and feel it by placing your hands on your thighs.

A dysfunctional subtalar joint is common and a logical consequence of the patterns of modern life for some and it certainly was for me.

I struggled with this condition in my right foot for most of my recreational sporting career, although not clearly evident until later on.

A GIFT osteopath who I saw diagnosed a locked subtalar joint in my right foot which caused the pain in my right knee and restricted the range of motion in my left hip and elsewhere on my left side during, but mostly after playing.

I had been an overly aggressive all court tennis player with no understanding of chain reaction biomechanics, and no exercise regime to speak of.

Later on, as a coach I knew the functional moves but was executing them with this dysfunction in my right foot, resulting in progressive damage to my right knee and left hip as they both were compensating for the lack of motion from the subtalar joint. Having worn out the medial side of the meniscus cartilage in my right knee I now wear a brace and my left hip needs constant attention to function well. AFS and particularly the 3DMAPS process have enabled me to keep playing and working till now, more than a decade later. I have no pain in my knee and occasional discomfort in my left hip and only wear the brace when playing. I have no issues with stiffness or soreness after playing as I used to, sometimes for days. Knee surgery might be an option for some but the pain waiting for it and after in rehab, or the financial pain that would have accompanied it, are not for me.

In the next article the video analysis will focus on the reactions up the chain that follow from the split step/unit turn particularly how they turn the trunk and what that means for the take back.

The take back is a minefield of contested opinion, but is it simply a chain reaction?

Vaughan Ebrahim LTA accredited Level 4 Senior Coach. Gray Institute, CAFS 2013, 3DMAPS 2017, FGS 2023