Leg Squat Research Articles

Contribution of squat jump, leg squat, and walking lunge to mawashi geri kicking ability skills

Muscle explosiveness is a physical component that contributes from technical ability to karate ability. The kicking technique in karate is a very important skill in attacking movements. It is necessary to provide training so that muscle explosive power, especially in the legs, increases so that technical ability can increase. Squat jump exercises, leg squats, and walking lunges are forms of exercise that can increase muscle explosive power and the ability of karate kicks. This study aimed to determine the contribution of squat jump exercises, leg squats, and walking lunges to the ability to kick in karate. The subjects of this study were 27 female Karate Dojo athletes, the subject collection technique was total sampling by recruiting all 27 female athletes. The instruments used in this study were for initial and final test measurements using Mawashi Geri's kick ability test. Data analysis using ANOVA test and statistical prerequisite test using SPSS 25. The results of this study from the results of data analysis with a comparative hypothesis test between posttest values showed a calculated t value < a significant level of 0.05, which means that the provision of squat jumps, leg squats, walking lunges significantly contributed to Mawashi Geri's kicking ability. The conclusion of the results of this study explains that leg muscle power training has contributed to Mawashi Geri's kicking ability, especially in walking lunges training the results of the research are very significant.

Patients with Anterior Cruciate Ligament Injuries Depend on Visual Information for Multi-Joint Coordination During Single- Leg Squats

Patients with Anterior Cruciate Ligament Injuries Depend on Visual Information for Multi-Joint Coordination During Single- Leg Squats

Effects of Single Leg Jumping and Squat Training in Various Directions on Balance Ability in Healthy Individuals

Effects of Single Leg Jumping and Squat Training in Various Directions on Balance Ability in Healthy Individuals

Repetitive trauma-induced extra-nuchal-type fibroma.

A nuchal-type fibroma is a rare, benign fibrous tumour that typically occurs in the posterior neck along the midline, but can occur in extra-nuchal locations, most commonly in the back, shoulder and face. We present a biopsy-proven case that arose as a result of heavy gym-related activities. In particular, a heavy barbell was rested on his vertebral prominence at the level of C7/T1 during leg squatting. Repetitive trauma as a cause for extra-nuchal-type fibromas has been sparsely reported, but we suggest that sustained high pressure is an additional required feature. Although this lesion was in the posterior neck, it was contained entirely within the subcutaneous tissues without involvement of the nuchal ligament. Hence, it was considered an extra-nuchal fibroma. A description of key ultrasound and MRI imaging characteristics are provided to assist in making the diagnosis, along with a review of the current literature and a discussion of differential diagnoses.

Effect of Handedness and Footedness on Some Motoric Characteristics in Amateur Soccer Players

The present study aims to compare the strength of right and left legs and reaction times of soccer players depending on their hand and foot preferences. The study included 92 volunteers chosen from amateur soccer players. The measurements conducted on the subjects were anthropometric characteristics, foot reaction times (sound, light) and right and left foot squat parameters. The t-test was used for statistical procedures. Among the amateur soccer players who participated in this study, it was found that 19.57% used left hand and 67.39% used right hand as preferred. Soccer players using both hands equally were found with a rate of 13.4%. In terms of foot preference, it was found that 22.83% of the participants used left foot and 43.48% of the participants used right foot as preferred. The soccer players using both feet equally was found as 33.70%. No significant difference was found between right handers and left handers in reaction time measurements when the soccer players were grouped by hand preference. When compared with left footed players (0.29 sec), only the right foot sound reaction time of right footed players was significantly shorter (0.21 sec) at p<. 05 level. Statistically significant correlation was found between soccer players’ hand and foot preference at a level of p< 0.01. Left footed players had significantly higher left leg mean squat (37.19 kg) when compared with right footed players (32.27 kg). No significant difference was found between right footed (35.36 kg) and left footed (33.98) subjects in terms of mean of right leg squat. Conclusion: According to the hand preference, the proportion of those who use equally two feet increased. Reaction times and force's squat of the dominant hands and feet were better. Training programs for soccer players planned according to individual characteristics including footedness may result in performance increase and decrease in injury as a result of reduced strength and reaction time asymmetry between legs and arms.

A Comparative Study of Different Types of Warm-up Effect on Postural Stability and Isokinetic Strength

To investigate which warm-up method is more effective on the postural stability and isokinetic strength, we conducted this study. Forty-five participants were recruited, all participants divided into three groups. Active warm-up consisted 12-minute jog on self-regulated treadmill followed by five push-ups, pull-ups, five-meter single leg hop to and from with alternate leg, five half and full squats, Passive warm-up consisted moist heat heating device, Combined warm-up involved active warm-up and passive warm-up exercises. The dynamic stability was tested by stabilometer. Test was done with open and closed eyes, with two stability level i.e. hard & easy. The isokinetic dynamometer was used to measure muscle performance. The test was done with 3 repetitions of concentric/concentric at low speed of 60/600/sec, followed by high speed of 180/1800/sec. Data were analyzed and findings revealed that combined warm-up is effective as active and passive warm-up for postural stability and isokinetic strength with significance differences.

Highly stretchable and durable strain sensor based on carbon nanotubes decorated thermoplastic polyurethane fibrous network with aligned wave-like structure

Recently, flexible strain sensors with large stretchability, high sensitivity and excellent stability have been widely concerned owing to their potential applications in wearable electronic devices. However, the challenge of narrow sensing range still remains for strain sensors with high performance. In this paper, we proposed a facile, cost-effective and scalable technology to manufacture the carbon nanotubes (CNTs)/thermoplastic polyurethane (TPU) fibrous strain sensor with aligned wave-like structure. Through electrospinning technique, we prepared an aligned TPU fibrous mat, then used a simple and effective assembly approach to induce CNTs to wrap TPU fibrous mat through ultrasonication. The sensing properties of CNTs/TPU mats in vertical and parallel directions were investigated, respectively. The sensing behaviors of the two sensors both agreed well with the tunneling theory. Compared with the random CNTs/TPU mats and parallel direction sample, the aligned CNTs/TPU fibrous mats in vertical direction possessed an ultra-high stretchability (900%) and excellent durability (10,000 cycles at the strain of 200%). An ultra-low detection limit (0.5%) and fast response time of 70 ms were also achieved, exhibiting a favorable sensitivity. The generation of the wave-like structure and the joints structure in the designed conductive network, which could affect the evolution of the conductive paths subsequently, led to these excellent sensing performances. The CNTs/TPU mats strain sensor was then assembled to monitor both subtle human motions, like cheek bulging and phonation; and vigorous human motions, like leg squatting and elbow bending, both showing excellent sensing performances. The present paper provides a good candidate for potential applications as artificial skins, human-activity monitoring and personal healthcare.

Training Unloading During Winter Break Improves Fitness in Male Rugby Players

When athletes experience training distress, a break in training may facilitate recovery and improve performance. Conversely, when team training is interrupted, such as occurs during winter break in collegiate athletes, deconditioning may result. In the current study, physiological responses to exercise were made before and after an unstructured winter break in male collegiate rugby players. PURPOSE: The purpose of the study was to examine detraining effects that occurred when structured training was interrupted for four weeks. METHODS: Fourteen (n=14) male club rugby players underwent exercise testing to assess aerobic capacity (VO2 max), strength (maximal bench press and leg squat), speed (10 yd dash), power (vertical jump), and body composition (body weight and % body fat by underwater weighing). A subject orientation of the testing was performed for all tests, and the treatment data were collected just prior to, and after the winter school break. T-tests were performed on pre- and post-winter break values. RESULTS: There was no evidence of detraining after four weeks of unstructured training. No changes were observed in bench press strength (183 versus 188.6 lbs) or speed (1.69 versus 1.69 seconds) across the break. However, performance measures for aerobic capacity (45.45 versus 47.70 ml/kg/min), squat strength (269.6 versus 308.2 lbs) and vertical jump (22.52 versus 23.94 inches) all showed significant improvements following the break. Additionally, there were significant increases in body weight (176.96 versus 178.63 lbs) and percent fat (12.76 versus 15.27% fat). CONCLUSION: Four weeks of unstructured training over the winter school break appears to have provided a recovery period that allowed for increases in physiological function despite increases in body fat.

Relationship Between Hip Muscle Activation and Frontal Plane Knee Motion During a Single - Leg Squat.

Relationship Between Hip Muscle Activation and Frontal Plane Knee Motion During a Single - Leg Squat.

Improving Strength and Power in Trained Athletes With 3 Weeks of Occlusion Training

To examine the effects of moderate-load exercise with and without blood-flow restriction (BFR) on strength, power, and repeated-sprint ability, along with acute and chronic salivary hormonal parameters. Twenty male semiprofessional rugby union athletes were randomized to a lower-body BFR intervention (an occlusion cuff inflated to 180 mmHg worn intermittently on the proximal thighs) or a control intervention that trained without occlusion in a crossover design. Experimental sessions were performed 3 times a week for 3 wk with 5 sets of 5 repetitions of bench press, leg squat, and pull-ups performed at 70% of 1-repetition maximum. Greater improvements were observed (occlusion training vs control) in bench press (5.4 ± 2.6 vs 3.3 ± 1.4 kg), squat (7.8 ± 2.1 vs 4.3 ± 1.4 kg), maximum sprint time (-0.03 ± 0.03 vs -0.01 ± 0.02 s), and leg power (168 ± 105 vs 68 ± 50 W). Greater exercise-induced salivary testosterone (ES 0.84-0.61) and cortisol responses (ES 0.65-0.20) were observed after the occlusion intervention sessions compared with the nonoccluded controls; however, the acute cortisol increases were attenuated across the training block. Occlusion training can potentially improve the rate of strength-training gains and fatigue resistance in trained athletes, possibly allowing greater gains from lower loading that could be of benefit during high training loads, in competitive seasons, or in a rehabilitative setting. The clear improvement in bench-press strength resulting from lower-body occlusion suggests a systemic effect of BFR training.

A new approach to measure functional stability of the knee based on changes in knee axis orientation

There is a lack of measures that quantify functional knee stability, which is of particular relevance in knee rehabilitation. Therefore, the aim of this study was to investigate the usefulness of knee finite helical axis (FHA) variables in 33 healthy subjects during two different functional tasks; One leg side hop (SH) and Two Leg Squat (TLS), and to investigate correlations of these variables with laxity. Laxity was assessed with a KT-1000 arthrometer and the Beighton Hypermobility Score. Movements were registered with an optical motion capture system. Knee rotation and translation were defined by a six degree of freedom segment model. FHA was calculated for finite steps of 20° knee flexion, based on error simulations. We computed the FHA inclination, the translation along FHA and an FHA Direction Index quantifying directional changes. All variables were repeatable (average ICCs ∼0.97 during TLS and ∼0.83 during SH). The lower functional knee stability in SH was reflected by a significantly higher FHA Direction Index and a larger medio-lateral FHA inclination compared to those in TLS. The superior–inferior inclination was smaller during Landing in SH compared to Take-Off and TLS. Translation along FHA was generally small as expected in healthy subjects. Beighton Hypermobility Score and KT-1000 values had weak but significant correlations with FHA Direction Index and FHA translation, which show that laxity influences the functional knee stability. We conclude that FHA measures were sensitive enough to discriminate between SH and TLS. The next step is to investigate the usability of these measures in subjects with knee injury.

Corticomotor plasticity following unilateral strength training

We used transcranial magnetic stimulation (TMS) to investigate 3 weeks of unilateral leg strength training on ipsilateral motor cortex (iM1) excitability, and short-latency intracortical inhibition (SICI). Right leg dominant participants (n = 14) were randomly divided into either a strength training (ST) or control group. The ST group completed 9 training sessions (4 sets of 6 to 8 repetitions of single right leg squats). We observed a 41% increase in right leg strength, and a 35% increase in strength of the untrained left leg (P < 0.01). There was a significant increase in motor evoked potential (MEP) amplitude recruitment curve for the untrained left leg (P < 0.01). SICI of the iM1 decreased by 21% for the untrained left leg (P < 0.01). The findings provide evidence for corticomotor adaptation for unilateral leg strength training within the iM1 that is modulated by changes in interhemispheric inhibition.

Intra-rater Reliability Of A Web-based, Dynamic Assessment Tool

(M.A. King. National Academy of Sports Medicine Consultant or Paid Advisor.) The Body Maptm is a web based transitional movement assessment tool used to detect muscle imbalances and generate custom exercise programs. Digital photos are taken at end range of motion (ROM) during double (DL) and single (SL) leg squats. A variety of judgments are made concerning the assessment of musculoskeletal deviations observed in the images. Corrective exercises are assigned based on movement observations addressing both rehabilitative and preventative interventions. An important aspect of a movement observation system that involves judgments, particularly with clinical application, is its within and between observer reliability. The present research focused on within rater reliability. PURPOSE The purpose of this study was to determine the assessment reliability of a novice user of the Body Map, trained using the instructional CD. METHODS Twenty subjects (11 females; 9 males; mean age, ht and wt of 34 ± 8 yrs, 169.5 ± 10.8 cm, 72.3 ± 12.8 kg) under went the Body Map assessment, consisting of images taken at the end ROM (max. knee flexion) during DL and SL squat tasks. During the DL, separate images were taken from the front, back and side views. During the SL squat, images were taken from the front view as subjects performed on both the right and left leg. All images were taken by an expert to eliminate possible confounding affect of testing protocol errors. After undergoing the instructional training as presented through the training CD, the novice rater assessed all subjects' images on two separate occasions. A total 26 possible asymmetries can be assessed from the images captured during the DL and SL squat tasks. Intra-rater reliability of each item was assessed by calculating the percent agreement and kappa coefficient for each item between the two assessment sessions. RESULTS Percent agreement ranged from 70–100% with a mean value of 89.8% ± 9.2% for all possible items scored on the Body Map. The Kappa coefficients ranged from moderate to excellent with over half (65%) in the good to excellent range. The overall mean score for the twenty six possible selections was 0.683 ± 0.246 (excellent 1.00 – 0.80; good 0.79 – 0.60; moderate 0.59 – 0.40; poor 0.39 – 0.20; very poor 0.19 – 0). CONCLUSIONS Use of the instructional CD that accompanies the Body Map Starter Kit adequately trains a novice rater to consistently and reliably assess transitional movement asymmetries based on the Body Map system. Although the within examiner ratings were quite high, some target areas were observed that are likely to be improved with more attention to introductory training materials. This is likely to increase the reliability of what appears to be a robust and potentially relevant clinical tool.

Assessment Of Physical Activity And Health-related Fitness For Physically Active People

PURPOSE To understand the health and musculoskeletal functions between ages 30 and 65 years, to investigate the relationship among the levels of fitness, to evaluate the health-related physical fitness test according to Urho Kaleva Kekkonen (UKK) Institute. METHODS The study sample selected from residents (103 women and 97 men mean age: 48,2±9,2) of the city of Ankara. Subjects were tested in five age (I. Group: 30–40 yrs, II. Group: 41–45yrs, III. Group: 46–50yrs, IV. Group: 51–55yrs and V. Group: 56+ yrs) cohorts. Before the tests, body composition evaluated with Body Mass Index (BMI) (mean: 25,4±3,2kg/m2), waist/hip ratio (mean: 0.85±0.1), skinfold measurements (mean: 29.4±6.5). All tests followed by a standart sequence; balance measured with one-leg standing, flexibility by trunk side-bending and knee extension range of motion by goniometric measurement, leg muscular power by jump and reach test; leg strength by one-leg squat, upper-body strength by modified push-ups and trunk muscular endurance test by static back extension. For cardiorespiratory endurance test assessed with the UKK 2km walk test after 10 minutes rest. RESULTS There were statistically differences in percent body fat, BMI, and knee extension range of motion in the ages of Group 1 between age groups (p<0.05). There were no statistically differences between age groups in the one-leg squat, modified push-ups, balance and cardiorespiratory endurance parameters (p>0.05). There were statistically differences in the one leg squat, trunk side-bending, cardiorespiratory endurance parameters between females and males (p<0.05). There were found statistically differences waist measurement, and fat percent between in females and males (p<0,05). CONCLUSIONS In this study the physical fitness levels were found an average and below the average between ages 30 and 65 in healthy subjects. Flexibility and cardiorespiratory endurance values of females and males parameters were found in the below of average.

Postexercise oxygen consumption and substrate use after resistance exercise in women.

This study investigated the acute effects of 45 min of resistance exercise (RE) on excess postexercise oxygen consumption (EPOC) and substrate oxidation 120 min after exercise in moderately trained women. Ten RE trained women (age = 29 +/- 3 yr; ht = 168 +/- 8.3 cm; wt = 59 +/- 5.7 kg; VO2max = 38.3 +/- 4.7 mL.kg-1.min-1) underwent two trials: control sitting and RE. Subjects acted as their own controls in a random counterbalanced design. A 2-d nonexercise period was established between testing trials. Oxygen consumption (VO2) and respiratory exchange ratio (RER) were measured continuously by indirect calorimetry before, during, and after exercise and on a separate control day. RE consisted of 3 sets of 10 exercises at 10-repetition maximum with a 1-min rest period between each set. Fingertip samples of blood lactate concentration [BL] were collected immediately postexercise and every 30 min thereafter until [BL] returned to resting baseline values after exercise. The overall 2-h EPOC was 6.2-L (RE = 33.4 +/- 5.1 L vs control = 27.2 +/- 0.3 L), corresponding to an 18.6% elevation over the control period. RER was significantly (P < 0.01) below the control RER from minute 30 to minute 120 postexercise (RE = 0.75 +/- 0.01 vs control = 0.85 +/- 0.01). During the last 30 min of recovery, VO2 and [BL] had returned to control/baseline values and fat oxidation was significantly (P < 0.0001) higher (29.2 vs 16.3 kcal) after RE compared with the control trial. These data indicate that in young RE trained women, acute RE produces a modest increase in VO2 during a 2-h recovery period and an increase in fat oxidation.

INFLUENCE OF CREATINE TYPE AND DIET ON STRENGTH AND BODY COMPOSITION OF COLLEGIATE LIGHTWEIGHT FOOTBALL PLAYERS

1505 Creatine powder (CP) has traditionally been used for creatine monohydrate supplementation (CMS). Creatine gum (CG) has recently been introduced. This study examined the influence of CMS type (CP & CG) on total strength (TS), body mass (BM), and sum of skinfolds (SS) of 31 collegiate lightweight football players (165 lb. competition) during a competitive season. Subjects completed BM, SS, and 1-RM testing (power clean, leg squat, bench press) 28 days apart during the football season, which included strength training 2 days/week. TS was the sum of the three lifts. Following the pre-test, subjects were matched via TS and randomly assigned to a CMS group. Both groups received identical doses of creatine {15 grams in 3-day period, CP; n=18 or CG; n=13} with 90% compliance. Subjects ate ad-libitium and all consumed food was monitored and analyzed by a RD utilizing nutritional software and food menus which denoted kilocalorie (KCAL) and protein intake (PI) based on the athlete's body mass. All meals were prepared by the school cafeteria. TS and BM increased and SS decreased (p<.01) in both groups. Two-way ANOVA (CP vs. CG) indicated no significant difference related to TS (p =.99), BM (p =.75), SS (p =.45), KCAL (3334,3418;±657, p =.73), and PI (1.9, 2.0;±.4, p =.50). It has been suggested that both KCAL and PI influence the ergogenic effect of CMS. Post-hoc analyses determined adequate KCAL intake(50 kcals/kg BM) along with PI (grams PI/kg BM). Subjects were classified regarding KCAL {Adequate, 4079 kcals (n = 10); Not Adequate, 3051 kcals (n = 21)} and PI (High Athlete,≥1.8g/kg, (n = 20, mean = 2.2g/kg); Low Athlete<1.8g/kg, (n = 11, mean = 1.5 g/kg)}. Additional analyses revealed no significant difference with any of the three dependent variables. In conclusion, for collegiate lightweight football players during a 28-day competitive season, there was no difference between CP and CG concerning TS, BM, and SS. Further, KCAL & PI did not appear to influence CMS, TS, BM, and SS.

The effect of dynamic constant external resistance training on the isokinetic torque-velocity curve.

The purpose of this investigation was to examine the effects of dynamic constant external resistance (DCER) training on isokinetic peak torque (PT) and constant joint angle (CJA) torque at velocities from zero to 5.03 rad.s-1. Twelve male volunteers (mean age +/- SD = 21.67 +/- 2.61 years) were trained using DCER exercises (leg extension and squat) for eight weeks. The subjects were tested pre-training and post-training for isokinetic leg extension PT as well as CJA torque (0.26 rad below the horizontal plane) at multiple velocities (zero, 0.84, 1.68, 2.51, 3.35, 4.19 and 5.03 rad.s-1) using a Cybex II isokinetic dynamometer. Film analyses indicated that the mean training velocities for leg extension and squat were 1.50 +/- 0.20 rad.s-1 and 1.41 +/- 0.26 rad.s-1, respectively. Univariate two-way repeated measures (within subjects design) ANOVAs [time (pre-training versus posttraining) x velocity] were used to analyze the changes in PT and CJA torque across the training period. There was no interaction but a significant (p < 0.05) main effect for time for the CJA torque measures. The increases in CJA torque ranged from 6.3 to 10.7%. For PT, there was a significant (p < 0.05) time x velocity interaction. Post-hoc comparisons showed that PT increased significantly at all velocities (p < 0.0083) as a result of the training (8.1 to 10.9%). The results of this investigation indicated that DCER training significantly increased isokinetic PT and CJA torque values at velocities up to 3.53 rad.s-1 above the training velocity.