Biomechanical Evaluation of Head Kinematics During Infant Shaking Versus Pediatric Activities of Daily Living

The Significance of Macrocephaly or Enlarging Head Circumference in Infants With the Triad

“…Biomechanical studies indicate that head impact, even from short falls of 2 feet, produces physical forces far greater than from shaking alone, and such an event can produce sufficient physical forces that can lead to the triad. 6 – 8 It has been suggested that the RHs in SBS are from the shaking and resultant traction on the retina. However, a more likely explanation for the RHs in the triad is the increased retinal vein pressure associated with the increased ICP, which leads to extrusion of blood in the retina and the RHs.…”

“… 15 – 19 As previously noted, biomechanical studies have clearly shown that the traumatic deceleration forces produced by a short fall are dramatically higher than those produced by manual shaking. 6 – 8 Neck injuries are conspicuously absent from alleged instances of manual shaking, whereas neck injuries would not necessarily be prevalent in short-fall injuries. 20 , 21 Furthermore, the link between RHs and SBS has been called into question.…”

Application of Hill’s criteria of causation to shaken baby syndrome: Further evidence that questions the existence of shaken baby syndrome

“…Moreover, the rotational accelerations generated on a biofidelic doll from a short fall are far greater than those generated from shaking [15][16][17][18] . Over the years SBS proponents have argued that short falls cannot cause the triad in spite of the compelling and consistent science that short falls produce far greater rotational head acceleration than vigorous shaking [19] .…”

“…Three studies of biofidelic dolls have evaluated the magnitude (dose) of rotational acceleration that results from shaking and from short falls [15][16][17] . Each study showed that the rotational acceleration generated by shaking a biofidelic doll is far below the threshold for causing brain injury as determined by Ommaya [14] .…”

“…There are medical conditions and diseases that have been described since the initial description of SBS in the early 1970s that can cause the triad and are summarized in several articles [17,32] . Barnes has summarized the differential diagnosis of SDH from a pediatric neuroradiologist perspective (often associated with RHs), and Lantz has reported on the differential diagnosis of retinal hemorrhages (often associated with SDH) [33,34] .…”