of the accident was twenty-five miles per hour. In testifying that the minimum speed of the Stein car was fifty-one miles per hour, the witness stated that his opinion "is based in part on the damage to the vehicles," and that in addition to the amount of speed necessary to have laid down thirty-nine feet of track, "the crash or impact damage to the vehicle or the vehicles in this case" enters into his opinion.
Aside from stating his general engineering background and qualifications to testify as to speed based on skidmarks alone (such as a determination of the coefficient of friction on the road in question), the following constitutes the entire specific testimony as to the qualifications of the witness to draw conclusions as to speed based onroot or branch of the brachial plexus will also determine the degree of axonal damage from an externally exerted force on the neck. Since the deltoid and infraspinatus muscles are supplied by two different branches of the upper trunk, the force (and hence the degree of axonal damage) may be different on each branch, explaining the differences in the deficits of shoulder abduction/external rotation in the same patient.

In conclusion, the Mallet score could not be applied to 20% of unoperated children with obstetric brachial plexus palsy because of the discrepancy of the grade of shoulder abduction and the grade of shoulder external rotation in the same patient. This suggests that the intrapartum forces on the posterior division of the upper trunk may vary from the forces on the