Seat surface inclination may affect postural stability during Boccia ball throwing in children with cerebral palsy.
Tip the seat 15° forward and kids with bilateral spastic CP throw farther and steadier.
01Research in Context
What this study did
The team watched kids with bilateral spastic cerebral palsy throw Boccia balls while seated. They changed only one thing: the angle of the seat. Kids tried a flat seat, a seat tipped back, and a seat tipped 15° forward. Cameras and force plates tracked reach, elbow motion, and sway.
What they found
Forward tilt won. Kids reached farther, straightened the elbow more, and swayed less. Ground reaction force also lined up better, showing steadier posture. No extra gear or straps were needed—just the tilt.
How this fits with other research
Huang et al. (2014) saw the same kids hit the target just as accurately as peers, even though they moved differently. The tilt study shows one cheap fix can clean up that extra motion.
Cheng et al. (2013) strapped the legs while kids wrote. Straps helped head-trunk line-up but did not cut arm effort. Forward tilt gives the same alignment boost and also frees the arm to move farther—an upgrade, not a clash.
Medeiros et al. (2015) raised seat height during sit-to-stand and found less joint shift but no sway change. Tilt during throwing cuts sway and boosts reach. Same lab tools, different task, complementary answers: height for joint safety, tilt for active arm skills.
Why it matters
You can slide a simple wedge under any therapy bench today. A 15° forward tilt gives kids with bilateral spastic CP a bigger, smoother throw without extra equipment. Use it during game play or reaching tasks to build better elbow range and safer posture at the same time.
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02At a glance
03Original abstract
The aim of the study was to examine how seat surface inclination affects Boccia ball throwing movement and postural stability among children with cerebral palsy (CP). Twelve children with bilateral spastic CP (3 with gross motor function classification system Level I, 5 with Level II, and 4 with Level III) participated in this study. All participants underwent pediatric reach tests and ball throwing performance analyses while seated on 15° anterior- or posterior-inclined, and horizontal surfaces. An electromagnetic motion analysis system was synchronized with a force plate to assess throwing motion and postural stability. The results of the pediatric reach test (p = 0.026), the amplitude of elbow movement (p = 0.036), peak vertical ground reaction force (PVGRF) (p < 0.001), and movement range of the center of pressure (COP) (p < 0.020) were significantly affected by seat inclination during throwing. Post hoc comparisons showed that anterior inclination allowed greater amplitude of elbow movement and PVGRF, and less COP movement range compared with the other inclines. Posterior inclination yielded less reaching distance and PVGRF, and greater COP movement range compared with the other inclines. The anterior-inclined seat yielded superior postural stability for throwing Boccia balls among children with bilateral spastic CP, whereas the posterior-inclined seat caused difficulty.
Research in developmental disabilities, 2014 · doi:10.1016/j.ridd.2014.08.033