( ( ( The biomechanics ) ( of ( closed ( head injury ) ) ) ) ( ( involves ( ( fluid ( dynamic ( tissue ( boundary changes ) ) ) ) ( within ( ( the brain ) ( that ( ( include ( contusions ( of ( ( ( the ( gray matter ) ) and ) ( shear ( force injuries ) ) ) ) ) ) ( to ( the ( white matter ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (NNS biomechanics)) (PP (IN of) (NP (JJ closed) (NN head) (NN injury)))) (VP (VBZ involves) (NP (NP (JJ fluid) (JJ dynamic) (NN tissue) (NN boundary) (NNS changes)) (PP (IN within) (NP (NP (DT the) (NN brain)) (SBAR (WHNP (WDT that)) (S (VP (VBP include) (NP (NP (NNS contusions)) (PP (IN of) (NP (NP (DT the) (JJ gray) (NN matter)) (CC and) (NP (NN shear) (NN force) (NNS injuries))))) (PP (TO to) (NP (DT the) (JJ white) (NN matter)))))))))) (. .)))
The biomechanics of closed head injury involves fluid dynamic tissue boundary changes within the brain that include contusions of the gray matter and shear force injuries to the white matter.
(ROOT (S (NP (NNP Fluid)) (VP (VBZ is) (NP (NP (DT the) (NN term)) (PP (IN for) (NP (NP (DT a) (NN state)) (PP (IN of) (NP (NN matter))))) (SBAR (WHNP (WDT that)) (S (VP (VBZ yields) (PP (TO to) (NP (JJ sideways) (CC or) (JJ shearing) (NNS forces)))))))) (. .)))