Horizontal force production and multi-segment foot kinematics during the acceleration phase of bend sprinting

This paper investigated horizontal force production, foot kinematics and metatarsophalangeal (MTP) joint push-off axis use during acceleration in bend (anti-clockwise) and straight-line sprinting. It was hypothesised that bend sprinting would cause the left step push-off to occur about the oblique axis, resulting in a decrease in propulsive force. Three-dimensional kinematic and ground reaction force data were collected from nine participants during sprinting on the bend (36.5 m radius) and straight. Anteroposterior force was reduced at 38-44% of stance during bend sprinting compared with the straight. This coincided with an increase in mediolateral force for the majority of the stance phase (3-96%) on the bend compared with the straight. In addition, a lower propulsive impulse was reported on the bend compared with the straight. Analysis of multi-segment foot kinematics provides insight into the possible mechanisms behind these changes in force production. Mean mediolateral centre of pressure position was more lateral in relation to the second metatarsal head in the left step on the bend compared with the straight, indicating the oblique axis was used for push-off at the MTP joint. Greater peak joint angles of the left foot were also reported, in particular, an increase in left step midfoot eversion and internal ankle rotation. It is possible these changes in joint kinematics are associated with the observed decrease in propulsive force. Therefore, practitioners should seek to strengthen muscles such as tibialis posterior in frontal and sagittal planes and ensure specificity of training which may aid in addressing these force reductions

Chenodeoxycholic acid stimulates glucagon-like peptide-1 secretion in patients after Roux-en-Y gastric bypass

Postprandial secretion of glucagon‐like peptide‐1 (GLP‐1) is enhanced after Roux‐en‐Y gastric bypass (RYGB), but the precise molecular mechanisms explaining this remain poorly understood. Plasma concentrations of bile acids (BAs) increase after RYGB, and BAs may act as molecular enhancers of GLP‐1 secretion through activation of TGR5‐receptors. We aimed to evaluate GLP‐1 secretion after oral administration of the primary bile acid chenodeoxycholic acid (CDCA) and the secondary bile acid ursodeoxycholic acid (UDCA) (which are available for oral use) in RYGB‐operated participants. Eleven participants (BMI 29.1 ± 1.2, age 37.0 ± 3.2 years, time from RYGB 32.3 ± 1.1 months, weight loss after RYGB 37.0 ± 3.1 kg) were studied in a placebo‐controlled, crossover‐study. On three different days, participants ingested (1) placebo (water), (2) UDCA 750 mg, (3) CDCA 1250 mg (highest recommended doses). Oral intake of CDCA increased plasma concentrations of GLP‐1, C‐peptide, glucagon, peptide YY, neurotensin, total bile acids, and fibroblast growth factor 19 significantly compared with placebo (all P < 0.05 for peak and positive incremental area‐under‐the‐curve (piAUC)). All plasma hormone concentrations were unaffected by UDCA. Neither UDCA nor CDCA changed glucose, cholecystokinin or glucose‐dependent insulinotropic polypeptide (GIP) concentrations. In conclusion, our findings demonstrate that the primary bile acid chenodeoxycholic acid is able to enhance secretion of gut hormones when administered orally in RYGB‐operated patients—even in the absence of nutrients

Olfaction: anatomy, physiology and behavior

The anatomy, physiology and function of the olfactory system are reviewed, as are the normal effects of olfactory stimulation. It is speculated that olfaction may have important but unobtrusive effects on human behavior

Combined rotation scarf and Akin osteotomies for hallux valgus: a patient focussed 9 year follow up of 50 patients

<p>Abstract</p> <p>Background</p> <p>The Cochrane review of hallux valgus surgery has disputed the scientific validity of hallux valgus research. Scoring systems and surrogate measures such as x-ray angles are commonly reported at just one year post operatively but these are of dubious relevance to the patient. In this study we extended the follow up to a minimum of 8 years and sought to address patient specific concerns with hallux valgus surgery. The long term follow up also allowed a comprehensive review of the complications associated with the combined rotation scarf and Akin osteotomies.</p> <p>Methods</p> <p>Between 1996 and 1999, 101 patients underwent rotation scarf and Akin osteotomies for the treatment of hallux valgus. All patients were contacted and asked to participate in this study. 50 female participants were available allowing review of 73 procedures. The average follow up was over 9 years and the average age at the time of surgery was 57. The participants were physically examined and interviewed.</p> <p>Results</p> <p>Post-operatively, in 86% of the participants there were no footwear restrictions. Stiffness of the first metatarsophalangeal joint was reported in 8% (6 feet); 10% were unhappy with the cosmetic appearance of their feet, 3 feet had hallux varus, and 2 feet had recurrent hallux valgus. There were no foot-related activity restrictions in 92% of the group. Metatarsalgia occurred in 4% (3 feet). 96% were better than before surgery and 88% were completely satisfied with their post-operative result. Hallux varus was the greatest single cause of dissatisfaction. The most common adverse event in the study was internal fixation irritation. Hallux valgus surgery is not without risk and these findings could be useful in the informed consent process.</p> <p>Conclusions</p> <p>When combined the rotation scarf and Akin osteotomies are an effective treatment for hallux valgus that achieves good long-term correction with a low incidence of recurrence, footwear restriction or metatarsalgia. The nature of the osteotomies allows early return to normal shoes and activity without the need for postoperative immobilisation in a plaster cast.</p

Animal Models of Dyssynchrony

Cardiac resynchronization therapy (CRT) is an important therapy for patients with heart failure and conduction pathology, but the benefits are heterogeneous between patients and approximately a third of patients do not show signs of clinical or echocardiographic response. This calls for a better understanding of the underlying conduction disease and resynchronization. In this review, we discuss to what extent established and novel animal models can help to better understand the pathophysiology of dyssynchrony and the benefits of CRT