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The purpose of this study was to develop a springboard model that could be used to predict, in future diving simulation studies, the vertical interaction forces between a diver’s feet and the board during the time of board depression and recoil. To achieve this, the characteristic parameters (effective mass, stiffness, and damping) for a Duraflex springboard were first examined using a finite element approach. The finite element results indicated that a linear model, consisting of a lumped mass and spring, could be used to simulate the actual dynamic behavior of a springboard system. The effects of damping on the board’s motion were found to be negligible and could safely be ignored. The values for the model’s parameters (board stiffness and effective board mass) were determined empirically and are reported in this paper.

The purpose of this study was to investigate the use of the Pearson Product‐Moment correlation coefficient to quantify muscle coactivation using electromyography. The subjects were two children with spastic diplegia. Surface electrodes were used to record muscle activity from the soleus and tibialis anterior muscles during voluntary attempts at dorsiflexion and plantarflexion of the ankle against resistance. The linear envelope signals were smoothed with a Hamming filter at a cutoff frequency of 4 Hz and intervals of the resultant pairs of curves subjected to the PPM test. Both subjects demonstrated significant coactivation on their right side and independent activity on the left, indicated by high positive and negative coefficients, respectively. This method shows promise for description of side differences in diplegics and for assessing the effects of physical therapy and other interventions. Clin. Anat. 11:314–319, 1998. © 1998 Wiley‐Liss, Inc.

The characteristic modeling parameters (spring stiffness and effective mass ratio) were determined experimentally for a Maxiflex “B” board. The results indicated that the Maxiflex “B” board was substantially less stiff than a Duraflex board. Most of this decrease in stiffness is a result of the added second taper in the Maxiflex “B” board. Calculations, based on theory, revealed that the perforations in the Maxiflex “B” board reduced the local stiffness over the end region of the board by an additional 10%. As a result of its greater compliancy, the Maxiflex board also had an effective mass ratio that was greater than that of the Duraflex. It was clear from these experiments that the acknowledged superiority of the Maxiflex “B” board over the Duraflex could be attributed directly to the increased compliancy found in the Maxiflex “B” board.