Floor plan - 2013 Annual Meeting - American Association for Hand ...

An Upper Limb Reach and Grasp Cycle for Children
Institution where the work was prepared: Stanford University, Stanford, CA, USA
Amy L. Ladd, MD; Erin Butler; Stephanie Louie; Wendy Wong; Andrew Rogers; Jessica Rose; Stanford University
Medical Center
SUMMARY:
We developed a ìReach and Graspî Cycle to evaluate upper limb motor performance in children, with consistent kinematic patterns
emerging among control subjects for seven specified joint motions. The low coefficient of variation (CV) for elbow flexion/extension in
each of the five phases of the Reach and Grasp cycle suggests a repeatable upper limb cycle for object evaluation of functional motor
performance.
INTRODUCTION:
While a normative protocol exists for evaluating lower limb gait deficits [Schutte], kinematic analysis of the upper limb is more challenging
and only recently examined [Mosqueda, Fitoussi]. We propose a ìReach and Graspî Cycle that is defined by upper limb kinematics
and is consistent among children and adolescents.
MATERIALS/METHODS:
Three-dimensional kinematic data were recorded from 17 children (9 males and 8 females, ages 5-18 years) during a single Reach and
Grasp cycle. We divided the upper limb ìReach and Graspî Cycle into five phases: 1) initial position, 2) reach and grasp an object placed
at 75% total reach, 3) retract arm, bring object toward self, 4) reach and replace object, and 5) return arm to initial position (Figure 1).
Light-reflective markers were placed on the children's torso and upper limbs, and a 3-D motion analysis system captured and processed
upper limb kinematics for seven primary joint motions of the dominant arm and trunk (Motion Analysis Corportation, Santa Rosa, CA).
We calculated the mean ± 1 standard deviation (SD) for every 2% increment of the cycle, and determined the coefficient of variation
(CV) for elbow flexion/extension. We also evaluated upper limb kinematics for one child, age 6.5 years, with mild hemiplegic cerebral
palsy (CP).
RESULTS:
Consistent normal kinematic patterns emerged for each of the seven motions: trunk flexion/ extension; shoulder elevation/ extension;
shoulder rotation; elbow flexion/ extension; Forearm pronation/ supination; wrist flexion/ extension; and ulnar/ radial deviation. The
mean ± 1 SD (CV) for peak elbow flexion/ extension in each of the five phases were: 82±13 (16%), 53±12 (22%), 127±6 (5%), 54±12 (22%),
and 82± 14 (18%). The child with mild CP demonstrated decreased shoulder elevation, increased shoulder internal rotation, and
reduced elbow extension, compared to the normative data. DISCUSSION The defined Reach and Grasp cycle has potential to provide
an effective classification system for upper limb kinematics based on 3-D motion analysis. Such a system is necessary to advance our
understanding of upper limb motor disorders and improve therapeutic modalities for the upper limb.
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