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Quantifying soft tissue motion following impact is important in human motion analysis as soft tissues attenuate potentially injurious forces resulting from activities such as running and jumping. This study determined the reliability of leg soft tissue position and velocity following heel impacts. A grid of black dots was applied to the skin of the right leg and foot (n = 20). Dots were automatically detected (ProAnalyst(®)) from high-speed records of pendulum and drop impacts. Three trained measurers selected columns of dots on each participant for analysis; one measurer 6 months later. Between- and within-measurer differences in kinematic variables were all relatively small (<0.8 cm for position; <3.7 cm/s for velocity) between-measurers and (<0.5 cm for position; <2.6 cm/s for velocity) within-measurer. Good (coefficients of variation (CV) ≤ 10%) to acceptable (CV > 10% and ≤20%) reliability was shown for 95% of the position measures, with mean CVs of 10% and 11% within-measurers and between-measures, respectively. Velocity measures were less reliable; 40% of the measures showed good to marginal (CV > 20% and ≤30%) reliability. This study established that leg soft tissue position data from skin markers could be obtained with good to acceptable reliability following heel impacts. Velocity data were less reliable but still acceptable in many cases.

Background: Numbers of women attending Diabetes and Pregnancy Clinics (DPC) are increasing. Potential reasons include: obesity; fertility intervention access; diagnostic changes for gestational diabetes (GDM). The DPC in London Ontario sees all pregnant women with diabetes within the catchment area with stable clinic structure and procedures. Longitudinal characteristics of GDM women were documented for demographic insights. Methods: DPC pregnancy charts were assessed for 2000-2002, 2010-2012 and 2014-2016. Data were abstracted for: age; weight, infertility interventions; GDM diagnostic method. Continuous results were analyzed by one-way analysis of variance (ANOVA), non-parametric results by Chi-square testing; p≤ 0.05 signifying significance. Conclusions: Over the study interval, women with a GDM diagnosis increased 240%. The change may be related to obesity; changes to GDM diagnostic criteria and week of testing; but not late pregnancy weight gain or use of fertility interventions. Disclosure P. Khanna: None. K. Anukam: None. L. Chow: None. E. Brydges: None. S.L. Liu: Consultant; Self; Novo Nordisk Inc., Sanofi. Research Support; Self; Physicians' Services Inc. Foundation. J. Mahon: None. T.R. Joy: Speaker's Bureau; Self; Amgen Inc., Novo Nordisk Inc., Sanofi. Other Relationship; Self; Amgen Inc., AstraZeneca, Novo Nordisk Inc. R.M. McManus: None.

Background: Muscle activations (MA) during maximum voluntary contractions (MVC) are commonly utilized to normalize muscle contributions. Isometric MVC protocols may not activate muscles to the same extent as during dynamic activities, such as falls on outstretched hands (FOOSH), that can occur during sport or recreational activities. Objective: The purpose of this study was to compare the peak MA of upper extremity muscles during isometric and dynamic MVC protocols. Methods: Twenty-four (12 M, 12 F) university-aged participants executed wrist and elbow flexion and extension actions during five-second MVC protocols targeting six upper extremity muscles (three flexors and three extensors). Each protocol [isometric (ISO); dynamic (eccentric (ECC), concentric (CON), elastic band (ELAS), un-resisted (UNRES)] consisted of three contractions (with one-minute rest periods between) during two sessions separated by one week. Muscle activation levels were collected using standard electromyography (EMG) preparations, electrode placements and equipment reported previously. Results: Overall, the ECC and CON dynamic protocols consistently elicited higher peak muscle activation levels than the ISO protocol for both males and females during both sessions. Over 95% of the CON trials resulted in mean and peak muscle activation ratios greater than ISO, with 56.3% being significantly greater than ISO (p < 0.05). Conclusion: Higher activation levels can be elicited in upper extremity muscles when resistance is applied dynamically through a full range of motion during MVC protocols.

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