Identifying stable components of the sporting movement is a key step in devising a strength program.
Informed coaches are aware of the importance of physically preparing athletes to withstand the chaotic and unpredictable environments players encounter during match play. An active component in the athletic development process is the development of strength and many coaches (rightly) intuitively sense that strength training will produce the best transfer to on field performance if the movements are performed in patterns similar to those in the sporting movement.
This assumption creates a close connection between strength, coordination & specificity.
Enter Frans Bosch
In his book “Strength Training and Coordination”, Frans Bosch outlines how sporting movements have to be improvised and adapted to the constantly changing demands of the external environment. To do this, some movements are adapted while others remain unchanged. This paves the way for Frans’ terminology of ‘attractors’ and ‘fluctuators’.
Firstly, “attractors”, are the key basic, essential, fixed movements, stable in the technical completion of the action. When the athletes' attractors are stable, they become more “robust” (resistant to perturbations) and more “resilient” (resistant to state change/tissue failure).
“Fluctuators” are the unstable components of movement that help the athlete adapt to the environment.
Therefore, Bosch states that a contextual movement must satisfy two criteria:
1) The whole movement must be as stable as possible.
2) The number of fluctuators must be as small as possible, yet sufficient to meet the demands of the environment.
Acknowledging co-contractions
Across a range of different high intensity movements like running, sprinting, changing direction, throwing, and kicking, the body creates stability by co-contracting muscles that surround regions that are under stress. These co-contractions provide stability to some segments or body regions so that they can be controlled, whilst allowing others to move.
In all human movement there are numerous ways to accomplish the same goal. In the motor learning literature, this is referred to as the “degrees of freedom”, (Latash & Latash, 1994).
For every degree of freedom there is an energy cost and we now know that attractors act to reduce the degrees of freedom to create more efficient movement.
Bosch states that the hip has 6 degrees of freedom, flexion, extension, adduction, abduction, internal and external rotation and through co-contractions the hip is restricted into one position. This position is called a hip lock (a key attractor site in many sporting contexts).
This makes the hip lock (Figure 2) a fundamental athletic posture that involves coordinating the hip joints and lumbopelvic complex to achieve a “lock position”; a single leg stance that enables efficient transfer of force and return of elastic energy throughout the leg in athletic movements. This posture is a key part of the movement pattern in maximal acceleration, sprinting at full speed and take-off in a single leg jump, pretty important in most field sports.
“The key is not to think of the hip lock as a position; it is a contraction that results in a position” Frans Bosch.
The Link…
If the hip lock connects many movements it would seem sensible to consider the hip lock exercise into our training methodology in Gaelic Football (GF).
As discussed, many explosive athletic actions involve the hip lock. In studies of GF match play, Malone et al., (2014) noted that players accelerate 184 ± 40 times per game, representing 2.6 ± 0.5 accelerations per minute with peak velocities reported at 30.3 ± 1.8 km ∙ h-1. Sprint distance analysis indicates that players cover 445 ± 269 m across 44 sprints during match play, (Malone et al., 2014). The hip lock is a key reference point for the self-organisation of toe off. The extension of the leg in the sagittal plane can be performed safely if it ends with a protective hip lock. Performing hip lock variations such as the step up in Figure 4 can help train this relationship. This sport specific strength training not only provides strength transfer but also focuses on the stable component of the movement in order to ensure transferability to high intensity activities.
Change of direction
In elite GF, players are expected to change direction in relation to game scenarios. This is exemplified by the GPS image in Figure 5 which illustrates the volume of change of direction activities completed by a half forward during 35 mins of GF match play.
Forced closure based on co-contractions around the hip (the hip lock) is a key mechanism for protecting the pelvic area against large unpredictable opposing forces during these sporting actions. When players have access to the hip lock it is particularly noticeable in abrupt changes of direction such as a sidestep or a stop and go (Figure 5), making it a desirable quality for any GF player.
To conclude, the body thinks in terms of movements, not muscles. Movements are thus designed by eliminating degrees of freedom, until a robust, efficient pattern develops. This type of thinking is lacking in the weight room. We need to find strength training exercises with a similar intention to the movements we are training for. In the image below some might see Usain Bolt wearing a Kerry GAA jersey catching a football, I see a hip lock. Good movement is good movement irrespective of context.
References
Bosch, F., & Cook, K. (2015). Strength training and coordination: an integrative approach. Rotterdam: 2010 Publishers.
Daly, C., McCarthy Persson, U., Twycross‐Lewis, R., Woledge, R. C., & Morrissey, D. (2016). The biomechanics of running in athletes with previous hamstring injury: A case‐control study. Scandinavian journal of medicine & science in sports, 26(4), 413-420.
Latash, L. P., & Latash, M. L. (1994). A new book by NA Bernstein: “On dexterity and its development”. Journal of motor behaviour, 26(1), 56-62.
Malone, S., Solan, B., Collins, K. D., & Doran, D. A. (2016 a). Positional match running performance in elite Gaelic football. Journal of Strength and Conditioning Research, 30(8), 2292-2298.
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