The CSA was the best estimate of total EE at walking and jogging speeds, the TriTrac-R3D was the best estimate of total EE at running speeds, and the SenseWear Armband was the best estimate of total EE at most speeds.

The localized delivery of exogenous, angiogenic growth factors has become a promising alternative treatment of peripheral artery disease (PAD) and critical limb ischemia. In the present study, we describe the development of a novel controlled release vehicle to promote angiogenesis in a murine critical limb ischemic model. Ionic, gelatin-based hydrogels were prepared by the carbodiimide-mediated amidation reaction between the carboxyl groups of gelatin or poly-L-glutamic acid molecules and the amine groups of poly-L-lysine or gelatin molecules, respectively. The degree of swelling of the synthesized hydrogels was assessed as a function of EDC/NHS ratios and the pH of the equilibrating medium, while the release kinetic profile of basic fibroblast growth factor (FGF-2) was evaluated in human fibroblast cultures. The degree of swelling (DS) decreased from 26.5+/-1.7 to 18.5+/-2.4 as the EDC concentration varied from 0.75 to 2.5 mg/ml. Eighty percent of the FGF-2 was released at controlled rates from gelatin-polylysine (gelatin-PLL) and gelatin-polyglutamic acid (gelatin-PLG) hydrogel scaffolds over a period of 28 days. Cell adhesion studies revealed that the negatively charged surface of the gelatin-PLG hydrogels exhibited superior adhesion capabilities in comparison to gelatin-PLL and control gelatin surfaces. Laser Doppler perfusion imaging as well as CD31(+) capillary immunostaining demonstrated that the controlled release of FGF-2 from ionic gelatin-based hydrogels is superior in promoting angiogenesis in comparison to the bolus administration of the growth factor. Over 4 weeks, FGF-2 releasing gelatin-PLG hydrogels exhibited marked reperfusion with a Doppler ratio of 0.889 (+/-0.04) which was 69.3% higher than in the control groups.

Background Deep neck flexor (DNF) muscles stabilize the neck and contribute to head acceleration control. The function of DNF in cervical spine dynamic stabilization has not been examined in athletes of any age group, including adolescents. This investigation was necessary prior to studying the DNF muscles' role in cervical spine injury patterns. Objectives The objectives of this study were (1) to determine average Deep Neck Flexor Endurance Test (DNFET) time scores in high school−aged and university‐aged subjects (aged 14‐22 years); and (2) to establish the relationship between gender and age for adolescent DNFET time scores. Design Cross‐sectional design. Setting Public high school and private university. Participants A total of 81 (40 male, 41 female) healthy high school and collegiate athletes. Intervention DNFET time scores (in seconds) were collected and means values were calculated. Interrater reliability was established using the first 15 university‐aged subjects enrolled in the study. Main Outcomes Mean DNFET time (seconds) scores. Results The DNF muscle endurance interrater reliability coefficient of reproducibility for 4 allied health clinicians was intraclass correlation coefficient (2,4) 0.712 (confidence interval, 0.24‐0.85). The mean (± standard deviation) DNFET time score for females was 31.86 (±8.53) seconds versus 35.57 (±10.43) seconds for males. The DNFET performance demonstrated a significant but fair correlation with age (r = 0.401, P = .0001). No significant performance differences were found between male and female subjects in the 14‐ to 17‐year‐old group (U = 187.0, P = .285), the 18‐ to 22‐year‐old group (U = 145.0, P = .215), or the total male versus female subject groups (U = 653.0, P = .083). Conclusion Our study establishes a normative data set available for the DNFET in the adolescent population. The fair correlation between DNFET time scores and age is consistent with other studies. These findings serve as a basis for clinician testing, objectifying, and monitoring DNF dysfunction in an adolescent athletic population. Level of Evidence II

Volitional preemptive abdominal contraction decreases some of the detrimental effects of fatigue on landing biomechanics and thus may reduce spine injury risk in individuals with recurrent LBP.