External exercise cues and dual task ability during gait in people with PD

Beck, Intzandt & Almeida (2018)

Gait, or walking, is a well-learned series of movements, achieved with little attention (so mostly subconscious), and facilitated by the basal ganglia. In particular, the dorsal striatum is implicated in the process, with loops to and from the sensorimotor cortex. The dorsal striatum is also the initial area of degeneration in Parkinson’s Disease, and so it makes sense that people with PD shift to a more conscious control of walking.

However, controlling gait more consciously increases the demand on attentional resources. As a result, when walking while completing a secondary task, people with PD display worsened gait – increased step time, percentage of time spent in double support, step-to-step variability, and decreased step length.

Cues can influence how movements are controlled. External cues, those that direct attention externally to the effect of an action on the environment, utilise automatic process, and sensorimotor cortical areas. Conversely, internal cues direct attention to one’s own limb movement, relying on conscious processes that linked to the frontal cortex. Continue reading “External exercise cues and dual task ability during gait in people with PD”

Frans Bosch: Fine-Tuning Motor Control

In the book, “High Performance Training for Sports”, renowned strength coach Frans Bosch outlines his methodology and philosophy, specifically for optimising running performance.

Bosch considers – though not in great depth – the motor control theory behind his coaching practices, to provide insight into why some exercises are effective at improving performance and others are not. Two control systems exist: one fast and unconsciously controlled, and one slow and consciously controlled. Many movements in sport are required to be performed so quickly and with little warning or notice that they can only be executed automatically, and without input from the working memory or executive parts of the brain. This is important when attempting to maximise transfer of training to an athlete’s sport.

 

Specificity and Transfer

Bosch outlines 5 criteria for specific transfer, whereby to enhance transfer and thus sports performance, there must be similarity in the following areas:

  1. Muscle action
  2. Limb motion
  3. Sensory information available
  4. Dominant energy system
  5. Movement result (there is better transfer when there is a clear difference between a successful and unsuccessful movement, e.g. clean > high pull in terms of transfer)

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Nick Cooper: Programming for Speed

Strength and conditioning coach for the English Institute of Sport and head of S&C for TASS Nick Cooper provides a succinct overview of the components needed to enhance an athlete’s speed. He covers general and specific preparatory exercises, the components of actual running training, a brief discussion of why weightlifting and plyometrics transfer to running speed, as well as a few extra tips such as markers to progress to running drills.

General and specific preparatory exercises are the two distinct categories of strength training for speed. General preparatory exercises are those that build an ability to tolerate the forces of running, but can also utilise movement patterns similar to running to benefit speed. They include olympic lifts and their variations, as well as dynamic lower body exercises such as jump squats and loaded single leg landings.

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Kjær et al. (2009): structural changes and function in human tendon

Tendons are pretty important. They are the connective tissue that help transfer force from the muscle to create movement of the skeleton, or in fact prevent excess movement if the body is subject to external forces that need to be resisted. Tendons withstand huge mechanical loads, and there tends (haha) to be higher tendon injuries in athletes who do a lot of jumping (example used in the article is elite volley-ball players).

The authors (of which there are many) discuss how tendons respond to loading, with a particular focus on collagen. Collagen is the predominant matrix protein found in tendon tissue. Quite simply, acute exercise increases the rate of collagen synthesis. The more collagen, the stronger the tendon right?

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