Master of Science (MS)
Kinesiology and Nutrition Sciences
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Second Committee Member
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This study intends to provide a basic biomechanical understanding of a specific movement within the sport of lacrosse, an overhand goal shot. Its purpose is to identify the different muscles of the lower extremity and the roles they perform during each phase of the lacrosse shot. Specifically, the study will compare how active muscles are between phases as well as between two different shot speeds. This research provides insight into the importance of timing muscle contractions that lead to a more accurate and faster shot.
Subjects (n=5 females, age: 21.8 ± 2 years, height: 162.56 ± 15.24cm, mass: 63.68 ± 23.6kg) were healthy and had at least one year of lacrosse experience. The lead leg was instrumented with electromyography (EMG) leads to measure muscle activity of the rectus femoris, biceps femoris, tibialis anterior, and the lateral and medial gastrocnemii. Subjects underwent testing for maximal voluntary isometric contraction (MVIC) for each muscle. The MVIC data was used to normalize all EMG activation amplitude data. Subjects were video recorded during five trials of a warm up speed shot (condition 1) and five trials of a game speed shot (condition 2).
Video analysis was used to identify the discrete events defining each phase and the times the events occurred. EMG data were processed by removing any zero offset, full-wave rectifying the data, and normalizing to MVIC. The times of each discrete event were used to extract electromyography data for analysis of each phase. Data were averaged per phase for each trial. Trial data were averaged per subject and subject data were averaged per condition per muscle.
Individual subject data was analyzed using a 4 (phase) x 2 (shot) ANOVA for each muscle. Statistical analyses were completed with SPSS software version 20.0. If an interaction was observed, paired t-tests were used to compare EMG between shots for each phase. Differences were noted using α=0.05 for all statistical tests.
The rectus femoris EMG was influenced by the interaction of phase and speed (p.05). EMG was significantly different between the phases, regardless of shot (p.05). There was no statistical difference between shots (p>.05) or phases (p>.05). The lateral gastrocnemius EMG was not influenced by the interaction of phase and speed (p>.05). There was no statistical difference between shots (p>.05) or phases (p>.05). The medial gastrocnemius EMG was not influenced by the interaction of phase and speed (p>.05). There was no statistical difference between phases (p>.05). EMG was different between shots, regardless of phases (p
Biomechanics; EMG; Females; Human mechanics; Lacrosse; Leg – Muscles; Lower extremity; Muscles; Women
Biomechanics | Kinesiology
Millard, Brianna, "Examination of Lower Extremity Muscle Activity during an Overhand Lacrosse Shot in Females" (2013). UNLV Theses, Dissertations, Professional Papers, and Capstones. 1864.