Sport-Specific ECU Injuries

ECU injuries frequently occur in Tennis and Golf however ECU injuries are also common in the rugby codes.

ECU injuries in Tennis

Tennis — Grips

The specific grip employed by the player may increase their risk of wrist injury. Before we analyse how wrist injuries occur with forehands and backhands, let’s have a refresher in what the different grips are:

In a survey of elite tennis players (13) no players utilise the continental grip for forehands. 75% use a semi or full western grip, and 23% (male)/25%(female) use an Eastern grip.

Ulnar side wrist injuries (eg: ECU tendon, TFCC etc.) occurred more often with Western grips (semi and full) whereas radial side wrist injuries occurred more often with Eastern grips (Eg: DQT, intersection syndrome etc.).

We should also try to understand why players would choose topspin (hitting up through the ball) over power (hitting through the ball). A ball with topspin may have the same velocity but it will have a slower speed from A>B. This not only gives the player a defensive advantage, creating time to return to the centre of the court, but it also will provide less room for error as it will clear the net further and drop shorter. Whereas a ball with power with the same ball velocity will have a faster speed from A>B, this will take time away from the opponent and create space. The ball will be closer to the net and will land further towards the baseline.

Tennis Strokes — Forehands

With forehand strokes a ‘semi-western’ grip increases the risk of ECU injury due to the need to ‘brush up’ through the ball in order to impart spin on the ball. At impact (see picture on right) the forearm is supinated, the wrist would also try to ‘hinge’ into radial deviation and the ECU muscle would isometrically contact to stabilise the wrist.

The higher the ball, the more supination required, the more supination, the more the wrist will require a forceful ECU isometric contraction.

The higher the ball is truck in with this grip, the more supination is required in order to flatten the racquet head to hit through the ball (see Djokovic on the left in the above picture, higher ball = increased supination). Nadal utilises a full western grip with his forehands, therefore he is at increased risk of ulnar-sided wrist injuries.

Also, repetitive supination-pronation actions can lead to stripping of the extensor retinaculum. The players do this when ‘rolling the racquet head over the ball’ which increases ball contact-time with strings increasing friction transfer and therefore topspin.

Watch Nadal in the below video at the following times:

00:29–0:33, 1:10–1:13, 2:05–2:08, 2:28–2:31.

At these times, you can see that during terminal cocking phase the forearm quickly rotates into supination, the supinated wrist is then forced into end-of-range wrist extension due to the lag of the racquet.

Tennis Strokes — Double Handed Backhand

In tennis, double-handed backhand strokes require the dominant hand to move from pronation to supination forcefully in order to impart topspin on the ball (4). However, it’s the non-dominant hand closest to the racquet head that will be supinated at impact (6). Coaches will often say that the double-handed backhand for a right hander is just a left handed forehand (and vice-versa), therefore the grip on the non-dominant hand will similar to the dominant hand in a forehand.

Biomechanical studies have shown that the non-dominant wrist is in extensive ulnar deviation during the double handed backhand (see Li Na and Maria Sharapova above) (13). Moreover, the higher the ball (see Sharapova on the left) the more supination required in order to flatten the racquet head to hit through the ball (as with a forehand).

As a side note, let us take a moment to feel sorry for tennis coaches, as they are much more prone to developing De Quervains tenosynovitis and intersection syndrome on the radial side of the wrist form high wrist flexion/extension repetition during training (13).

Coaches are susecptable to radial (thumb) side wrist injuries due to repetitive ball feeding

Tennis Strokes — Backhand Volley (low)

The ulnar side of the wrist doesn’t like low backhand volleys. I actually found this out firsthand myself (having an ECU subsheath tear). My coach finally decided to change my volley grip from semi-western (forehand) which had served me well (but could be better) to a standard Continental grip (serve grip) for better all round power. It turns out that I could have adapted to my lack of ulnar-wrist stability by utilising a semi-western grip for volleys (both forehand and backhand).

Players with ECU injuries should try a semi-western grip for backhand volleys, particularly low ones, to see if this helps with wrist stability and volley power.

Tennis — Court Surface

Of course, players at the elite level have such high training loads that it is unsustainable to continue hitting in an aggravating fashion, fortunately it is probably the seasonal court surface changes that saves them. Different court surfaces results in different ball bounce height. As discussed above, the higher the ball at contact the higher the workload for the ECU.

For example, clay Court = high ball = higher incidence of ECU tendon aggravation (eg: French Open and lead up Clay Court tournaments leading to Nadal’s injury) vs Grass Court = lower bounce.

Tennis — Racquet Strings & Weight

Interestingly, in the Tagliafico et al. (2009) survey-study, all the injured players surveyed use synthetic gut over natural gut. Synthetic strings have higher durability whereas natural gut have fantastic elasticity and maintain their pre-set tension longer. Let’s face it, if you go through as many racquets in 1min as Baghdatis does (https://www.youtube.com/watch?v=g7kS68T6ptA), who needs durability? Just get the natural gut! :)

https://www.youtube.com/watch?v=g7kS68T6ptA

Players who have increased string tension also have to impart more topspin on the ball and are therefore would also be more at risk of developing wrist injuries. Less string tension results in more contact time with the ball which provides more friction when generative topspin on the ball.

If a player changes too quickly to a heavier racquet this may also overload the upper limbs, it is common (especially with recreational players) to get shoulder impingement, tennis elbow and wrist stability issues with a sudden change to a heavier racquet. Wean the player onto the new racquet weight slowly over weeks, using the old racquet less and less.

Finally, the string gauge of your strings is important to consider, a lower gauge 15–16 reduces the strain on the wrist/elbow but also reduces racquet power in favour of control and durability.

Tennis — Everything else

As mentioned above, a small change in any of the following can reduce further wrist aggravation:

Reduce racquet weight

Use natural gut strings

strings Reduce string tension

If that doesn’t work, make a change to anything that gives a racquet ‘power’, as a racquet with power is only as good as the ability of the dynamic stability of the hand/wrist complex. Try the following:

Reduce racquet head size

Have a head light balance

Reduce racquet length

Reduce racquet stiffness

Reduce racquet beam width

String with 18x20 dense pattern

Tennis — The Kinetic Chain

50% of the energy needed to hit a forehand is generated from the legs and trunk. As with all sports, an issue in the kinetic chain can have effects downstream. We know that ankle injuries are likely to lead to anterior knee pain. Thoracic issues reducing thoracic mobility often overload upper limbs and lead to one pathology after the other from shoulder impingement, to tennis elbow, to wrist injuries. For example, if knee flexion whilst serving is less than 10 degrees in the cocking phase it places 23% greater load on the shoulder and 27% greater load on the elbow to maintain racquet head velocity. In order to maintain a set racquet head velocity, less power from the kinetic chain pre-shoulder requires a development of power from the upper limbs. The shoulder, elbow and wrist are in the energy-transfer business, not the energy-development business. They participate in the kinetic chain by transfering energy through isometric strength and dynamic stability with a healthy dose of timing. Once they become generators of power for prolonged periods, along come the overuse injuries.

In Nadal’s case, years of bilateral knee patella tendinopathy have probably lead him to this point. Knee flexion is vital in order to generate ground reaction force. Of course, it’s not just that, but as mentioned above, his calendar since the Australian open in January 2016 would have had him on clay courts with higher balls and increased amounts of topspin required.

For a great bedtime read on tennis technique and injury prevention, check out:

USTA’s sports science committee white paper on Tennis Technique and Injury Prevention, http://assets.usta.com/assets/1/USTA_Import/USTA/dps/doc_437_550.pdf

ECU injuries in Golf

In professional golf, wrist injury incidence has been reported to be up to 54% (4). Traumatic ECU subluxation can occur in the ‘leading’ wrist at impact with the ball (or with the ground, if you’re a rookie like me). The club momentum attempts to force the ‘leading’ wrist into ulnar deviation and in order to stabilise the ulnar wrist the ECU tendon contracts isometrically. However, as the trunk and upper limbs above the wrist continue into the follow-through the wrist and the club have a sudden ‘hinge’ into radial deviation in the ‘leading’ wrist. This forceful ‘hinge’ effect combined with the forceful ECU isometric contraction can result in ECU subsheath failure followed by ECU tendon subluxation (4).

ECU injuries in Rugby

“Two hands on the ball!!” yells the coach from the sideline. As it turns out, not only is this solid advice as it keeps your opponent guessing whether you will offload the ball, but it will protect your ECU tendon and subsheath as well. Running with the ball cradled against your chest places your wrist in the ECU danger position, and add in the forceful isometric ECU contraction at contact in a tackle and you are at high risk of ECU injury.