Date: Wed, 16 Feb 2000 21:19:59 -0600 From: "Thomas Incledon" Subject: Re: bench weak points - long with citations I read through through various papers on bench press technique and electrymyographic readings. As we would guess there are distinct differences between novice and expert bench pressers (expert in this context represents 9 powerlifters - 3 each 242s, 275s, SHs from the 1978, 1979, 1980 senior nationals and/or world championships). Experts bench pressers tend to: - - lower the bar more slowly - - raise the bar faster - - shoulder torque is much greater than one would predict for heavy expert benchers (in one of the weight classes above). This means that shoulder torque increases faster than increasing the weight of the bar. This may be explained by the fact that the competition grip width is limited on an absolute basis, so larger guys are given the same space to grip that smaller guys are. It appears in an ideal world the grip space would be set on a relative basis. - - the larger lifters above positioned the bar further from their bodies relative to their body size than smaller lifters from a previous study. This again may be related to the grip width issue. The options are to increase elbow flexion and bring in more tricpes or displace the bar more horizontally. The lifters above chose the second option. - - in terms of bench press skill, the two studies I reviewed indicate that lghter lifters may be more proficient - - just to make it clear, there were no bench shirts on these guys. This can certainly have an impact as well I pasted in a variety of studies that address different issues regarding the bench press. the biomechanical studies are towards the end of the citations. I believe only two studies using a total of 30 or so lifters have studies the biomechanics of bench pressing. This seems to leave lots of opportunities to study this area in far more detail then what is presently known. later, Tom Something else occurred to me after I sent the last post on this topic. In that post, comparisons were made for the bench press techniques between heavy expert and novice and another study on light expert lifters was also used for comparison. In these studies the authors were reporting what they observed (ie the bar moved this way and then the bar moved that way). They should have included a section where they asked the lifters what they were trying to do with the bar (ie push it straight up). Then a comparison could have been made between the intent and the actual result. This would provide some interesting research as well as training information. Let's assume I want to push the bar straight up. I could video tape my benches, follow the bar path from my video. If I observe a movement pattern that is not what I want (ie the bar moves towards my head too early) perhaps then a training strategy can be developed to target the necessary muscles combined with training with lighter loads to emphasize technique. This is done in weight lifting all the time. We would video tape our lifts and then after each set go back and review the video so that we could try to improve upon what was done. It's delayed feedback but he certainly helps to see technical flaws and (hopefully) correct them. Thomas Incledon, MS, RD, LD, LN, CSCS, NSCA-CPT Director of Sports Nutrition Human Performance Specialists, Inc. 619 NW 90th Terrace Plantation, FL 33324 954-577-0689 hpsinc@mediaone.net Citation 1 Unique Identifier 99451271 Authors Izquierdo M. Ibanez J. Gorostiaga E. Garrues M. Zuniga A. Anton A. Larrion JL. Hakkinen K. Institution Centro de Investigacion y Medicina del Deporte. Gobierno de Navarra, Navarra, Spain. Title Maximal strength and power characteristics in isometric and dynamic actions of the upper and lower extremities in middle-aged and older men. Source Acta Physiologica Scandinavica. 167(1):57-68, 1999 Sep. Abstract Muscle cross-sectional area of the quadriceps femoris (CSAQF), maximal isometric strength (handgrip test and unilateral knee extension/flexion), the shape of isometric force-time curves, and power-load curves during concentric and stretch-shortening cycle (SSC) actions with loads ranging from 15 to 70% of one repetition maximum half-squat (1RMHS) and bench-press (1RMBP) were examined in 26 middle-aged men in the 40-year-old (M40) (mean age 42, range 35-46) and 21 elderly men in the 65-year-old age group (M65) (mean age 65, range 60-74). Maximal bilateral concentric (1RMHS and 1RMBP), unilateral knee extension (isometric; MIFKE and concentric; 1RMKE) strength and muscle CSA in M65 were lower (P < 0.001) than in M40. The individual values of the CSAQF correlated with the individual values of maximal concentric 1RMHS, 1RMKE and MIFKE in M65, while the corresponding correlations were lower in M40. The maximal MIFKE value per CSA of 4.54 +/- 0.7 N m cm-2 in M40 was greater (P < 0. 05-0.01) than that of 4.02 +/- 0.7 N m cm-2 recorded in M65. The maximal rate of force development of the knee extensors and flexors in M65 was lower (P < 0.01-0.001) and the heights in squat and counter-movement jumps as much as 27-29% lower (P < 0.001) than those recorded in M40. M65 showed lower (P < 0.001) concentric power values for both upper and lower extremity performances than those recorded for M40. Maximal power output was maximized at the 30-45% loads for the upper extremity and at the 60-70% loads for the lower extremity extensors in both age groups. Muscle activation of the antagonists was significantly higher (P < 0.01-0.001) during the isometric and dynamic knee extension actions in M65 than in M40. The present results support a general concept that parallel declines in muscle mass and maximal strength take place with increasing age, although loss of strength may vary in both lower and upper extremity muscles in relation to the type of action and that ageing may also lead to a decrease in voluntary neural drive to the muscles. Explosive strength and power seem to decrease with increasing age even more than maximal isometric strength in both actions but power was maximized at the 30-45% loads for the upper and at the 60-70% loads for the lower extremity action in both age groups. High antagonist muscle activity may limit the full movement efficiency depending on the type of muscle action, testing conditions and the velocity and/or the time duration of the action, especially in the elderly. - ---------------------------------------------------------------------------- - ---- Citation 2 Unique Identifier 97279991 Authors Newton RU. Murphy AJ. Humphries BJ. Wilson GJ. Kraemer WJ. Hakkinen K. Institution Centre for Exercise Science and Sport Management, Southern Cross University, Lismore, NSW, Australia. Title Influence of load and stretch shortening cycle on the kinematics, kinetics and muscle activation that occurs during explosive upper-body movements. Source European Journal of Applied Physiology & Occupational Physiology. 75(4):333-42, 1997. Abstract Although explosive power in lower-body movements has been extensively studied, there is a paucity of research examining such movements in the upper body. This study aimed to investigate the influence of load and the stretch shortening cycle (SSC) on the kinematics, kinetics, and muscle activation that occurs during maximal effort throws. A total of 17 male subjects performed SSC and concentric only (CO) bench throws using loads of 15%, 30%, 45%, 60%, 75%, 90% and 100% of their previously determined one repetition maximum bench press. The displacement, velocity, acceleration, force and power output as well as the electromyogram (EMG) from pectoralis major, anterior deltoid, and triceps brachii were recorded for each throw. The results were compared using multivariate analysis of variance with repeated measures. A criterion alpha level of P < or = 0.05 was used. Similar force velocity power relationships were determined for this multijoint upper-body movement as has been found for isolated muscles, single joint movements, and vertical jumping. The highest power output was produced at the 30% [563 (104) W] and 45% [560 (86) W] loads during the SSC throws. Force output increased as a function of load; however, even the lighter loads resulted in considerable force due to the high accelerations produced. Average velocity, average and peak force, and average and peak power output were significantly higher for the SSC throws compared to the CO throws. However, peak velocity and height thrown were not potentiated by performing the pre-stretch because the duration and range of movement allowed the ability of the muscle to generate force at high shortening velocities to dominate the resulting throw. As such, explosive movements involving longer concentric actions than experienced during brief SSC movements may be limited by the ability of the muscle to produce force during fast contraction velocities. - ---------------------------------------------------------------------------- - ---- Citation 3 Unique Identifier 97168885 Authors Wilson GJ. Murphy AJ. Walshe AD. Ness K. Institution Centre for Exercise Science and Sport Management, Southern Cross University, Australia. Title Stretch shorten cycle performance: detrimental effects of not equating the natural and movement frequencies. Source Research Quarterly for Exercise & Sport. 67(4):373-9, 1996 Dec. Abstract This study aimed to assess whether the benefits associated with stretch shorten cycle (SSC) movements required the movement frequency to be in resonance with the natural frequency of the elastic structures. Seventeen untrained participants performed SSC and concentric bench press throws. Further, quasi-static muscular actions were also performed in which a brief perturbation was applied to the bar with the resulting damped oscillations providing natural frequency data. It was observed that prior stretch did not facilitate concentric performance. Further, there were large significant differences between the natural frequency of the musculo-tendinous system and the frequency of the SSC movements. The authors hypothesize that the failure to achieve resonance contributed to the poor performance achieved in the SSC actions. - ---------------------------------------------------------------------------- - ---- Citation 4 Unique Identifier 97006177 Authors Wilson GJ. Murphy AJ. Giorgi A. Institution Centre for Exercise Science & Sport Management, Southern Cross University, Lismore NSW, Australia. Title Weight and plyometric training: effects on eccentric and concentric force production. Source Canadian Journal of Applied Physiology. 21(4):301-15, 1996 Aug. Abstract The study was performed in an effort to gain greater insights into the adaptations invoked by plyometric and weight training. Forty-one previously trained males were randomly allocated in either a control, plyometric, or weight-training group. The experimental groups trained for 8 weeks, performing either heavy lifts or dynamic plyometric exercises. The following test items were performed prior to and at the completion of the training period: (a) vertical jump, (b) a series of isoinertial concentric and eccentric tests, (c) push-up tests, and (d) maximal bench press and squat lifts. Plyometric training significantly enhanced the rate of eccentric lower body force production. The weight-training group primarily enhanced concentric function. These results were attributed to the specific stresses imposed by the differing forms of training and are discussed with reference to methods of enhancing training induced adaptations and the types of movements such training would tend to facilitate. - ---------------------------------------------------------------------------- - ---- Citation 5 Unique Identifier 96375557 Authors Murphy AJ. Wilson GJ. Institution Centre for Exercise Science and Sport Management, Southern Cross University, Lismore, NSW, Australia. Title Poor correlations between isometric tests and dynamic performance: relationship to muscle activation. Source European Journal of Applied Physiology & Occupational Physiology. 73(3-4):353-7, 1996. Abstract The purpose of this research was to perform isometric tests at two joint angles and examine their relationship to dynamic performance. In addition, electromyograph data were collected from the triceps brachii and pectoralis major muscles to compare underlying neural characteristics between the isometric tests and dynamic movement. A group of 24 healthy male subjects performed two isometric tests in a bench press position, at elbow angles of 90 and 120 degrees. From these data, the maximal force and rate of force development were determined. In addition, each subject performed a seated medicine ball throw as a measure of dynamic upper body performance. Correlations showed that isometric measurements of force (r = 0.47-0.55) and rate of force development (r = 0.08-0.31) were poor predictors of dynamic performance. The angle of isometric assessment had little effect on the relationship between the tests and measurements of performance. The myo-electric data was processed in terms of the integrated electromyogram and the Fourier transformed frequency spectrum. These data demonstrated differences in the neural activation patterns of the musculature, between the isometric 90 degrees test and the medicine ball throw. The poor relationship between isometric tests and medicine ball performance was consequently, at least partially, attributed to differing motor unit activation patterns between isometric and dynamic movement. The results of this research strongly suggest that isometric tests have limited value when assessing dynamic upper body performance. - ---------------------------------------------------------------------------- - ---- Citation 6 Unique Identifier 96375556 Authors Wilson GJ. Murphy AJ. Walshe A. Institution Centre for Exercise Science and Sport Management, Southern Cross University, Lismore, NSW, Australia. Title The specificity of strength training: the effect of posture. Source European Journal of Applied Physiology & Occupational Physiology. 73(3-4):346-52, 1996. Abstract There is a paucity of research into the importance of performing strength training exercises in postures specific to the movements they are attempting to facilitate. In addressing this question, 27 previously trained subjects were randomly allocated into heavy weight training and control groups. The weight training group performed 4-6 sets of 6-10 repetitions of the squat and bench press lifts twice a week for 8 weeks. Prior to and after the training period the following tests were conducted: bench press throw at 30% of maximal load, vertical jump, maximal squat and bench press lifts, push-up test performed over a force platform, 40-m sprint, 6-s cycle, and isokinetic tests assessing upper and lower body musculature in varying actions. The results supported the concept that posture is important in training as those exercises conducted in similar postures to the training recorded the greatest improvement in performance. For example, after completion of the training the weight training subjects significantly increased by approximately 12% the maximal load lifted in the bench press exercise and the peak torque in the isokinetic bench press test. However, performance in the isokinetic horizontal arm adduction test was not significantly changed. We speculate that the phenomenon of posture specificity may, at least in part, be caused by the differing postures altering the neural input to the musculature. The results stress the importance of selecting exercises in which the posture closely resembles that of the movements they are attempting to facilitate. - ---------------------------------------------------------------------------- - ---- Citation 7 Unique Identifier 96102522 Authors Mayhew JL. Prinster JL. Ware JS. Zimmer DL. Arabas JR. Bemben MG. Institution Human Performance Laboratory, Northeast Missouri State University, Kirksville 63501, USA. Title Muscular endurance repetitions to predict bench press strength in men of different training levels. Source Journal of Sports Medicine & Physical Fitness. 35(2):108-13, 1995 Jun. Abstract The purpose of this study was to determine the accuracy of predicting maximal bench press (BP) strength (1-RM) from relative endurance performance in various groups of men. The subjects included untrained students (n = 35), resistance trained students (n = 28), college wrestlers (n = 21), soccer players (n = 22), football players (n = 51), high school students (n = 35), and resistance-trained middle-aged men (n = 24). Each subject performed a 1-RM test according to the same standard procedure. Within 4-10 days, the subject selected a weight to perform as many repetitions as possible to failure. Six relative endurance prediction equations produced validity coefficients of r = 0.86 to 0.98 in each group and r = 0.82 to 0.98 in the composite group (n = 220). In subjects completing < or = 10 repetitions-to-failure, three equations significantly overpredicted and two significantly underpredicted 1-RM scores. The Brzycki equation was the most accurate. In subjects completing > 10 repetitions to failure, three equations significantly overpredicted and three significantly underpredicted 1-RM scores. While caution should be used when employing relative muscular endurance performance to estimate 1-RM strength in the bench press, the average of two equations may reduce the error. - ---------------------------------------------------------------------------- - ---- Citation 8 Unique Identifier 95371322 Authors Bale P. Colley E. Mayhew JL. Piper FC. Ware JS. Institution Human Performance Laboratory, Brighton University, Eastbourne, UK. Title Anthropometric and somatotype variables related to strength in American football players. Source Journal of Sports Medicine & Physical Fitness. 34(4):383-9, 1994 Dec. Abstract The purpose of this study was to investigate the differences in somatotype, % fat, and strength in relation to body mass of two groups of American football players. One hundred and forty-three football players (85 high school and 58 college) were classified into five weight groups (< 73 kg, 73-82 kg, 83-91 kg, 91-100 kg, > 100 kg). Body composition was estimated from skinfold, and somatotype was determined using the Heath-Carter method. Strength was measured from one-repetition maximum (1-RM) lifts in the bench press and deadlift. Most of the somatotypes were dominant mesomorphs for the high school player and endomesomorphs for the college player. The weight groups in both the high school and college footballer showed significant differences in % fat, somatotype, and strength measures between the lower and higher weight categories. Weight was a greater factor dictating strength in either lift in the high school player than in the college player. A higher mesomorphic component was a more important factor determining strength in the college player while a lower ectomorphic component contributed more in the high school player. The proportion of the variance accounted for by regression equations for the bench press and deadlift was 17% to 41% in the high school player and 35% to 61% in the college player. Although football requires a large individual at certain positions, the question remains concerning overall size versus muscularity to achieve a superior performance level. - ---------------------------------------------------------------------------- - ---- Citation 9 Unique Identifier 95160203 Authors Williford HN. Kirkpatrick J. Scharff-Olson M. Blessing DL. Wang NZ. Institution Department of Physical Education, Auburn University at Montgomery, Alabama 36117. Title Physical and performance characteristics of successful high school football players. Source American Journal of Sports Medicine. 22(6):859-62, 1994 Nov-Dec. Abstract The purpose of this investigation was to determine the performance and physiologic characteristics of a "successful" American high school football team, and to compare the present values with values reported for other groups of high school, college, and professional players. For descriptive purposes, players were divided into two groups: backs (N = 8) and linemen (N = 10). Maximal aerobic power (VO2max) was determined from a maximal treadmill test, and body composition was evaluated by hydrostatic weighing. Maximal strength values were evaluated by one-repetition maximum bench press and squat test; the sit-and-reach test was used to measure flexibility. Speed and power were evaluated by a vertical jump and a 36.6-meter sprint. Results indicate that compared with other groups of college and professional players, as the level of competition increases so do height, weight, and fat-free weight of the players. Similar maximum oxygen consumption values were found for the present group when compared with other groups of these players. From the strength and power standpoint, football players at all levels are becoming stronger. Incorporation of strength training programs has greatly improved strength and performance profiles of football players at all levels of competition. - ---------------------------------------------------------------------------- - ---- Citation 10 Unique Identifier 95094777 Authors Murphy AJ. Wilson GJ. Pryor JF. Institution Centre for Exercise Science and Sport Management, Southern Cross University, Lismore, NSW, Australia. Title Use of the iso-inertial force mass relationship in the prediction of dynamic human performance. Source European Journal of Applied Physiology & Occupational Physiology. 69(3):250-7, 1994. Abstract The purpose of this investigation was to develop a new test of muscle function, termed the iso-inertial force-mass relationship, and to determine its relationship to dynamic physical performance in comparison to an isometric test. A group of 13 trained subjects performed an isometric, and a series of iso-inertial maximal upper body tests, in a bench press movement at loads of 30%, 60%, 100% (concentric) and 100%, 130% and 150% (eccentric) of maximum. Vertical forces exerted throughout the movement were recorded by a force plate. In addition, the subjects performed the following three performance tests: a maximal bench press, a seated shotput, and two drop bench-press throws from a height of 0.25 m, with loads of 10 kg and 30% of maximum. Correlation analysis demonstrated that in each instance the iso-inertial force mass tests were the best predictors of performance (r = 0.78-0.88) with both contraction type and mass specific effects apparent. Maximal isometric force and rate of force development were significantly related to some performance variables (r = 0.22-0.78). However, for all the performance movements assessed, the iso-inertial test modality recorded the highest relationship to performance. The difference in the relationship between performance and iso-inertial and isometric test modalities was particularly evident in the light load dynamic performance of the seated shotput (r = 0.86 vs r = 0.38, respectively). These results are explained in part by the neural and mechanical differences between iso-inertial and isometric muscle actions and their respective specificity to dynamic physical performance. - ---------------------------------------------------------------------------- - ---- Citation 11 Unique Identifier 95013943 Authors Wilson GJ. Murphy AJ. Pryor JF. Institution Centre for Human Movement Science and Sport Management, Southern Cross University, Lismore, New South Wales, Australia. Title Musculotendinous stiffness: its relationship to eccentric, isometric, and concentric performance. Source Journal of Applied Physiology. 76(6):2714-9, 1994 Jun. Abstract The purpose of this study was to quantify the relationship between musculotendinous stiffness and performance in eccentric, isometric, and concentric activities. Thirteen trained subjects performed a series of maximal effort eccentric, concentric, and isometric muscular contractions in a bench press-type movement. Additionally, subjects performed a series of quasi-static muscular contractions in a bench press movement. A brief perturbation was applied to the bar while these isometric efforts were maintained, and the resulting damped oscillations provided data pertaining to each subject's musculotendinous stiffness. Musculotendinous stiffness was significantly related to isometric and concentric performance (r = 0.57-0.78) but not to eccentric performance. These results are interpreted as demonstrating that the optimal musculotendinous stiffness for maximum con centric and isometric activities was toward the stiff end of the elasticity continuum. A stiffer musculotendinous unit may facilitate such performances by improving the force production capabilities of the contractile component, due to a combination of improved length and rate of shortening, and additionally by enhancing initial force transmission. - ---------------------------------------------------------------------------- - ---- Citation 12 Unique Identifier 94017633 Authors Mayhew JL. Piper FC. Ware JS. Institution Human Performance Laboratory, Northeast Missouri State University, Kirksville. Title Anthropometric correlates with strength performance among resistance trained athletes. Source Journal of Sports Medicine & Physical Fitness. 33(2):159-65, 1993 Jun. Abstract The purpose of this study was to determine the relationship between selected anthropometric dimensions and strength performance in resistance trained athletes. Fifty-eight college football players were measured following the completion of a 10-week resistance training program for one-repetition maximum (1-RM) lifts in the bench press, squat, and dead lift and for 11 anthropometric dimensions. Results indicated that the highest relationships existed between estimates of regional muscle mass (arm circumference, arm muscle cross-sectional area, and thigh circumference) and lifting performance. Multiple regression analysis selected arm size and %fat as variables common to the prediction of all three lifts. The fewer joints and muscle groups involved in a lift, the greater the predictive accuracy from structural dimensions. It was concluded that body structure and conformation make significant contributions to maximum strength performance in highly trained strength athletes. - ---------------------------------------------------------------------------- - ---- Citation 13 Unique Identifier 92092664 Authors Mayhew JL. Ball TE. Ward TE. Hart CL. Arnold MD. Institution Human Performance Laboratory, Northeast Missouri State University, Kirksville. Title Relationships of structural dimensions to bench press strength in college males. Source Journal of Sports Medicine & Physical Fitness. 31(2):135-41, 1991 Jun. Abstract The purpose of this study was to determine the relationships between structural dimensions and bench press performance in college males. Members of required fitness classes (n = 170) were measured after 14 weeks of strength and aerobic endurance training. Anthropometric dimensions included upper arm and chest circumferences, upper and lower arm lengths, shoulder and hip widths, %fat, and height. Arm muscle cross-sectional area (CSA) was calculated from upper arm circumference corrected for triceps skinfold. Drop distance was measured from the bar to the pectoral muscles. Multiple regression analysis selected upper arm CSA, %fat, and chest circumference as the best items to predict bench press strength (R = 0.83; SEE = 11.6 kg). Cross-validation of the prediction equation on a similar sample (n = 89) produced an r = 0.74 between predicted and actual bench press (t = 0.53, p greater than 0.50). In a second cross validation sample (n = 57) who had trained more extensively with weights, the correlation between predicted and actual bench press was r = 0.57 (p less than 0.05). The prediction equations significantly (t = 6.59, p less than 0.01) underestimated bench press performance in the more extensively weight trained subjects. The results of this study suggest that bench press performance is related to structural dimensions in males and that extensive strength training may alter the relationship between size and strength. - ---------------------------------------------------------------------------- - ---- Citation 14 Unique Identifier 91246761 Authors Hortobagyi T. Katch FI. Institution Department of Sport Science/Biology, University of Denver, CO 80210. Title Reliability of muscle mechanical characteristics for isokinetic and isotonic squat and bench press exercise using a multifunction computerized dynamometer. Source Research Quarterly for Exercise & Sport. 61(2):191-5, 1990 Jun. Citation 15 Unique Identifier 91085970 Authors Hortobagyi T. Katch FI. Katch VL. LaChance PF. Behnke AR. Institution Department of Exercise Science, University of Massachusetts, Amherst 01003. Title Relationships of body size, segmental dimensions, and ponderal equivalents to muscular strength in high-strength and low-strength subjects. Source International Journal of Sports Medicine. 11(5):349-56, 1990 Oct. Abstract There are conflicting results in prior studies concerning the relationships among body size, muscle size, and muscular strength. The purpose of the present study was to evaluate how body size, body shape, and segmental dimensions related to individual differences in muscular strength. Subjects were tested on four dynamic measures of strength and then classified into one of two groups as high strength (HS; N = 21) and low strength (LS; N = 21). Individual differences in strength were then related to body composition and segmental anthropometry. Strength was assessed during high-resistance, low-velocity standing squat and supine bench press with an isokinetic dynamometer, and during seated bench press and knee extension with a hydraulic resistance dynamometer. Anthropometry and body composition included 11 girths, six fatfolds, predicted fat-free mass (FFM), thigh and upper arm volume, muscle + bone cross-sectional area (CSA), and the Behnke Ponderal Somatogram (PSom) body profiling system. There was a 21.3% difference in strength between HS and LS (p less than 0.05), but no significant differences in age, stature, and fatfolds. MANOVA revealed that seven of 11 girth components of PSom were larger for HS (p less than 0.05). The correlations between strength vs body mass, FFM, thigh and upper arm volume, and CSA and fatfolds in HS and LS ranged from r = -0.52 to 0.56 (r = -0.70 to 0.70 when corrected for restriction of range). We conclude that individual differences in muscular strength are poorly related to various measures of body size and segmental body dimensions. - ---------------------------------------------------------------------------- - ---- Citation 16 Unique Identifier 89384089 Authors Elliott BC. Wilson GJ. Kerr GK. Institution Department of Human Movement and Recreation Studies, University of Western Australia, Nedlands. Title A biomechanical analysis of the sticking region in the bench press. Source Medicine & Science in Sports & Exercise. 21(4):450-62, 1989 Aug. Abstract The performance of ten elite powerlifters were analyzed in a simulated competition environment using three-dimensional cinematography and surface electromyography while bench pressing approximately 80% of maximum, a maximal load, and an unsuccessful supramaximal attempt. The resultant moment arm (from the sagittal and transverse planes) of the weight about the shoulder axis decreased throughout the upward movement of the bar. The resultant moment arm of the weight about the elbow axis decreased throughout the initial portion of the ascent of the bar, recording a minimum value during the sticking region, and subsequently increased throughout the remainder of the ascent of the bar. The electromyograms produced by the prime mover muscles (sternal portion of pectoralis major, anterior deltoid, long head of triceps brachii) achieved maximal activation at the commencement of the ascent phase of the lift and maintained this level essentially unchanged throughout the upward movement of the bar. The sticking region, therefore, did not appear to be caused by an increase in the moment arm of the weight about the shoulder or elbow joints or by a minimization of muscular activity during this region. A possible mechanism which envisages the sticking region as a force-reduced transition phase between a strain energy-assisted acceleration phase and a mechanically advantageous maximum strength region is postulated. - ---------------------------------------------------------------------------- - ---- Citation 17 Unique Identifier 87190328 Authors Vandervoort AA. Sale DG. Moroz JR. Title Strength-velocity relationship and fatiguability of unilateral versus bilateral arm extension. Source European Journal of Applied Physiology & Occupational Physiology. 56(2):201-5, 1987. Abstract Strength-velocity relations and fatigue resistance in an arm bench press manoeuvre were compared between conditions of bilateral (BL, both arms acting together) and unilateral muscle contraction in 9 young men. BL and UL (sum of the 2 arms acting singly) strength was similar for isometric and slow isokinetic maximal voluntary contractions (MVC); at high velocities BL MVC declined more than UL. In both types of contractions a curvilinear relation was observed between strength and velocity, with significantly higher peak torques (PT) being produced under isometric conditions than for slow velocity efforts (p less than 0.01). Mean declines in PT during 100 repetitive MVCs of approximately 70s were to 25% of initial values for the BL fatigue test and to 37% for UL (p less than 0.01). In contrast to results of a similar investigation of leg extension in the same subjects, the arms showed no BL deficit of strength in the initial part of the strength-velocity curve and approximately twice as much fatigue in repetitive contractions. These physiological differences may stem from the varying habitual activity patterns of the arms and legs. - ---------------------------------------------------------------------------- - ---- Citation 18 Unique Identifier 85267148 Authors Lander JE. Bates BT. Sawhill JA. Hamill J. Title A comparison between free-weight and isokinetic bench pressing. Source Medicine & Science in Sports & Exercise. 17(3):344-53, 1985 Jun. Abstract The purpose of the study was to evaluate selected parameters describing performance characteristics of a free-weight and isokinetic bench press. A secondary purpose was an attempt to clarify the technique requirements essential for a successful lift. Parameters describing the free-weight condition were generated from cinematographic data (150 fps) for five trials each at 90 and 75% of the subject's maximal performance (1RM). Isokinetic data were obtained from an instrumented Cybex Power Bench Press at two speeds corresponding to the average speeds for the free-weight conditions. Despite differences, accommodation appeared to occur for both methods when the lifts were performed maximally. A "sticking region" was defined as the portion of the free-weight activity when the subjects' force application was less than the weight of the bar. No significant difference (P less than 0.05) was observed between the 90% 1RM (26.02%) and 75% 1RM (26.94%) mean relative time values for these regions. For the Cybex device, the percentage of the activity which was isokinetic was longer for the slower speeds of rotation (0.47 rad X s-1 = 70%) and steadily decreased until the movement was only 50% isokinetic at 1.74 rad X s-1. The observed relationships between applied force-time data along with anatomical considerations suggest an ideal technique for the lift. - ---------------------------------------------------------------------------- - ---- Citation 19 Unique Identifier 85035680 Authors Madsen N. McLaughlin T. Title Kinematic factors influencing performance and injury risk in the bench press exercise. Source Medicine & Science in Sports & Exercise. 16(4):376-81, 1984 Aug. Abstract The purpose of this research was to identify kinematic factors that could be relevant to performance and injury risk in the bench press. The methods used included: use of high-speed, 2D cinematographic procedures to record the performances of 36 subjects (19 experts and 17 novices), determination of the kinematic and kinetic differences between the groups, and identification of a rationale describing how those kinematic differences could lead to the kinetic differences. Kinematic factors so identified could influence performance and injury risk. In addition to the fact that experts were able to lift 79% more weight than the novices, the pertinent kinetic differences included the following: 1) the difference in peak force exerted while lowering the bar was only 43%; 2) the difference in peak force exerted while raising the bar was only 45%; and 3) the difference in minimum force exerted while raising the bar was 87%. There was no significant difference in torque required at the shoulder. The relevant kinematic differences were: 1) the expert group maintained a smaller bar speed while lowering the bar, 2) the expert group used a bar path closer to the shoulders; and 3) the expert group used a different sequence of bar movements. The roles of these kinematic factors in the bench press merit further investigation. - ---------------------------------------------------------------------------- - ---- Citation 20 Unique Identifier 76103976 Authors Rosentswieg J. Hinson M. Ridgway M. Title An electromyographic comparison of an isokinetic bench press performed at three speeds. Source Research Quarterly. 46(4):471-5, 1975 Dec.