TY  - JOUR
T1  - Influence of Hammer Properties on Upper-Extremity Movement
Variance during Hammering
AU - Joseph E., Langenderfer AU - Sumaya, Ferdous AU - Nilanthy, Balendra 
JO  - Journal of Engineering and Applied Sciences
VL  - 15
IS  - 6
SP  - 1515
EP  - 1521
PY  - 2020
DA  - 2001/08/19
SN  - 1816-949x
DO  - jeasci.2020.1515.1521
UR  - https://makhillpublications.co/view-article.php?doi=jeasci.2020.1515.1521
KW  - Kinematics
KW  -motion
KW  -strategy
KW  -PCA
KW  -variance
AB  - The objective of this study was to characterize the variance of hammering movement and to
determine movement dimensionality as related to hammer properties. Positions of markers attached to
upper-extremity and hammers were recorded while 19 subjects hammered nails with four different hammers.
Principal movements were calculated with principal components analysis. The principal movements differed
between hammers and subjects used different principal movements indicating different movement strategies.
Contributions of principal movements to variance and differences in movement dimensionality were determined
between hammers and across subjects. Long handle hammers resulted in lower movement dimension as four
principal movements were required to explain 95% of variance. For short handle hammers five principal
movements were required to explain the same variance. Differences in explained variance and dimensionality
provide insight into effects of hammers with different properties on strategies for movement and demands on
motor control and musculoskeletal systems.
ER  -