Handgrip, Pinch Grip, and Reaction Time of Firefighters and Police Officers

Handgrip strength (HGS) and pinch grip strength are related to proper hand function. Quick and accurate reaction to stimuli is critical to perceptual-motor abilities. Firefighters (FF) and police officers (PO) are routinely involved in high-intensity emergency tasks that require HGS, pinch grip strength, and reaction time (RT). PURPOSE: The purpose was to examine differences in bimanual HGS, bimanual pinch grip strength, and dominant hand RT between FF and PO in the Southwest. METHODS: Anthropometric measures of the hand were taken. HGS was measured using a hand dynamometer. Tip, key and palmar pinch grip strength were measured using a pinch gauge dynamometer. Participants completed three consecutive maximum effort trails of handgrip and pinches with both hands. Visual RT was assessed using Human Benchmark Software on an iPad. RESULTS: There was a statistically significant, low negative correlation between PO’s dominant HGS and RT (r= -.331), non-dominant HGS and RT (r= -.374), dominant key pinch and RT (r= - .345), non-dominant key pinch and RT (r= -.391), dominant palmar pinch and RT (r= -.374), non-dominant palmar pinch and RT (r= -.348). No such correlations for FFs were statistically significant. There were statistically significant differences in dominant HGS (p\u3c.001), non-dominant HGS (p\u3c.001), dominant palmar pinch (p\u3c.001), non-dominant palmar pinch (p\u3c .001), dominant tip pinch grip (p\u3c.001), non-dominant tip pinch grip (p\u3c.001), and RT (p\u3c.001) between FF and PO, with results indicating FF were stronger and had faster RT than PO. CONCLUSION: PO bimanual HGS, dominant and non-dominant key pinch, and dominant and non-dominant palmar pinch strength are related to RT. PO may practice shooting firearms more than FF, contributing to these results. FF had stronger pinch, HGS, and RT than PO, which is likely attributed to occupational differences. For example, FF have access to exercise facilities at their workplace, which may aid in increased physical fitness among FF. FF assess and process significant sensory stimuli (fire conditions, environmental events) and must quickly react to dynamic working environments. In general, PO have a more sedentary job than FF; thus, FF are more fit, stronger, and have better RT than PO

Higher Alpha/Theta Ratio May Indicate Decreased Brain Function in Older Adults during CSPFP10 Compared to Young Adults

Declined physical ability and brain function observed in elder can affect daily living activities and negatively influence the quality of life (QOL). While the extensive research has explored the changes in cortical activity related to motor control in elder, less is known about how the brain functions during a physical function test. PURPOSE: To examine the electrocortical activation in the older adults’ brain during the Continuous Scale Physical Function Performance-10 (CSPFP-10) compared to young adults. METHODS: Twenty five older adults (OLD; 75.40±7.32 yrs, 70.33±18.23 kg, 162.87±7.55 cm) and twenty five young (YOUNG; 19.88±1.72 yrs, 66.52±14.22 kg, 167.50±10.22 cm) completed CSPFP10 while frontal (F3, Fz, F4), central (C3, Cz, C4), temporal (T7, T8, P7, P8), parietal (P3, Pz P4), and occipital (O1, Oz, O2) regions’ electrocortical activation was measured using a mobile electroencephalograph (EEG). Spectral power values (μV2/Hz) for theta (θ: 4-8 Hz) and alpha (α: 8-13 Hz) band were averaged across the target electrodes. Then α/θ ratio was calculated. Data were analyzed using independent t-test. RESULTS: OLD exhibited significantly higher α/θ ratio in frontal (M=0.98 vs.0.95, pp=.02), temporal (M=1.02 vs. 0.98, p=.006) compared to YOUNG. The separated t-test showed YOUNG had higher θ and α in frontal (θ: M= 40.93 vs. 37.56, pp=.03), central (θ: M=39.68 vs. 36.43, pp=.038), and parietal θ (M=40.55 vs. 37.98, p=.001) compared to OLD. Pearson’s correlation analysis did not find any significance between brain function and CSPFP10 scores in both groups. CONCLUSION α/θ ratio in OLD showed that their α power was relatively higher than YOUNG. Increased α power indicates suppression/selective cortical processing. It might indicate that OLD had inhibitory cortical activation process during the CSPFP10 task. Decreased frontal and parietal θ in OLD may indicate diminished decision making speed and attention with aging, while lower θ power in a central region (motor cortex) implies disrupt motor control. Overall, our result may indicate that brain activation patterns become less active during aging. It’s important to enhance both physical and brain function to improve activities of daily living and QOL in elderly population

Anterior Cruciate Ligament Reconstructed Patients Who Recovered Normal Postural Control Have Dissimilar Brain Activation Patterns Compared to Healthy Controls

Postural control, which is a fundamental functional skill, reflects integration and coordination of sensory information. Damaged anterior cruciate ligament (ACL) may alter neural activation patterns in the brain, despite patients’ surgical reconstruction (ACLR). However, it is unknown whether ACLR patients with normal postural control have persistent neural adaptation in the brain. Therefore, we explored theta (4–8 Hz) and alpha-2 (10–12 Hz) oscillation bands at the prefrontal, premotor/supplementary motor, primary motor, somatosensory, and primary visual cortices, in which electrocortical activation is highly associated with goal-directed decision-making, preparation of movement, motor output, sensory input, and visual processing, respectively, during first 3 s of a single-leg stance at two different task complexities (stable/unstable) between ACLR patients and healthy controls. We observed that ACLR patients showed similar postural control ability to healthy controls, but dissimilar neural activation patterns in the brain. To conclude, we demonstrated that ACLR patients may rely on more neural sources on movement preparation in conjunction with sensory feedback during the early single-leg stance period relative to healthy controls to maintain postural control. This may be a compensatory protective mechanism to accommodate for the altered sensory inputs from the reconstructed knee and task complexity. Our study elucidates the strategically different brain activity utilized by ACLR patients to sustain postural control

Human Apolipoprotein(a) Kringle V Inhibits Ischemia-Induced Retinal Neovascularization via Suppression of Fibronectin-Mediated Angieogenesis

Retinal neovascularization is observed in progression of diabetic retinopathy. New vessels grow into the vitreous cavity in proliferative diabetic retinopathy, resulting in traction retinal detachment and vitreous hemorrhage. To overcome the catastrophic visual loss clue to these complications, efforts have been focused on the treatment of retinal neovascularization. In this study, we demonstrated the inhibitory effect of recombinant human apolipoprotein(a) kringle V (rhLK8) in an animal model of ischemia-induced retinal neovascularization. rhLK8 induced no definite toxicity on endothelial cells and retinal tissues at the therapeutic dosage. Interestingly, rhLK8 showed antiangiogenic effect, particularly on fibronectin-mediated migration of endothelial cells. Further experiments demonstrated high binding affinity of rhLK8 to alpha 3 beta 1 integrin, and suppression of it might be the mechanism of antiangiogenic effect of rhLK8. Furthermore, rhLK8 inhibited phosphorylation of focal adhesion kinase, resulting in suppression of activation of consequent p130CAS-Jun NH2-terminal kinase. Taken together, our data suggested the possible application of rhLK8 in the treatment of retinal neovascularization by suppression of fibronectin-mediated angiogenesis.Y