Effect of Sand Surface Training on Directed and General Co-contraction of Ankle Joint Muscles During Running

Background and Aims Foot overpronation is one of the most critical factors that cause musculoskeletal injuries and lead to greater mechanical loads in the lower limb structure. Sand is an unstable and unpredictable surface that has particular importance in human movement mechanics. The purpose of this study was to investigate the effect of sand surface training on directed and general co-contraction of ankle joint muscles in individuals with foot overpronation during running. Methods The present study was a randomized clinical trial type. Statistical samples of the present study included 15 males with foot overpronation in the control group and 15 males with foot overpronation in the intervention group. Individuals in the intervention group performed a sand surface training program consisting of continuous jogging, striding, bounding, galloping, and short sprints for 8 weeks. Tibialis anterior and gastrocnemius medialis muscles activity was evaluated by an 8-channel electromyography system with a surface electrode during running. A two-way ANOVA test was used for statistical analysis at the significant level P<0.05. Results The results demonstrated greater ankle-directed co-contraction in the push-off phase during post-test compared with the pre-test in the intervention group during training on sand (P=0.040). Other components of directed co-contraction in the different stages and general co-contraction in all phases did not demonstrate significant differences after sand training (P>0.05). Conclusion It seems greater ankle joint directed co-contraction in the push-off phase after training protocol reduced the risks of lower limb injuries and ankle instability in individuals with foot overpronation in this phase.

Biomechanics of lower limb in badminton lunge: a systematic scoping review

Background Badminton is a popular sport activity in both recreational and elite levels. A lot of biomechanical studies have investigated badminton lunge, since good lunge performance may increase the chances to win the game. This review summarized the current trends, research methods, and parameters-of-interest concerning lower-extremity biomechanics in badminton lunges. Methodology Databases including Web of Science, Cochrane Library, Scopus, and PubMed were searched from the oldest available date to September 2020. Two independent authors screened all the articles and 20 articles were eligible for further review. The reviewed articles compared the differences among playing levels, footwear designs, and lunge directions/variations, using parameters including ground reaction forces, plantar pressure distribution, kinematics, and kinetics. Results Elite badminton players demonstrated higher impact attenuation capability, more aggressive knee and ankle strategy (higher mechanical moment), and higher medial plantar load than amateur players. Footwear modifications can influence comfort perception and movement mechanics, but it remains inconclusive regarding how these may link with lunging performance. Contradicting findings in kinematics is possibly due to the variations in lunge and instructions. Conclusions Playing levels and shoe designs have significant effects on biomechanics in badminton lunges. Future studies can consider to use an unanticipated testing protocol and realistic movement intensity. They can study the inter-limb coordination as well as the contributions and interactions of intrinsic and extrinsic factors to injury risk. Furthermore, current findings can stimulate further research studying whether some specific footwear materials with structural design could potentially compromise impact attenuation, proprioception, and performance.

Effects of Upper-Limb, Lower-Limb, and Full-Body Compression Garments on Full Body Kinematics and Free-Throw Accuracy in Basketball Players

Compression garments can enhance performance and promote recovery in athletes. Different body coverage with compression garments may impose distinct effects on kinematic movement mechanics and thus basketball free-throw accuracy. The objective of this study was to examine basketball free-throw shooting accuracy, consistency and the range of motion of body joints while wearing upper-, lower- and full-body compression garments. Twenty male basketball players performed five blocks of 20 basketball free-throw shooting trials in each of the following five compression garment conditions: control-pre, top, bottom, full (top + bottom) and control-post. All conditions were randomized except pre- and post-control (the first and last conditions). Range of motion of was acquired by multiple inertial measurement units. Free-throw accuracy and the coefficient of variation were also analyzed. Players wearing upper-body or full-body compression garments had significantly improved accuracy by 4.2% and 5.9%, respectively (p < 0.05), but this difference was not observed with shooting consistency. Smaller range of motion of head flexion and trunk lateral bending (p < 0.05) was found in the upper- and full-body conditions compared to the control-pre condition. These findings suggest that an improvement in shooting accuracy could be achieved by constraining the range of motion through the use of upper-body and full-body compression garments.

Mechanisms to Attenuate Load in the Intact Limb of Transtibial Amputees When Performing a Unilateral Drop Landing

Individuals with unilateral transtibial amputations experience greater work demand and loading on the intact limb compared with the prosthetic limb, placing this limb at a greater risk of knee joint degenerative conditions. It is possible that increased loading on the intact side may occur due to strength deficits and joint absorption mechanics. This study investigated the intact limb mechanics utilized to attenuate load, independent of prosthetic limb contributions and requirements for forward progression, which could provide an indication of deficiencies in the intact limb. Amputee and healthy control participants completed 3 unilateral drop landings from a 30-cm drop height. Joint angles at touchdown; range of motion; coupling angles; peak powers; and negative work of the ankle, knee, and hip were extracted together with isometric quadriceps strength measures. No significant differences were found in the load or movement mechanics (P ≥ .31, g ≤ 0.42), despite deficits in isometric maximum (20%) and explosive (25%) strength (P ≤ .13, g ≥ 0.61) in the intact limb. These results demonstrate that, when the influence from the prosthetic limb and task demand are absent, and despite deficits in strength, the intact limb adopts joint mechanics similar to able-bodied controls to attenuate limb loading.

Kemampuan Kognitif Anak Usia Dini Dalam Pembelajaran Akuatik

The purpose of this article was to describe the cognitive abilities of early childhood in aquatic learning. This research uses a descriptive method. The subjects in this study were ten students of grade B children aged 5-6 years. The instrument in this study uses structured observation and field notes about children's cognitive ability which include class procedures, pool rules, playing rules, instruction language, and movement mechanics. The data analysis technique used is descriptive statistics. The results showed that the cognitive ability of children aged 5-6 years in the Pilot Laboratory of UPI Campus Tasikmalaya was still in the Start Developing category. This can be seen from the findings in the Tasikmalaya UPI Pilot Laboratory Kindergarten that the score of children's cognitive abilities was 44%.

The effects of a 4-week mesocycle of barbell back squat or barbell hip thrust strength training upon isolated lumbar extension strength

Objectives Common exercises such as the barbell back squat (BBS) and barbell hip thrust (BHT) are perceived to provide a training stimulus to the lumbar extensors. However, to date there have been no empirical studies considering changes in lumbar extension strength as a result of BBS or BHT resistance training (RT) interventions. Purpose To consider the effects of BBS and BHT RT programmes upon isolated lumbar extension (ILEX) strength. Methods Trained male subjects (n = 14; 22.07 ± 0.62 years; 179.31 ± 6.96 cm; 79.77 ± 13.81 kg) were randomised in to either BBS (n = 7) or BHT (n = 7) groups and performed two training sessions per week during a 4-week mesocycle using 80% of their 1RM. All subjects were tested pre- and post-intervention for BBS and BHT 1RM as well as isometric ILEX strength. Results Analyses revealed that both BBS and BHT groups significantly improved both their BBS and BHT 1RM, suggesting a degree of transferability. However, the BBS group improved their BBS 1RM to a greater degree than the BHT group (p = 0.050; ∼11.8 kg/10.2% vs. ∼8.6 kg/7.7%, respectively). And the BHT group improved their BHT 1RM to a greater degree than the BBS group (p = 0.034; ∼27.5 kg/24.8% vs. ∼20.3 kg/13.3%, respectively). Neither BBS nor BHT groups significantly improved their isometric ILEX strength. Conclusions The present study supports the concept of specificity, particularly in relation to the movement mechanics between trunk extension (including pelvic rotation) and ILEX. Our data suggest that strength coaches, personal trainers, and trainees can self-select multi-joint lower-body trunk extension exercises based on preference or variety. However, evidence suggests that neither the BBS nor BHT exercises can meaningfully increase ILEX strength. Since strengthening these muscles might enhance physical and sporting performance we encourage strength coaches and personal trainers to prescribe ILEX exercise.

#BlackLivesMatter: An Analysis of the Movement as Social Drama

Scholars agree that the United States is experiencing a new black civil and human rights movement called #BlackLivesMatter and that the Internet is pivotal to that movement. Protests in Ferguson, Missouri, and in Baltimore, Maryland, dominated national attention for months through 2014 and 2015. Protesters have successfully gained the attention of elite power brokers, a necessary step in the social movement process. #BlackLivesMatter has many insights to provide about mobilization, if researchers take black American discursive power and intellectual production more seriously as subjects of analysis. This article argues that a dramaturgy framework reveals important meaning making that occurs on the periphery of a social movement. In this periphery, my analysis shows that black social media publics are harbingers of racial progress. Introducing the concept of a Greek Chorus to the dramaturgy framework better clarifies the role that Twitter plays in the movement as a public space where outside observers negotiate their own meaning making surrounding the movement’s claims and strategies. Conceptualizing movement mechanics in this way provides a clearer understanding of the importance of digital media in the contemporary black civil rights movement without relying on technological determinism, reducing social media to a structural component of the movement, or undermining the importance of physicality to protest.