Comparative analysis of core muscle activation according to the use of props and the different knee angle during the modified Pilates Hundred.

BACKGROUND: There are not so many Pilates studies related to muscle activation. Since the effectiveness and efficiency of the Pilates Hundred to muscle activation has recently emerged, it is necessary to investigate the effects of the Pilates Hundred on core muscles. OBJECTIVES: The purpose of this study was to determine what difference occurs in the muscle activity, during the Pilates Hundred, to suggest the optimal props for muscle function improvement and then to provide data for the efficient exercise program. METHODS: Twenty-eight men in their twenties who were able to fully conduct Pilates Hundred. According to the difference between the small tool application (no prop: NP, soft ball mini: SB, Pilates ring: PR) and the knee joint angle (90° and 180°), muscle activations of rectus abdominis (RA), external oblique (EO), rectus femoris (RF), lateral muscle (vastus lateralis: VL), medial muscle (vastus medialis: VM), biceps femoris (BF), and semitendinosus (ST) were measured by the using surface electromyography (EMG) while different exercise conditions. RESULTS: During Pilates Hundred, the use of tools was found to be more effective in activating the core muscle (NP < SB < PR). During Pilates Hundred, 180° of knee angle had more influence on core muscle activation than 90°, and knee angle and props use showed an interaction for activating core muscles. CONCLUSION: The Pilates Hundred with PR and 180° knee angle intervention can increase core muscle activation, and this leads to effective Pilates exercise program for those who need to enhance core muscle volume and function and to rehabilitate core muscles.

Effects of applied swan pilates motions on upper body muscle activities.

BACKGROUND: There have been very few studies involving swan motion during pilates exercises, and there is also insufficient scientific evidence to support the fact that Pilates swan motion strengthens specific muscles. OBJECTIVES: Firstly, the purpose of this study was to evaluate the effect of 5 types Pilates swan motion (swan basic (SB), swan push-up (SP), swan holding posture (SH), form roller-based swan (SF), and circle-based swan (SC)) on muscle activity of deltoideus p. acromialis (DA), infraspinatus (IP), trapezius (TP), latissimus dorsi (LD), and erector spinae (ES). Secondly, the purpose of this study was to suggest an effective Pilates swan motion for strengthening muscle strength of each targeted muscle. METHODS: Twenty-four healthy men in their 20s participated and all participants were measured muscle activity in DA, IP, TP, LD, and ES muscles by electromyography (EMG) during 5 Pilates swan motions (SB, SP, SH, SF, & SC). The measured values were expressed as relative voluntary contraction (%RVC) values based on the SB. RESULTS: The %RVC values representing the muscle activity of DA and TP were significantly higher in SH and SP than in SC, SF, and SB (p < .001). The %RVC values of IP and LD were significantly higher in SH and SC than in SF, SP, and SB (p < .001). The %RVC value of ES was were significantly higher in SH than in SP, SC, SF, and SB (p < .001). CONCLUSION: The application of SP, SC, and SH Pilates swan motion is an effective method to activate the back muscles of the trunk.

Positive influence of aqua exercise and burdock extract intake on fitness factors and vascular regulation substances in elderly.

Health issues in elderly individuals are often complex and tend to lead to chronic diseases; such issues can be due to a decline in fitness resulting from lack of physical activity. Aqua exercise and burdock are positive effects on cardiovascular disease and vascular health. This study investigated the changes due to aqua exercise and burdock extract intake in senior fitness, prostaglandin I2 (PGI2), and thromboxane A2 (TXA2) in elderly women. Forty elderly women (65-80 years) volunteered for this study. After baseline measurements, participants were randomized into control (n = 8), aqua exercise (n = 11), aqua exercise and burdock extract intake combination (n = 11), and burdock extract intake groups (n = 10). The variables of senior fitness tests, PGI2 and TXA2 were measured in all participants before and after the 12-week study. Blood collections were carried out at the beginning- and the end of aqua exercise training. Muscular strength, endurance, flexibility, and cardiorespiratory endurance of aqua exercise and burdock extract intake group at post-test significantly increased compared to pre-test (p<0.05). There were no significant differences in PGI2 and TXA2 between pre- and post-training programs. In conclusion, our findings indicated that the aqua exercise and burdock extract intake improves senior fitness factors in elderly Korean women. Also, the program participation led to a balance between PGI2 and TXA2. Additionally, burdock extract intake may be useful in vascular health by playing a secondary role in disease prevention and health promotion.

Effects of aquarobic exercise and burdock intake on serum blood lipids and vascular elasticity in Korean elderly women.

BACKGROUND: The elderly's health issues are often complex and tend to lead to chronic diseases; such issues can be due to a fitness decline resulting from a lack of physical activities. The burdock root is a blood purifier, lymphatic system strengthener, and natural diuretic. The purpose of this study was to analyze the effects of aquarobic exercise and burdock intake on serum blood lipids and vascular elasticity in elderly women by implementing a 12-week program with these interventions. METHODS: Forty elderly female volunteer subjects aged 70 to 80years comprised the control group (n=8), aquarobic exercise group (n=11), aquarobic exercise and burdock intake combination group (n=11), and burdock intake group (n=10). The variables of serum blood lipids, and vascular elasticity were measured in all participants before and after the 12-week study. RESULTS: Total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) levels significantly decreased in the aquarobic exercise group and aquarobic exercise and burdock intake combination group (p<0.05, p<0.01, p<0.001). No statistically significant changes in pulse wave velocity were also found within or between the groups before and after participation in the 12-week program. CONCLUSIONS: Our findings indicate that aquarobic exercise and burdock intake improved the serum blood lipid levels and vascular elasticity of Korean elderly women. Additionally, burdock extract intake may be useful in vascular health by playing a secondary role in disease prevention and health promotion.

Wrist Resistance Training Improves Motor Control and Strength.

Chu, E, Kim, Y-S, Hill, G, Kim, YH, Kim, CK, and Shim, JK. Wrist resistance training improves motor control and strength. J Strength Cond Res 32(4): 962-969, 2018-The aim of this study was to investigate the effects of a 6-week direction-specific resistance training program on isometric torque control and isokinetic torque strength of the wrist joint. Nineteen subjects were randomly assigned to either the wrist training group (n = 9) or the control group (n = 10). The training group performed wrist exercises in 6 directions (flexion, extension, pronation, supination, radial deviation, and ulnar deviation), whereas the control group did not. Data were collected on the isometric torque control, 1-repetition maximum (1RM) strength, and isokinetic maximum torque (angular velocity of 60° per second wrist movements) before and after 6 weeks of resistance training and at 2-week intervals during training. The training group showed significant decreases in isometric torque control error in all 6 directions after 2 weeks of resistance training, whereas the control group did not show significant increase or decrease. After 4 weeks of training, the training group showed significant increases in maximum strength in all 6 directions as assessed by 1RM strength and isokinetic strength tests, whereas the control group did not show any statistically significant changes. This study shows that motor control significantly improves within the first 2 weeks of resistance training, whereas the wrist strength significantly improves within the first 4 weeks of resistance training. Based on the findings of this study, coaches and trainers should consider wrist resistance training to improve athletes' muscular strength and control of the wrist muscles.

Effect of Obesity on Blood Pressure and Arterial Stiffness in Middle-Aged Korean Women.

OBJECTIVES: Our study aims to provide basic scientific data on the importance of obesity management in middle-aged Korean women by analyzing its effects on blood pressure and arterial stiffness. In addition, we examined the correlations of these two parameters. METHODS: The study participants were 40 middle-aged female volunteers, who were classified into obesity group (n = 20) and normal weight group (n = 20). Statistical analysis was performed using independent t-test and the Pearson correlation coefficient was used to correlate blood pressure and arterial stiffness. RESULTS: This study evaluated the systolic blood pressure, diastolic blood pressure, and pulse wave velocity (PWV). These results were higher in the obesity group than the normal weight group. Furthermore, blood pressure and arterial stiffness (PWV, augmentation pressure) were static correlated. CONCLUSION: Obesity is closely related to blood pressure and arterial stiffness. Therefore, indices for blood pressure and arterial stiffness may play a vital role in predicting and preventing obesity and its sequelae.

Effect of the push-up exercise at different palmar width on muscle activities.

[Purpose] The purpose of the present study was to determine the effects of changes in palmar width on the muscle activities of the shoulder and truncus muscles during push-up exercise. [Subjects] Twelve healthy adult males participated in this study as subjects. [Methods] Push-up exercises were performed with three different palmar width in narrow (50%), neutral (100%), and wide positions (150%). We measured the muscle activities of the deltoideus p. acromialis, pectoralis minor, pectoralis major, serratus anterior, biceps brachii, triceps brachii, latissimus dorsi, and infraspinatus. [Results] Pectoralis minor, triceps brachii, and infraspinatus muscle activities were greater during push-ups performed with the 50% palmar width compared with the other palmar widths. Pectoralis major muscle activity was greater during push-ups performed with the 50% and 100% palmar widths compared with the 150% palmar width. Serratus anterior muscle activity was greater during push-ups performed with the 150% palmar width compared with the other palmar widths. [Conclusion] These results are expected to serve as reference materials for push-up exercise applications in training programs for truncus muscle strengthening or rehabilitation programs for scapula patients.

Tactile feedback plays a critical role in maximum finger force production.

This study investigates the role of cutaneous feedback on maximum voluntary force (MVF), finger force deficit (FD) and finger independence (FI). FD was calculated as the difference between the sum of maximal individual finger forces during single-finger pressing tasks and the maximal force produced by those fingers during an all-finger pressing task. FI was calculated as the average non-task finger forces normalized by the task-finger forces and subtracted from 100 percent. Twenty young healthy right-handed males participated in the study. Cutaneous feedback was removed by administering ring block digital anesthesia on the 2nd, 3rd, 4th and 5th digits of the right hands. Subjects were asked to press force sensors with maximal effort using individual digits as well as all four digits together, with and without cutaneous feedback. Results from the study showed a 25% decrease in MVF for the individual fingers as well as all the four fingers pressing together after the removal of cutaneous feedback. Additionally, more than 100% increase in FD after the removal of cutaneous feedback was observed in the middle and ring fingers. No changes in FI values were observed between the two conditions. Results of this study suggest that the central nervous system utilizes cutaneous feedback and the feedback mechanism plays a critical role in maximal voluntary force production by the hand digits.

Prehension synergy: use of mechanical advantage during multifinger torque production on mechanically fixed and free objects.

The aim of this study was to test the mechanical advantage (MA) hypothesis in multifinger torque production tasks in humans: fingers with longer moment arms produce greater force magnitudes during torque production tasks. There were eight experimental conditions: two prehension types determined by different mechanical constraints (i.e., fixed- and free-object prehension) with two torque directions (supination and pronation) and two torque magnitudes (0.24 and 0.48 N·m). The subjects were asked to produce prescribed torques during the fixed-object prehension or to maintain constant position of the free hand-held object against external torques. The index of MA was calculated for agonist and antagonist fingers, which produce torques in the same and opposite directions to the target torques, respectively. Within agonist fingers, the fingers with longer moment arms produced greater grasping forces while within antagonist fingers, the fingers with shorter moment arms produced greater forces. The MA index was greater in the fixed-object condition as compared with the free-object condition. The MA index was greater in the pronation condition than in the supination condition. This study supports the idea that the CNS utilizes the MA of agonist fingers, but not of antagonist fingers, during torque production in both fixed- and free-object conditions.

Multi-finger pressing synergies change with the level of extra degrees of freedom.

The purpose of this study was to test the principle of motor abundance, which has been hypothesized as the principle by which the central nervous system controls the excessive degrees of freedom of the human movements, in contrast to the traditional negative view of motor redundancy. This study investigated the changes in force stabilizing and moment stabilizing synergies for multi-finger pressing tasks involving different number of fingers. Twelve healthy subjects produced a constant pressing force while watching visual feedback of the total pressing force for the fingers involved in each task. Based on the principle of motor abundance, it was hypothesized that the multi-finger synergies for the total force stabilizing synergy and the total moment stabilizing synergy would be greater as the number of task finger increases. Force stabilizing and moment stabilizing synergies were quantified using the framework of the uncontrolled manifold analysis. It was found that strong force stabilizing synergies existed for all the finger combinations. The index of force stabilizing synergies was greater when the task involved more number of fingers. The index of moment stabilizing synergies was negative for the two-finger combination, representing moment destabilizing synergies. However, the index of moment stabilizing synergies was positive for three-finger and four-finger combinations, representing strong moment stabilizing synergies for these finger combinations. We interpret the findings as an evidence for the principle of abundance for stabilization of both, total force as well as total moment.

Physiological determinants of the candidate physical ability test in firefighters.

The purpose of this study was to examine the relative importance of physiological characteristics during firefighting performance, as assessed by the Candidate Physical Ability Test (CPAT). Subjects included career and volunteer firefighters aged 18-39 (N = 33). Upper- and lower-body strength, muscle endurance, lower body muscle power, body composition analysis, aerobic capacity, anaerobic fitness, and the heart rate (HR) and blood pressure response to stair climbing were assessed to determine the physiological characteristics of the subjects. To quantify firefighting performance, the CPAT was administered by members of the fire service. Absolute and relative mean power during the Wingate anaerobic cycling test (WAnT), relative peak power during the WAnT, and absolute maximal oxygen uptake (VO2max) were significantly higher in those who passed the CPAT (N = 18), compared to those who failed (N = 15; p < 0.01). Mean power during the WAnT, fatigue index during WAnT, absolute VO2max, upper body strength, grip strength, and the HR response to stair climbing were significantly related to CPAT performance time (p < 0.01). Absolute VO2max and anaerobic fatigue resistance during WAnT best predicted CPAT performance (Adj. R2 = 0.817; p < 0.001). Performance on the ceiling breach and pull was the only CPAT task that was not significantly related to the physiological characteristics assessed. Measures of anaerobic and cardiovascular fitness best predict overall CPAT performance, and individual task performance. Remedial programs aimed at improving firefighting performance should target anaerobic and aerobic fitness qualities.

Effects of training frequency on lumbar extension strength in patients recovering from lumbar dyscectomy.

OBJECTIVE: To determine the effects of lumbar extension exercise on strength, disability index, and pain scores in patients after lumbar discectomy surgery. DESIGN: Prospective comparative study. SUBJECTS: Forty patients experiencing a herniated disc at lumbar levels were divided into 4 subgroups for different training frequencies: twice/week (group 1), once/week (group 2), once/2 weeks (group 3), and no training (control). METHODS: After completing the initial 12-week training, all subjects participated in a 12-week follow-up training. RESULTS: Groups 1 and 2 showed significant increases in lumbar extension strength (26 Nm and 7 Nm, respectively), while group 3 and the control group showed significant decreases in lumbar extension strength. Groups 1 and 2 showed significant decreases in disability index (1.4 and 0.8 Oswestry Disability Index points, respectively), and group 1 showed significant decreases in back and leg pain scores (both 0.5 units on a 10-cm visual analog scale). CONCLUSION: Lumbar extension strength and disability index improve with training frequencies of once and twice per week, while back and leg pain improve with a training frequency of twice per week. The clinical importance of these improvements is questionable, as the scores were already very low after the discectomy and the magnitude of absolute improvements were small.

Handwriting: hand-pen contact force synergies in circle drawing tasks.

This study investigated synergistic actions of hand-pen contact forces during circle drawing tasks in three-dimensional (3D) space. Twenty-four right-handed participants drew thirty concentric circles in the counterclockwise (CCW) and clockwise (CW) directions. Three-dimensional forces acting on an instrumented pen as well as 3D linear and angular positions of the pen were recorded. These contact forces were then transformed into the 3D radial, tangential, and normal force components specific to circle drawing. Uncontrolled manifold (UCM) analysis was employed to calculate the magnitude of the hand-pen contact force synergy. Three hypotheses were tested. First, hand-pen contact force synergies during circle drawing are dependent on the angular position of the pen tip. Second, hand-pen contact force synergies are dependent on force components in circle drawing. Third, hand-pen contact force synergies are greater in CCW direction than CW direction. The results showed that the strength of the hand-pen contact force synergy increased during the initial phase of circle drawing and decreased during the final phase. The synergy strength was greater for the radial and tangential components as compared to the normal component. Also, the circle drawing in CW direction was associated with greater hand-pen contact force synergy than the CCW direction. The results of this study suggest that the central nervous system (CNS) prioritizes hand-pen contact force synergies for the force components (i.e., radial and tangential) that are critical for circle drawing. The CNS modulates hand-pen contact force synergies for preparation and conclusion of circle drawing, respectively.

Effects of aquatic backward locomotion exercise and progressive resistance exercise on lumbar extension strength in patients who have undergone lumbar diskectomy.

OBJECTIVE: To compare the effects of aquatic backward locomotion exercise and progressive resistance exercise with a machine on lumbar extension strength in patients who have undergone diskectomy for a lumbar disk herniation. DESIGN: Prospective comparative study. SETTING: Department of Kinesiology at a state university. PARTICIPANTS: Male patients (N=30) with disk herniation at spinal levels L3 to S1 completed this study as subjects. INTERVENTION: After the diskectomy for a lumbar disk herniation, all patients had 6 weeks of rest time. At the end of the rest period, the aquatic backward locomotion exercise and progressive resistance exercise groups, respectively, started first 6 weeks of underwater training and lumbar extension training twice per week. After completion of the first 6-week training, subjects participated in a second 6-week training. After the whole 12-week training, subjects had no training for 6 weeks (detraining) and a follow-up 6-week training (retraining). The control (CON) group did not undergo any training. MAIN OUTCOME MEASURES: For each test, maximum voluntary isometric lumbar extension strength was measured in 7 trunk positions (72 degrees , 60 degrees , 48 degrees , 36 degrees , 24 degrees , 12 degrees , and 0 degrees of the trunk angle). RESULTS: The progressive resistance exercise and aquatic backward locomotion exercise groups showed increases in lumbar extension strength after the first 6-week training, although they were not statistically different from the CON group. After a second 6-week training, the progressive resistance exercise and aquatic backward locomotion exercise groups showed statistically significant increases in their strength levels as compared with the CON group. After the detraining period, the strength levels of the progressive resistance exercise and aquatic backward locomotion exercise groups did not statistically differ from the CON group. After the retraining period, the progressive resistance exercise and aquatic backward locomotion exercise groups showed increases in their strength levels, which were different from that of the CON group. CONCLUSIONS: The results obtained suggested that the aquatic backward locomotion exercise is as beneficial as progressive resistance exercise for improving lumbar extension strength in patients after lumbar diskectomy surgery.

Prehension synergy: effects of static constraints on multi-finger prehension.

Previous studies have shown that the interactions of human hand digits are influenced by internal constraints, i.e., biomechanical and central constraints. However, little is currently known about the influence of externally imposed mechanical constraints on multi-finger behavior. This study investigates maximal digit force production during fixed object and free object prehension in statics. The results from the fixed object prehension indicated that the closer the non-task finger was positioned to the task finger, the greater the force produced by the non-task finger, which supports the proximity hypothesis. Conversely, the non-task fingers with longer moment arms showed greater force production during free object prehension, which supports the mechanical advantage hypothesis. During the free object prehension, equal and opposite torques were produced by the digit normal forces and tangential forces, while this phenomenon was not observed in the fixed object prehension. The results also showed that the thumb normal force had a positive linear relationship with task-finger normal forces during fixed object prehension while the thumb normal force remained constant during free object prehension tasks. We concluded that the CNS employed different strategies when different sets of internal and external constraints are provided during multi-digit prehension tasks.

Finger force enslaving and surplus in spinal cord injury patients.

This study investigated the phenomena of finger enslaving, involuntary finger actions by non-intended fingers, and force deficit, smaller maximum force by all four fingers than the sum of individual finger maximum forces in individuals with cervical spinal cord injuries (SCI). A total of 16 subjects participated in this study: 8 with a cervical spinal cord injury and 8 controls. Each of the injured subjects had one paralyzed finger. The results showed that the efforts to produce force using any individual finger induced force production in all other fingers, suggesting finger force enslaving. The maximum force during the four-finger task was greater than the sum of the individual finger forces during single-finger tasks in the SCI group, which was reflected by positive force deficit, "force surplus". One may utilize these findings for rehabilitation of paralyzed fingers caused by cervical spinal injuries.