Tag Archives: biomchanics

Left-arm lateral movement

The secret of quick and efficient movement of the left arm is to use the shoulder muscles to move the arm and forearm. The hand is never the driving force behind the action. It is relaxed, and it is brought into place by the musculature of the shoulder. The forearm is then called upon for a more accurate adjustment, while the wrist and  fingers maintain their optimised positioning as described above.

The eyes determine the end point of the hand, allowing the brain to calculate the distance between the start and end positions easily.

© Jean-François Desrosby (D.Mus.)

Optimal hand position

The optimal positioning of the right and left hand is achieved through compliance with the ergonomic principles outlined in previous post.  The hand must be tilted on the ulnar side to an angle of 15 degrees at the wrist. A slight flexion toward the outside of 15 degrees at the wrist completes the positioning. Although it is impossible to maintain this optimum positioning at all times, the player will attempt to return to this position in which the fingers are free to move as often as possible.

© Jean-François  Desrosby 2015

Sleep less, work more?

Cutting the hours of sleep to get more time to work? Is it effective?

Everyone knows that a good night’s sleep is important. Not only, we rest, but the brain also uses this time to defragment the hard drive (our brain) by analyzing and classifying information in the right place. He also takes the time to make brand new bridges, completely new connections that will allow us to run perfectly our new learning.

We can maximize the effect of sleep by doing a nap after a period of intense work (particularly effective around noon). The brain then digests the information, which becomes available after our sleep. In addition, the nap will help us reduce our cortisol levels. We can systematically make a nap just before a stressful event to a halt the production of cortisol.

Lack of sleep affects our cognitive abilities, but how much?

Take the example of a student who always gets ” A ” and still ranks in the top 10% in everything she did. If she sleeps just less than seven hours a night during the week and about 6:20 the weekend, she will see her results fall in the back rows, as people that would normally get results in the lower 10%.

A study on soldiers responsible to operate a military complex showed that after a night’s sleep less, there was a 30% decline in their cognitive abilities coupled with a decline in their performance. After two nights of sleep deprivation, the drop was 60%.

When a person is sleeping less than six hours a night for five consecutive days, we observe the same effects as a person deprived of sleep for 48 hours.

Although sleep is important to maximize the effectiveness of your work. Sleep well and be more efficient than ever.

© Jean-François  Desrosby 2015

The basic positioning of the body

The first constraint encountered by the classical guitarist in his body positioning is that he must be seated.

Initially, the guitarist should try every means to respect the two axes, (i.e. the vertical and the horizontal axes). Let’s say the guitarist needs to sit as if a wire were passing trought the center of his head to go down to the tip of the coccyx.

It is very important that the head rest in the axis, both vertically and horizontally. It reaches a weight of around five kilos, nearly 8% of the total body’s mass, so it is important to keep in line in order to avoid unnecessary tension.

Despite maintaining the vertical axis, the lower back and neck must be held in slight lordosis. This prevents the discs and the fluid around them from pressing on the numerous nerves that surround the spine. As simply pressing on these nerves can cause a slowdown communication to the muscles, it is doubly important to keep this slight lordosis. Moreover, this position is also effective in the prevention of disc herniations.

If we begin at the floor, the feet must be well supported on the ground, because it is in this ground support that we draw strength and stability. Needless to say,  the use of ergonomic support for the guitar is essential. By using conventional support, it is impossible to have both feet firmly planted, and we must thus compensate for the misalignment caused by the elevation of one foot relative to the other. There are several types of ergonomic support for guitar. Those that are fully adjustable and ensure complete stability of the instrument are preferred.

Then the body weight should rest on the pins. Both have to absorb an equal weight. The pelvis must remain mobile and must move even during the practice of the instrument. This prevents the emergence of lower back tensions. The chair should be high enough so that the legs are higher than 90 degrees. In this way, part of the body weight rests on the legs. This position is one that promotes action. In addition, it results in a light natural curve in the lumbar spine, which ensures the desired slight lordosis. The abdominal muscles must be tonic to maintain the vertical axis. The rest of the shoulder girdle should be toned, but I’ll give more details in subsequent posts.

© Jean-François Desrosby (D.Mus.)