Part 4: Relax to react and bounce

Interestingly enough, the human foot is quite an elastic, resilient structure – the one to be responsive and reactive to mechanical forces applied, especially during locomotion. By extension, the foot can be viewed as an outer end of a bodily spring – the musculotendinous unit of the calf where the Achilles’ tendon is attached.

Tendons are elastic and passive elements that join muscles to bones – meant to be responsive to changes in their structures – stretched or shortened – mainly caused by muscle activities. So, the muscular force generated by muscle contraction is transmitted to bony structures through tendinous tissues – and that particularly occurs at articular joints – a lot in the foot and the ankle – produces joint movements necessary for bodily movements such as walking, running, lifting, to name a few. 

Given the cyclic, elastic nature of bodily movements – largely attributed to the multidimensionality of the musculotendinous system, muscle contractions – which cause joint movements – appear to be sequential, to varying extents, allowing tendinous tissues to respond to mechanical changes. In other words, muscles and tendinous tissues are constituted in ways muscle contractions and muscle relaxations can occur nearly simultaneously – complementarily – in which mechanical energy can be stored in and released by elastic responses of tendinous tissues for a subsequent movement.

And the foot – which is to correspond to the movements of the ankle and the calf – is an excellent example of all of which discussed above.

The Achilles’ tendon – which can be seen as the largest spring in the body – gets stretched and ready to shorten reflexively as the knee bends forward, pushing slightly outward in the initial phase of locomotion: the downward motion that may come with the diaphragmatic relaxation – the impetus for exhalation.

So for the best possible outcome (for the upward motion, in this context), the calf muscles in the backside need to remain relaxed to some extent until the Achilles’ tendon recoils in response to the stretch: elastic recoil, the reflexive and elastic response, mainly from connective tissues (a broad category where tendinous tissues are included) deformed by mechanical stimuli.

In other words, a sequence of muscle contractions – the drive for the upward motion – is to be stimulated by and begin with muscle relaxations that allow the Achilles’ tendon (and other connective tissues) to respond spontaneously to changes in their structures – that is, shortening when stretched, stretching when shortened, in reactive ways.

Again, the cyclic sequence of locomotion – regulated by muscle relaxations and contractions – is what needs to be understood as a whole. It, by nature, is to encompass reflexive elements – not to be controlled, say, the realm beyond conscious intervention – and thus is performed pretty autonomically – in a self-regulating manner.

Yet, most physical properties related to locomotion are trainable. But somewhat contrary to common expectation, the key to progressive improvement may lie in a very basic aspect of bodily movements: coordination abilities for subtle adjustment of posture in ways that promote cyclic mechanisms and responsiveness – fine motor control, which can be done by individuals who can breathe and walk.

Particularly, a forward-leaning posture – characterized by the neck, the shoulders, the trunk, the knees, and the ankles – all slightly relaxed and inclined forward, poised for a sequence of muscle contractions to come – is the one most likely relevant to performance efficiency. Again, a simple yet essential mechanics many of us tend to forget – or underestimate.

By extension, the levels of coordination abilities – which may be closely associated with postural tendencies individuals have but are not always conscious about – can be examined – pretty clearly – by a simple, repetitive movement: the bouncing motion.

The bouncing motion – a rapid vertical oscillation – is a sequence of reactive and cyclic movements, tightly bound up with a forward-leaning position that can be taken on various stances yet within the functional limits of the individual person. As described above, it is simple and repetitive – one to be driven by reflexive, spontaneous responses, largely attributed to the elastic, cyclic nature of tendinous tissues.

To be continued…

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