OBJECTIVE: Performing back squats with elastic bands has been widely used in resistance training. Although research demonstrated greater training effects obtained from adding elastic bands to the back squat, little is known regarding the optimal elastic resistance and how it affects neuromuscular performance. This study aimed to compare the force, velocity, power, and muscle activity during back squats with different contributions of elastic resistance.
METHODS: Thirteen basketball players performed 3 repetitions of the back squat at 85% of 1-repetition maximum across 4 conditions: (1) total load from free weight and (2) 20%, (3) 30%, and (4) 40% of the total load from elastic band and the remaining load from free weight. The eccentric and concentric phases of the back squat were divided into upper, middle, and bottom phases.
RESULTS: In the eccentric phase, mean velocity progressively increased with increasing elastic resistance, and muscle activity of the vastus medialis and rectus femoris significantly increased with the largest elastic resistance in the upper phase (P ≤ .036). In the concentric phase, mean power (P ≤ .021) and rate of force development (P ≤ .002) significantly increased with increasing elastic resistance. Furthermore, muscle activity of the vastus lateralis and vastus medialis significantly improved with the largest elastic resistance in the upper phases (P ≤ .021).
CONCLUSIONS: Velocity, power, rate of force development, and selective muscle activity increased as the elastic resistance increased in different phases during the back-squat exercise.

[Purpose] To investigate the effects of exercise using a modified elastic band with a coconut shell on leg muscle strength and balance in older adults. [Participants and Methods] The study consisted of 30 participants aged 60 years and older. The participants were randomly assigned to either the exercise (n=15) or control groups (n=15). The exercise group used a modified elastic band with a coconut shell three days a week for four weeks. Both groups received a single educational session on fall prevention after a baseline assessment. The Functional Reach Test (FRT) and Timed Up and Go Test (TUG) were used to assess balance, respectively. The 30-second chair stand test (30CST) was also used to measure leg strength. All outcome parameters were measured at the beginning of the study, immediately after a single exercise session, and after four weeks of exercise. [Results] The FRT and 30CST significantly increased in the exercise group after four weeks of exercise. The TUG significantly decreased in the exercise group after completing the program. [Conclusion] This study demonstrated that exercise using a modified elastic band with a coconut shell could effectively improve leg muscle strength and balance in older adults.

Existing elastic band materials for sports rehabilitation equipment have some deficiencies in strength, flexibility and durability, and need to be further improved. Therefore, the aim of this paper is to modify elastic bands using a conjugated material, carbon nanotubes, to improve the strength, flexibility and durability of elastic bands. In this paper, conjugated carbon nanotubes were prepared, and their elastic bands were strengthened and toughened by solvent, dispersant and functionalizer respectively under tensile testing machine and scanning electron microscope. Then the application effect of elastic band modified by conjugated materials in exercise rehabilitation was analyzed experimentally. The experimental results show that the strength of the elastic bands modified with carbon nanotubes is in the optimal range for sports rehabilitation, and the elongation at break of the test elastic band toughness index was also higher than that before modification, all of which were more than 90%. The recovery time of the elastic band after modification was long; the elastic retention rate was high, and the deformation was not easy. The satisfaction rate of different grades of elastic bands after modification was particularly high, which was not less than 95%. The research and application of elastic band modification based on conjugated material carbon nanotubes is very important for training and treatment in sports rehabilitation, which can provide better support and stability.

Background: During the repetitive execution of the swimming strokes, the muscles responsible for the internal rotations of the shoulders tend to become stronger compared to the muscles that oppose these movements. The aim of this study was to analyse the effect of a strengthening program for the shoulder rotator muscles using elastic band exercises in a diagonal Kabat pattern (D2 for flexion) in swimmers, to develop an effective, quick and easy-to-implement protocol for preventive training routines. Methods: A randomized controlled trial design was carried out. Internal and external rotation range of movement, isometric strength of the muscles responsible for internal and external rotation of the shoulder, scapular movements, was measured at the beginning of the study and after 8 weeks post-intervention. A total of 22 male swimmers participated in the study and were randomly assigned to either an experimental group (n = 11) or a control group (n = 11). The experimental group underwent a 8-week shoulder-strength program using elastic bands, while the control group focused on aquatic training. Results: The strength-training program resulted in an improvement in the isometric strength of the muscles responsible for external rotation and a better balance between the shoulder rotator muscles in the experimental group. However, these improvements have not been significant (p > 0.05). Conclusion: The strengthening exercise program showed minimal improvement in shoulder rotation strength and range of motion. These findings suggest that the prescribed shoulder-strengthening exercise could be a quick-beneficial dry-land training option to improve external rotation shoulder strength or range of motion, but more studies with larger sample sizes and more weeks of treatment are needed to determine the efficacy of this protocol.

Background: Explosive and fast body movements, sprints, jumps and quick changes of direction, which are characteristic of the football training, place considerable strain on the hamstring muscles. Due to the high occurrence of hamstring injuries, new preventive strategies are required that focus on high-velocity training. The purpose was to assess the effectiveness of high-velocity elastic-band training in reducing the occurrence of hamstring injuries in football players. Methods: Male football players from 15 teams (n = 319) playing in national competitions participated in this study. The players were involved in a 5-week exercise period in either the intervention group (INT) or the control group (CON), with a follow-up period of ∼4 months where hamstring injuries and exposure time were recorded. The INT group had two to three sessions per week of elastic-band training with low-load, high-velocity leg curls while lying prone; the CON group performed self-paced football-specific drills. Results: The incidence rate of hamstring injuries was 6.5% in the INT group (8 out of 123 players) and 9.2% in the CON group (18 out of 196 players). Although the INT group showed almost 1/3 reduction in hamstring injury incidence compared to the CON group, the difference was not statistically significant (p > 0.05). Moreover, no differences (p > 0.05, odds ratio [OR] = trivial-to-small) in distribution between the groups were found in hamstring injury characteristics (leg dominance and mechanism) except for the distribution of injuries that occurred during matches or training (p = 0.036; OR = 6.14, moderate). Conclusion: The program of high-velocity elastic-band training did not prove to be effective in preventing hamstring muscle injuries in football players despite displaying some positive indications that could be considering when creating injury prevention programs.

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The aim of this study was to investigate the differences in neuromuscular performance between variable resistance training and constant resistance training within complex training. Twenty-one well-trained collegiate basketball players were randomly assigned to either an experimental group (variable resistance training) or a control group (constant resistance training) and completed a twice weekly training program over an 8-week period. Training programs were the same except that the experimental group included variable resistance via elastic bands (40% of the total load). Maximum strength, vertical jump, horizontal jump, and sprint performance were assessed pre- and post-intervention. Both groups demonstrated significant increases in the back squat 1RM (experimental group +36.5% and control group +32.3%, both p < 0.001), countermovement jump (experimental group +12.9%, p = 0.002 and control group +5.6%, p = 0.02), and squat jump performance (experimental group +21.4% and control group +12.9%, both p < 0.001), whereas standing broad jump performance improved only in the experimental group (+2.9%, p = 0.029). Additionally, the experimental group showed significant improvement in the squat jump (p = 0.014) compared with the control group. However, no statistically significant differences were found between groups for countermovement jump (p = 0.06) and sprint performance at 10 m (p = 0.153) and 20 m (p = 0.076). We may conclude that both training modalities showed similar improvements in maximum strength. Performing variable resistance training within a complex training program is more efficient to enhance selective power performance in well-trained collegiate basketball players.

With continuous development of artificial intelligence technology, strain sensors have attracted widespread attention. In this work, a novel high-performance wearable strain sensor is prepared by using a kind of ultra-stretchable, super-hydrophobic and high-conductive composite. The preparation process is as follows, i.e., using common elastic band (EB) as the polymer matrix, nano carbon black (CB) and carbon nanotubes (CNTs) as mixed conductive filler, and then modified by polydimethylsiloxane (PDMS) to obtain the PDMS/(CB + CNTs)/EB composite for assembling assemble flexible wearable strain sensors. Experimental results reveal the following excellent properties: 1) The composite exhibits excellent mechanical properties and super-hydrophobicity, i.e., the tensile strength is up to 996.5%, and the elastic modulus and tensile strength increase 49.2% and 59.2%, compared with pristine EB; 2) The composite strain sensor exhibits high sensitivity (the gauge factor reaches up to 648.83 under strain range of 979.9-996.5%), and it still shows stable performance after 3000 cycles tests (100% strain); 3) It is a well candidate to be used for monitoring human body motions including large and subtle body movements; 4) The composite sensor also has advantages of easy access of raw materials, simple preparation, easy mass production and relatively low production cost, showing a broad application prospect in wearable electronic products.

UNASSIGNED: Many studies show that aerobic exercise combined with resistance training is beneficial for patients with chronic heart failure (CHF). The benefits of traditional Chinese exercise Baduanjin combined with an elastic band in this population are not known. To evaluate the effects of Baduanjin in conjunction with an elastic band on exercise capacity, physical function, muscle strength of the upper and lower extremities, quality of life (QoL), and exercise self-efficacy among CHF patients in a home-based setting.
UNASSIGNED: A prospective randomized controlled trial was conducted in this study. A total of 136 CHF patients were randomly assigned to the exercise or the control group. Chronic heart failure patients in the exercise group received Baduanjin combined with elastic band and CHF community care, while those in the control group accepted CHF community care. The duration of the interventions was 24 weeks. The measured outcomes included exercise capacity, physical function, muscle strength of the upper and lower extremities, QoL, and exercise self-efficacy. A generalized estimating equation model was employed to examine the effects of Baduanjin combined with the elastic band on the outcome variables. Chronic heart failure patients showed significant improvements in physical performance testing (PPT) (P = 0.023), 30-s arm curl test (30ACT) (P = 0.035), 10 sit-stand-to-sit tests (STS10) (P = 0.017), 6-min walk test (6MWT) (P < 0.001), QoL (P < 0.001), and exercise self-efficacy (P = 0.009) in the exercise group, while these variables did not differ in the control group. There were also significant differences in these variables between the two groups at Weeks 12 and 24 (P < 0.05). There were significant group-by-time interactions in the exercise group, with enhancements in PPT (F = 5.40, P = 0.032), 6MWT (F = 9.04, P < 0.001), muscle strength in the 30ACT and STS10 (F = 5.32, P = 0.037; F = 6.69, P = 0.005), QoL (F = 6.69, P < 0.001), and self-efficacy (F = 4.60, P = 0.038) revealed in CHF patients in this group from baseline to Week 24.
CONCLUSIONS: Baduanjin combined with elastic band exercise may improve exercise capacity, physical function, muscle strength, QoL, and exercise self-efficacy for CHF patients in a home-based setting, which may be a complementary exercise model for home-based CHF patients who are clinically stable and cannot participate in centre-based exercise-based cardiac rehabilitation programmes.

Quantifying training variables of a physical exercise modality is essential for an appropriate dosage. In training with elastic bands, time under tension (TUT) and force represent the duration and intensity of this force-training modality. The aims of this study were to evaluate the degree of compliance to TUT prescription for three different scenarios of two exercises and the comparison of the force values obtained versus the estimate values. A total of 29 healthy volunteers were evaluated in a clinical environment under controlled conditions in 3 different scenarios (different velocities or ROMs) of both shoulder abduction and knee extension in 2 sets of 10 repetitions per scenario within a single session. Concentric and isometric phases showed a higher degree of compliance for their TUTs than the eccentric phase TUTs for all scenarios of both exercises, whereas the degree of compliance was higher for the total TUT than for the phases\' TUTs. Additionally, the eccentric phase showed a general tendency to develop for longer time periods than prescribed, whilst the fast scenario showed a higher degree of compliance for isometric phase TUTs and total TUTs than the extant two scenarios in both exercises. On the other hand, the force of the elastic bands tends to be overestimated according to the estimates of the manufacturers. These findings, both those related to the degree of compliance with TUTs and the force analysis, can be used by physiotherapists and other exercise professionals as a reference to achieve a good dosage of routine exercises with elastic bands.