The Sticking Point

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Here is an interesting paper which investigates that old problem of the

sticking point in the bench press. However, the same analysis is also

relevant to the sticking point in any other non-ballistic movements.

Note the conclusion that the sticking region does not appear to be caused by

worse leverage ( " an increase in the moment arm of the weight about the

shoulder or elbow joints " ) or by a significant decrease in muscle activity

during this region. The authors suggest that the problem may lie in the

possibility that the sticking region represents a force-reduced transition

zone between the earlier stretch-assisted acceleration-strength phase and the

later mechanically efficient maximum strength region. The use of limited

range elastic band and chain training (e.g. by Louie and the Westside

team) may play a useful role in attending to this specific deficit in the

transition zone referred to in this paper.

The relevance of analysing the force-time curve in terms of strength

qualities such as starting strength, acceleration-strength, maximal strength,

explosive strength then becomes more obvious, as discussed in Ch 2 of

" Supertraining " . A better understanding of these fundamental biomechanical

factors then enables one to plan one's training more effectively.

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Elliott BC, GJ, Kerr GK.

A biomechanical analysis of the sticking region in the Bench Press

Medicine & Science in Sports & Exercise. 21(4):450-62, Aug 1989.

The performance of ten elite powerlifters were analyzed in a simulated

competition environment using three-dimensional cinematography and surface

electromyography while bench pressing approximately 80% of maximum, a maximal

load, and an unsuccessful supramaximal attempt.

The resultant moment arm (from the sagittal and transverse planes) of the

weight about the shoulder axis decreased throughout the upward movement of

the bar. The resultant moment arm of the weight about the elbow axis

decreased throughout the initial portion of the ascent of the bar, recording

a minimum value during the sticking region, and subsequently increased

throughout the remainder of the ascent of the bar.

The electromyograms produced by the prime mover muscles (sternal portion of

pectoralis major, anterior deltoid, long head of triceps brachii) achieved

maximal activation at the beginning of the ascent phase of the lift and

maintained this level essentially unchanged throughout the upward movement of

the bar.

The sticking region, therefore, did not appear to be caused by an increase in

the moment arm of the weight about the shoulder or elbow joints or by a

minimization of muscular activity during this region.

A possible mechanism which envisages the sticking region as a force-reduced

transition phase between a strain energy-assisted *acceleration phase* and a

mechanically advantageous *maximum strength* region is postulated.

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Dr Mel C Siff

Denver, USA

Supertraining/