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This research project aims to conduct a systematic review of existing literature to investigate the impact of training interventions on hamstring adaptations for injury prevention in professional team-sport athletes. Specifically, the review will focus on the three primary risk factors associated with hamstring strain injuries: eccentric strength, fascicle length, and optimal angle of knee flexor muscles.

We evaluated sprint mechanical asymmetry in world-class competitors and evaluate whether inter-limb sex-based differences in sprinting mechanics exist. The eight finalists in the men’s and women’s 100 m events at the 2017 IAAF World Championships were studied. Five high-speed cameras (150 Hz) were used to capture two consecutive steps of the whole body between 47.0 m and 55.5 m from the start, while four additional cameras (250 Hz) focussed on the lower extremities. A total of 33 spatio-temporal, touchdown and toe-off joint angles, and horizontal and vertical foot velocity parameters were extracted through three-dimensional analysis. Group mean asymmetry scores were assessed using the symmetry angle (SA) where scores of 0% and 100% represent perfect symmetry and perfect asymmetry, respectively. Although considered generally low (SA < 3% for 22 out of 33 parameters), the magnitude of mechanical asymmetry varied widely between sprinters of the same sex. However, there was no mean SA scores difference between men and women for any stride mechanical parameters (all P≥0.064). Asymmetry scores were inconsistent between parameters and phases (touchdown vs toe-off instants), and sprinting mechanics were generally not related to asymmetry magnitudes. In summary, low to moderate asymmetry is a natural phenomenon in elite sprinting. Asymmetry was inconsistent between parameters and competitors during near maximum-velocity running, yet mean values for a given parameter generally did not differ between sexes. Sprinters’ performances were not related to their SA scores.

Measurements of muscle-tendon unit passive mechanical properties are often used to illustrate acute and chronic responses to a training stimulus. The purpose of this study was to quantify the inter-session repeatability of triceps surae passive stiffness measurements in athletic and non-athletic populations, with the view to discussing its usefulness both as a muscle-tendon profiling tool and a control measure for studies with multiple data collection sessions. The study also aimed to observe the effects of quiet standing on passive stiffness parameters. Twenty-nine men (10 cyclists, nine triathletes, 10 controls) visited the laboratory on three separate occasions, where passive stiffness tests were carried out using an isokinetic dynamometer and B-mode ultrasound. Participants were fully rested on two of the sessions and subjected to 20 min of quiet standing in the other. The passive stiffness assessment generally showed only moderate inter-session repeatability but was still able to detect inter-group differences, with triathletes showing higher passive stiffness than cyclists (p < 0.05). Furthermore, quiet standing impacted passive stiffness by causing a reduction in ankle joint range of motion, although mechanical resistance to stretch in the muscle-tendon unit at a given joint angle was relatively unaffected. These findings show that passive stiffness assessment is appropriate for detecting inter-group differences in the triceps surae and even the effects of a low-intensity task such as quiet standing, despite showing some inter-session variation. However, the inter-session variation suggests that passive stiffness testing might not be suitable as a control measure when testing participants on multiple sessions. peerReviewed

Colorectal cancer (CRC) is a leading nonfamilial cause of cancer mortality among men and women. Although various genetic and epigenetic mechanisms have been identified, the full molecular mechanisms deriving CRC tumorigenesis are not fully understood. This study demonstrates that cell adhesion molecule transmembrane and immunoglobulin domain containing 1 (TMIGD1) are highly expressed in mouse and human normal intestinal epithelial cells. TMIGD1 knockout mice were developed, and the loss of TMIGD1 in mice was shown to result in the development of adenomas in small intestine and colon. In addition, the loss of TMIGD1 significantly impaired intestinal epithelium brush border membrane, junctional polarity, and maturation. Mechanistically, TMIGD1 inhibits tumor cell proliferation and cell migration, arrests cell cycle at the G2/M phase, and induces expression of p(21CIP1) (cyclin-dependent kinase inhibitor 1), and p(27KIP1) (cyclin-dependent kinase inhibitor 1B) expression, key cell cycle inhibitor proteins involved in the regulation of the cell cycle. Moreover, TMIGD1 is shown to be progressively down-regulated in sporadic human CRC, and its downregulation correlates with poor overall survival. The findings herein identify TMIGD1 as a novel tumor suppressor gene and provide new insights into the pathogenesis of colorectal cancer and a novel potential therapeutic target.

We mapped structural and functional characteristics of muscle‐tendon units in a population exposed to very long‐term routine overloading. Twenty‐eight military academy cadets (age = 21.00 ± 1.1 years; height = 176.1 ± 4.8 cm; mass = 73.8 ± 7.0 kg) exposed for over 24 months to repetitive overloading were profiled via ultrasonography with a senior subgroup of them (n = 11; age = 21.4 ± 1.0 years; height = 176.5 ± 4.8 cm; mass = 71.4 ± 6.6 kg) also tested while walking and marching on a treadmill. A group of eleven ethnicity‐ and age‐matched civilians (age = 21.6 ± 0.7 years; height = 176.8 ± 4.3 cm; mass = 74.6 ± 5.6 kg) was also profiled and tested. Cadets and civilians exhibited similar morphology (muscle and tendon thickness and cross‐sectional area, pennation angle, fascicle length) in 26 out of 29 sites including the Achilles tendon. However, patellar tendon thickness along the entire tendon was greater (P < .05) by a mean of 16% for the senior cadets compared with civilians. Dynamically, cadets showed significantly smaller ranges of fascicle length change and lower shortening velocity in medial gastrocnemius during walking (44.0% and 47.6%, P < .05‐.01) and marching (27.5% and 34.3%, P < .05‐.01) than civilians. Furthermore, cadets showed lower normalized soleus electrical activity during walking (22.7%, P < .05) and marching (27.0%, P < .05). Therefore, 24‐36 months of continuous overloading, primarily occurring under aerobic conditions, leads to more efficient neural and mechanical behavior in the triceps surae complex, without any major macroscopic alterations in key anatomical structures.

Training for both sporting and military performance is common practice within army trainee populations, although it is currently unknown what effect this combination of training methods may have on the physical attributes required for overall physical preparedness. This study examined the effects of sport-specific training on general fitness in a professional military population. Four hundred and twenty-three Greek male army cadets completed a 12-week training regimen involving standard physical training (callisthenics, strength and endurance running exercises) and either general military training (GMT) or sport military training (SMT). A series of physical tests took place before and after the training period: a mile run, pull-ups, 50 m swim and an obstacle course run. Both the GMT and SMT groups showed significant (p

Racewalking is an unconventional form of competitive gait that elicits a unique loading profile on lower limb muscles and tendons. This study mapped the structural and mechanical properties of lower limbs in competitive racewalkers and made associations with World Athletics competition performance points. Fourteen international racewalkers (seven men, seven women) were recruited for this study. Static ultrasonography was used to quantify muscle and tendon morphological characteristics. An isokinetic dynamometer was used to measure passive musculotendinous stiffness of the triceps surae, isometric (seven knee/ankle angle combinations) and isokinetic (four angular velocities) strength parameters in the plantarflexors and dorsiflexors, and isokinetic knee flexion and extension strength at five angular velocities. Correlations were found between performance and fascicle length of gastrocnemius medialis (r = –0.569, p = 0.034), dorsiflexor strength at 120°/s (r = 0.649, p = 0.016) and knee flexor strength at 30°/s (r = 0.632, p = 0.020). No associations were found for isometric plantarflexion or passive stiffness properties. Overall, the study showed various morphological and mechanical properties are associated with performance in competitive racewalkers. These associations seem to be related to the specific and unique biomechanical characteristics of racewalking.

E-learning is becoming popular as it provides learners the flexibility, targeted resources across the internet, personalized guidance, and immediate feedback during learning. However, lack of social interaction, an indispensable component in developing some skills, has been a pain point in e-learning. We propose using Alexa, a voice-controlled Intelligent Personal Assistants (IPA), in e-learning to provide in-person practice to achieve some desired learning goals. With Alexa enabled learning experiences, learners are able to practice with other students (one role of Alexa) or receive immediate feedback from teachers (another role of Alexa) in an e-learning environment. We propose a configuration driven conversation engine, which can support instructional designers to create diverse in-person practice opportunities in e-learning. We demonstrate that learning designers can create an Alexa activity with a few configuration steps. We also share results on the effectiveness of an Alexa activity with formative assessment evaluation in real world applications.

Objectives: Achilles tendon rupture leads to functional impairments and these may be underpinned by morphological changes in the muscle-tendon unit. Functional performance of the injured limb will be impaired regardless of time since surgery and these impairments occur alongside changes in muscle-tendon morphology. Methods: Following operative treatment of Achilles tendon rupture and short term immobilisation, 12 patients completed a battery of tests during a single visit to the laboratory (performed an average of 4.4 ± 2.6 years post-surgery). Patients completed the Achilles’ tendon rupture score (ATRS), tests of ankle and hip range of motion (ROM) and ultrasound measurements of muscle-tendon architecture. Data on isokinetic (30 o/s, 60 o/s) plantar flexion strength, jumping performance and walking-running were also collected on the same visit. Percentage deficits were expressed relative to the non-injured limb and determined for statistical significance (p < 0.05). Relationships between outcomes measures and time since surgery were tested using Pearson’s correlation coefficients (p < 0.05). Results: The repaired limb showed a shorter muscle fascicle length (12.1-19.6%), increased fascicle pennation (18.0±22.14%) and reduced muscle thickness (9.1-20.1%) in the gastrocnemius and/or soleus along with greater tendon cross-sectional area (46.7±34.47%). Functionally, the repaired limb displayed lower countermovement jump height (-12.6±15.68%) and longer drop jump contact times (5.5±5.7%). Also, the repaired limb showed reduced hip internal-external ROM (6.3±8.2%) but no differences existed between limbs for plantar flexion ROM and strength or gait characteristics. Good ATRS outcomes were reported (mean: 87.9±16.2, range: 43-100) which related to time since surgery (r=0.79) but individual ATRS items did not correlate with corresponding objective measures. Conclusion: Plantar flexor atrophy following surgically treated Achilles tendon rupture is partially compensated for by remodelling of the fascicles however, impairments may still persist many years into the postoperative period although these may be more pronounced in high-velocity activities.

Bissas, A, Paradisis, GP, Nicholson, G, Walker, J, Hanley, B, Havenetidis, K, and Cooke, CB. Development and maintenance of sprint training adaptations: an uphill-downhill study. J Strength Cond Res XX(X): 000-000, 2020-We examined the development of performance adaptations resulting from an uphill-downhill training program and monitored the decline of adaptations during detraining. Twenty-eight men were randomly assigned to 1 of 2 sprint training groups who trained 3 times per week for 6 weeks and a control group (C). The uphill-downhill group (U+D) trained on an 80-m platform with 3° slopes, whereas the horizontal (H) group trained on flat track. Subjects were tested for maximal running speed (MRS), associated kinematics, and leg strength before and after training, with U+D subjects also tested after weeks 2 and 4 of training, and after a 3-week detraining period. The U+D group increased their MRS by 3.7% (from 8.75 ± 0.72 to 9.07 ± 0.64 m·s, p < 0.05), their stride rate by 3.1% (from 4.21 ± 0.21 to 4.34 ± 0.18 Hz, p < 0.05), and their knee extensors' maximum isometric force by 21% (from 2,242 ± 489 to 2,712 ± 498 N, p < 0.05) after training. The time course of changes showed declines for weeks 1-4 (1.4-5.1%), but an ascending trend of improvement compensated all losses by the end of week 6 (p < 0.05). During detraining, no decreases occurred. No changes were observed for the H and C groups. The minimum period to produce positive effects was 6 weeks, with a very good standard of performance maintained 3 weeks after training. U+D training will prove useful for all athletes requiring fast adaptations, and it can fit into training mesocycles because of its low time demands.

Isokinetic strength assessments are common outcome measures following operatively treated Achilles tendon (AT) ruptures. However, there is a lack of clarity on whether commonly reported outcome measures (such as peak joint moment) are sufficient to describe the extent of long-term functional deficits following AT rupture and repair. The present study conducted a comprehensive isokinetic evaluation of the Triceps surae complex in 12 participants who previously underwent AT rupture and repair. Testing occurred 4.4 (±2.6) years following surgery, and consisted of maximal isokinetic strength assessments of the plantarflexors at two angular velocities (30 and 60 °∙s-1) with the knee in flexed and straight positions. Differences between injured and non-injured limbs were tested through discrete and statistical parametric mapping analysis. Average joint moment showed significant main effects between injured and non-injured limbs, but common isokinetic parameters such as peak moment and angle of peak moment did not. The normalised moment curves showed a significant main effect of limb, angular velocity and knee joint position on joint moment throughout different portions of the range of motion. Temporal analysis revealed a significantly greater ability of the non-injured limb to sustain plantarflexor moments across a range of testing conditions. Participants who had undergone operative treatment of AT ruptures did not display inter-limb differences in discrete isokinetic strength outcomes that are often used in the literature. Instead, temporal analyses were required to highlight the reduced capacity of the injured limb to generate end-range joint moments and to sustain higher levels of joint moment for longer periods.

We aimed to compare the pregnancy rate from 1stTAI and 2ndTAI performed 24 days apart and pregnancy between cows that showed or not estrous on the end of 2nd TAI protocol. Were used 190 lactating cows (Angus: 114; Brangus: 53 and Santa Gertrudis: 23). On the first day of synchronization (D0), insertion of a new CIDR® (Zoetis) plus the 100µg of Cystorrelin®(Merial) treatment, on D7 25mg of Lutalyse® (Zoetis) and CIDR withdrawal. 72 hours after CIDR removal 1stTAI was performed plus GnRH treatment. After 14 days from 1stTAI, all the cows received an one time used CIDR. The pregnancy diagnosis was performed 22 days after 1stTAI, using a subjective visual evaluation of CL blood flow (BF). Pregnancy diagnosis was performed by ultrasonography Color Doppler (MicroMaxx®). Cows with an area of CL≥3cm² and/or ≥25% CL BF were diagnosed as pregnant and underwent CIDR removal without further treatment. Those diagnosed as non-pregnant underwent CIDR removal and received one Estrotect™ (Rockway-Inc.), 25mg of Lutalyse treatment and submitted to 2nd TAI 48h after CIDR removal (D24) plus the 100µg of Cystorrelin. On D31 considered pregnant cows on D22 were examined by US B-mode D31 to verify false positive and effective pregnancies. On D55, cows were submitted to US B-mode to verify the 2ndTAI pregnancy rate. Statistical analysis were performed using GLIMMIX procedure from SAS. The pregnancy on D22 was 48.5% (87/190) and the false positives were 14.9% (13/87). There was no difference on pregnancy 31 days after 1stTAI (38.9%; 74/190) vs. 2nd TAI (32.0%; 33/103; P = 0.24). Cows were more likely to be pregnant on D55 compared to cows that: showed Estrous: 42.9% (21/49) vs. No Estrous: 22.2% (12/54; P = 0.03). In conclusion, the pregnancy rates were the same at 1st to 2ndTAI. And cows that showed estrous had more pregnancy at 2ndTAI.

The aim was to investigate the kinematic factors associated with successful performance in the initial acceleration phase of a sprint in the best male athletes in the World at the 2018 World Indoor Athletics Championships. High speed video (150 Hz) was captured for eight sprinters in the men's 60 m final. Spatio-temporal and joint kinematic variables were calculated from the set position to the end of the first ground contact post-block exit (GC1). Normalised average horizontal external power (NAHEP) defined performance and was the dependent variable for a series of regression analyses. Clear relationships were found between GC1 NAHEP and 10-m time, 60-m time, change in velocity, acceleration and contact time in the first ground contact (r = –0.74, –0.64, 0.96, 0.91 and –0.56, respectively). Stepwise multiple linear regression of joint kinematic variables in the first ground contact revealed that trunk angle at take-off and thigh separation angle at take-off explained nearly 90% of variation in GC1 NAHEP (R2 = 0.89). The athletes’ projection at take-off with a forward leaning trunk and large thigh separation is characteristic therefore of excellent initial acceleration performance and this will be a good visual guide for technical coaching instruction. This was the first study of its kind to adopt such a research design in a World-class sample in a representative environment. Future studies that combine detailed kinematic and kinetic data capture and analysis in such a setting will add further insight to the findings of this investigation.

Adaptive learning has shown promise of meeting students' individual needs, and educators are interested in its affordances. However, little evidence-based practice exists to guide institutions and educators in using this pedagogical approach for teaching. In this presentation, we will share our experiences in exploring and implementing adaptive learning for first-year pharmacy students aiming to provide a tool that is adapted to students' individual learning needs. We will also share the lessons we have learned.