The purpose of the present study was to identify the muscle and kinematic parameters associated with the emergence of a skilled organization of landing from a jump in boys 7 years to 13 years of age. Jumps were videotaped (60Hz) in the right sagittal plane. The digitized coordinates of six landmarks were used to calculate the angular position, velocity, and acceleration parameters for the hip, knee, and ankle joints. Surface EMG signals were recorded for six muscles (Tibialis Anterior, Lateral Gastrocnemius, Soleus, Vastus Lateralis, Rectus Femoris, Biceps Femoris) to obtain the pattern of muscle onsets in anticipation for landing and the modulation of the muscle activity during the impact phase. / Subjects could be classified into three distinct groups based on the pattern of muscle onsets: the Proximal-distal group (PDS), the Transitional group (TS), and the Adult group (AS). The classification reflected a progression from a proximal-distal (PDS) to a distal-proximal (AS) organization of landing. At the muscular level, the progression was associated with: (1) an increased contribution of the ankle to the anticipatory control of landing; and (2) the modulation of muscle activity to reduce the impact ground reaction forces. The strongest kinematic correlates were associated with the increased ability: (1) to manage and organize motion-dependent torques; (2) to critically modulate the joint position in anticipation of landing, and (3) to utilize anticipatory muscle activity rather than biomechanical joint limits to manage the impact ground reaction forces.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.68238 |
| Date | January 1993 |
| Creators | Pelland, Lucie |
| Contributors | McKinley, P. A. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (School of Physical and Occupational Therapy.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001397062, proquestno: AAIMM94496, Theses scanned by UMI/ProQuest. |
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