BEGIN:VCALENDAR
VERSION:2.0
PRODID:icalendar-ruby
CALSCALE:GREGORIAN
X-WR-CALNAME:Thesis Defense: Matthew Robinett
X-WR-TIMEZONE:Mountain Time (US & Canada)
BEGIN:VEVENT
DTSTAMP:20260512T094132Z
UID:tag:localist.com\,2008:EventInstance_49393126966976
DTSTART:20250428T190000Z
DTEND:20250428T200000Z
DESCRIPTION:Title: Changes in Co-Activation and Lower Limb Stiffness during
  Prolonged Load Carriage\n\nProgram: Kinesiology MS\n\nCommittee Chair: Ty
 ler Brown\n\nCommittee: Tyler Brown\, Erin Mannen\, Shuqi Zhang\n\nAbstrac
 t: Introduction: Overuse musculoskeletal injuries are a common\, costly ch
 allenge for the armed services. A stiffer lower limb during routine prolon
 ged load carriage tasks may be necessary to attenuate elevated ground reac
 tion forces but further increases musculoskeletal overuse injury risk. Qua
 ntifying leg and joint stiffness provides comprehensive and joint level in
 sight into the attenuation of ground reaction forces\, and subsequent inju
 ry risk. But\, it is currently unknown how prolonged load carriage affects
  leg\, knee and ankle stiffness\, and knee and ankle muscular activation. 
 Purpose: This study sought to quantify leg\, knee\, and ankle stiffness\, 
 and the activation and coordination of associated joint musculature during
  prolonged load carriage. Methods: Sixteen participants had leg\, knee\, a
 nd ankle stiffness quantified while they walked (1.3 m/s) 60-minutes with 
 three body borne loads (0\, 15\, and 30 kg). Surface electromyography quan
 tified average muscle activation\, co-activation\, and coordination of the
  vastus lateralis (VL)\, lateral hamstrings (LH)\, tibialis anterior (TA)\
 , and gastrocnemius (GAS) during the overground walk. Statistical Analysis
 : Leg\, and knee\, and ankle joint stiffness\, and peak and average VL\, L
 H\, TA and GAS muscle activation as well as VL:LH and TA:GA co-activation 
 and coordination during pre-activity (100 ms prior to heel strike) and wei
 ght acceptance phases were submitted to analysis. Each dependent variable 
 was submitted to a linear mixed model to test the main effects and interac
 tions between body-borne load (0\, 15\, and 30 kg) and time (0\, 15\, 30\,
  45\, and 60\nminutes). Results: Body borne load increased leg\, knee\, an
 d ankle stiffness (all: p<0.001)\, while time did not impact any lower lim
 b stiffness measure (p>0.05). Body borne load decreased average VL and LH 
 amplitude (p<0.001\; p=0.006)\, and VL:LH co-\nactivation (p<0.001) and co
 ordination (p=0.011) during pre-activity as well as average VL amplitude (
 p=0.002)\, VL:LH co-activation (p<0.001)\, and VL-only coordination during
  weight acceptance. Time decreased average VL and LH amplitude (both: p=0.
 006) and VL:LH co-activation (p=0.002) during pre-activity\, and average G
 AS activity (p=0.021)\, VL:LH co-activation and coordination index (p=0.00
 4\; p=0.008) as well as VL-only coordination (p=0.037) during weight accep
 tance. Conclusion: Prolonged walking with a heavy body-borne load increase
 d lower limb biomechanics linked to musculoskeletal overuse injuries. Spec
 ifically\, the stiffer lower limb exhibited with the addition of body born
 e load may limit the ability of the lower limb musculature to attenuate th
 e larger\, faster vertical GRFs\, and increase injury risk. While the conc
 urrent decrease in knee and ankle muscle activation may be a neuromuscular
  strategy utilized by individuals to improve efficiency of prolonged walki
 ng with load. In particular\, the decreased in VL:LH muscle activity\, co-
 activation\, and coordination throughout the load carriage task may be a s
 hift of mechanical energy management strategies used by the participants t
 o minimize the cost of prolonged walking.
GEO:43.602342;-116.198653
LOCATION:Bronco Gymnasium (BGYM)\, 217
SUMMARY:Thesis Defense: Matthew Robinett
URL;VALUE=URI:https://events.boisestate.edu/event/thesis-defense-matthew-ro
 binett
CATEGORIES:Lectures and Presentations
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END:VCALENDAR