The Cactus And The Rose : A Western Idyl

https://digitalcommons.library.umaine.edu/mmb-vp/1140/thumbnail.jp

Exploring tissue engineering

In this Creative Inquiry, we have two main projects. Our first project aims to improve the cell culture process by eliminating the need for trypsin, an enzyme that dissociates cells from the surfaces they grow on, but also compromises cell membrane integrity and can kill cells over time. This will be done by growing cells on solar panels. Induced current via light exposure will repel the proteins from the surface so that the cells can be collected. The second project aims to determine the most viable and reproducible method of culturing cells in 3D geometry. Initial studies were done on fibroblast cells and further studies will focus on mimicking tumors. Various culturing environments, cell lines, and culturing surfaces (such as non-adhering surfaces) will be done to alter the geometries, size, and composition of the 3D geometries. The first project would be useful for pharmaceutical companies who culture large volumes of cells and for researchers who wish to study specific cell membrane proteins while the second project has applications in cancer research

Hip abductors and thigh muscles strength ratios and their relation to electromyography amplitude during split squat and walking lunge exercises

Background: The hip abductors (HAB), quadriceps (Q) and hamstrings (H) reciprocal strength ratios are predictors of electromyography (EMG) amplitude during load carrying walking at moderate intensity. Therefore, these strength ratios might predict also the EMG during the exercises as walking lunge (WL) or split squat (SSq) at submaximal intensity. Objective: To determine whether the EMG amplitude of vastus mediali (VM), vastus laterali (VL), biceps femoris (BF) and gluteus medius (Gmed) is associated with muscle strength ratio during SSqs and WLs. To determine whether the EMG amplitude differs between individuals with HAB/H ratio above and below one and between individuals with H/Q or HAB/Q ratio above and below 0.5 during SSqs and WLs. Methods: 17 resistance-trained men (age 29.6 ± 4.6 years) with at least 3 years of strength training performed in cross-sectional design 5 s maximal voluntary isometric contractions (MVIC) on an isokinetic dynamometer for knee extension, knee flexion, and hip abduction. The MVIC was used to normalize the EMG signal and estimate the individual strength ratios. Than participants performed WL and SSq for a 5 repetition maximum, to find out muscle activity at submaximal intensity of exercise. Results: The H/Q ratio was associated by Kendall’s tau (τ) with VM (τ = .33) and BF (τ = -.71) amplitude, HAB/Q ratio was associated with BF (τ = -.43) and Gmed (τ = .38) amplitude, as well as HAB/H was associated with VM (τ = -.41) and Gmed (τ = .74) amplitude. ANOVA results showed significant differences between SSq and WL (F(4, 79) = 10, p \u3c .001, ηp2 = .34) in Gmed amplitude, where WL resulted in higher Gmed amplitude compared to SSq. Other significant differences were found between H/Q groups (F(4, 29) = 3, p = .04, ηp2 = .28) in VM and Gmed amplitude, where group with H/Q \u3e 0.5 showed higher VMO amplitude and lower Gmed amplitude. Furthermore, significant difference was found for HAB/H groups (F(4, 29) = 4, p = .02, ηp2 = .34) in VM amplitude, where group with HAB/H \u3c 1 showed higher VM amplitude. Conclusions: The ratios of HAB, H and Q are able to predict Gmed, VM and BF activity during WL and SSq. WL resulted in higher activity level of Gmed than SSq, because WL includes the impact forces as part of lunge movement. WL should be used in resistance-training programme, if the strengthening of Gmed or VM is the aim

A Systematic Review of Spatial Differences of the Ball Impact within the Serve Type at Professional and Junior Tennis Players

Since the flat serve (FS) minimizes the ball spin and kick serve (KS) combined topspin and sidespin, this systematic review aimed to explore the ball impact location (BI) within the FS and KS at the professional men, junior men, and women tennis players. The PRISMA guideline was used, and the original articles were searched in Scopus, Web of Science, and PubMed. The means and standard deviations computed from the distance of BI from the origin within the FS and KS on the x, y, and z axes (global coordinate system) were normalized by the participants’ height and weighted by the number of participants in one-way ANOVA. Ten articles with a pooled sample of 133 males and 51 females aged 11–25 were included. The professional men had more stable BI on the x-axis within the FS by 56% (p < 0.001), within the KS by 58% (p < 0.001), and on the y-axis within the KS by 90% (p < 0.001) than junior men. The professional and junior men had the BI more leftwards from the origin on the x-axis within the KS by 188% (p < 0.001) and 88% (p < 0.001), respectively than within the FS

Performance Level and Strike Type during Ground and Pound Determine Impact Characteristics and Net Force Variability

The evaluation of strike impact is important for optimal training, conditioning and tactical use. Therefore, the aim of this study was to evaluate ground and pound strikes, in terms of net force variability, across genders and performance levels. Eighty-one participants, professional men (n = 8, 37 ± 6 years, 195 ± 7 cm, 113 ± 27 kg), advanced men (n = 47, 26 ± 8 years, 180 ± 7 cm, 76 ± 11 kg), and advanced women (n = 26, 21 ± 1 years, 167 ± 6 cm, 61 ± 7 kg) performed three strikes from a kneeling position into a force plate on the ground. The elbow strike resulted in the highest impulse and the palm strike in the highest peak force for all three categories. These results support the recommendation that has previously been made to teach the palm strike to beginners and advanced tactical and combat athletes. The direct punch and elbow strike net force were characterized by a double peak curve, where the first peak variability explained 70.2–84% of the net force. The second peak was pronounced in professional men during elbow strikes, which explained 16% of net force variability. The strike type determines the impact net force and its characteristics, where palm strike is typical by highest peak impact tolerance and elbow strike by double force peak with high net force impulse

Arm - Leg coordination profiling during the dolphin kick and the arm pull-out in elite breaststrokers

In breaststroke races, the dolphin kick could finish before, at the same time, or during the arm pull-out, but it is unclear how swimmers perform this technique. The aim of this study was to investigate whether swimmers glide between the dolphin kick and arm pull-out, favour continuity or even overlap those two phases, as it would impact the active underwater sequence. Fourteen international and national male swimmers performed 100-m breaststroke with all-out effort in a pre-calibrated 25 m swimming pool. A multi-camera system tracked the head of the swimmers. Key points of the active underwater sequence were obtained from notational analysis. A hierarchical cluster analysis identified three coordination profiles. All swimmers started their dolphin kick before the arm pull-out. However, one swimmer started the arm pull-out before the end of the dolphin kick, seven swimmers started the arm pull-out after the end of the dolphin kick, and four swimmers synchronised the beginning of the arm pull-out and the end of the dolphin kick, while two other swimmers mixed two coordination profiles among the start and the three turns. Those different profiles allow achieving similar performance outcome, suggesting individual training regarding the underwater phase

Effect of strength training programs on front push kick dynamics and kinematics

Background and Study Aim: The general fitness requirements for any combat activity include the flexibility, speed, power, muscular endurance, aerobic capacity, muscular strength, agility, balance, coordination, and body composition. In addition, the development of these fitness component should support and not disrupt the development and practice of combat techniques The aim of this study was knowledge about the effects of two programs of strength training on front push kick dynamics and kinematics across different loading conditions (no-load up to 45kg of external load) in professional soldiers. Material and Methods: Sixteen professional military personnel were randomized into two groups who performed an 8-week intervention program focused either on functional training with a core emphasis (FCE: 26.8 ±10.1 years, 84.2 ±5.4 kg, 181.1 ±6.4 cm) or traditional strength preparation (TSP: 26.8 ±10.1 years, 84.2 ±5.4 kg, 181.1 ±6.4 cm). Both groups performed 5 front push kicks into a force plate across 5 different loading conditions and forces and kinematics were measured. Results: The main differences in the performance of the front push kicks after FCE were that impulse increased by 16% and the impact time of the front kicks were prolonged by 10% whereas after TSP the peak force was increased by 20% and the angular velocity of the knee by 13%. Both training programs promoted changes in the coordination of movement as quantified by principal component analysis. Conclusions: The FCE should be included in training close combat to increase impulse of the front push kick and TSP should be included to increase the peak force and the angular velocity of the knee. The combination of FCE and TSP should be used in training as both could improve kicking performance

A Systematic Review of Dynamic Forces and Kinematic Indicators of Front and Roundhouse Kicks across Varied Conditions and Participant Experience

Impact force and maximum velocity are important indicators of kick efficiency. Therefore, this systematic review compared the front kick (FK) and roundhouse kick (RK), including their impact force, maximum velocity, angular velocity, and execution time, considering various target types and experience levels. Following PRISMA guidelines, the Web of Science, SportDiscus, and PubMed were systematically searched for articles published from January 1982 to May 2022. Normalized kicking values were compared using one-way ANOVA. Eighteen articles included FKs (sample: 113 elite men, 109 sub-elite men, and 46 novices), and twenty-five articles included RKs (sample: 238 elite men, 143 sub-elite men, and 27 novice men). The results indicate that the impact force of the FK were 47% (p < 0.01), 92% (p < 0.01), and 120% (p < 0.01) higher than those of the RK across novice, sub-elite, and elite groups, respectively. Moreover, the maximum foot velocity of the RK was 44% (p < 0.01) and 48% (p < 0.01) higher than that of the FK for the sub-elite and elite groups, respectively. Furthermore, the elite group had 65% (p < 0.01) higher knee extension angular velocity with the RK than with the FK and 138% (p < 0.01) higher hip extension angular velocity with the FK than with the RK. In summary, the findings suggest that the FK is more effective in generating forceful kicks, while the RK has the potential for rapid execution