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Objectives: To determine if force differences exist between isometric pulling positions corresponding to key positions of the deadlift. Design: Cross-sectional evaluation of isometric strength Methods: 14 powerlifters performed isometric pulls on a force plate at 3 key positions related to the deadlift (at the floor, just above the patella, and 5-6 cm short of lockout) and in the mid thigh pull position (MTP). A 1x4 repeated measures ANOVA was used to ascertain differences between the various pulling positions tested. Bonferroni-adjusted paired samples t-tests were used post-hoc. Results: Forces generated at each bar height were significantly different (F(3,39) = 51.058, p<0.05, η2=0.80). Paired samples t-tests showed significant differences between positions, revealing a trend of greater force generation at increasing heights for positions corresponding to the deadlift. Force generated in the mid thigh pull position was significantly higher than any other position. Conclusion: In positions corresponding to the deadlift, force generation increases at higher bar heights.
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owerlifting is a sport made up of three events, the squat,
bench press and deadlift. For each event, the ultimate goal
is to lift as much weight as is possible. In the deadlift, a lifter
lifts the barbell off of the floor until standing upright. The lift
is finished upon extending the knees and hips with scapula
retracted. Two styles of the deadlift are used in competition.
The sumo style uses a wide foot stance, upright posture, and a
grip width that is narrower than the feet.
Conversely, the
conventional style deadlift uses a narrow foot stance, generally
a more bent-over posture, and a grip outside of the legs.
Three key phases have been identified in the literature for
the conventional deadlift.
The first phase, or lift-off, occurs
when the lifter first applies force to the bar and the bar rises off
of the floor. The second phase, knee passing, occurs when the
bar moves from below to above the knee. The third phase, or
lift completion, occurs when the lifter transitions into a full
upright position. While these specific regions of the deadlift
are known, little has been done to examine how each position
might contribute to deadlift performance. The most
disadvantageous position represents a limiting factor in overall
performance, thus identification of this position may lead to
better training prescriptions.
To the authors’ knowledge, no literature exists that assesses
the force generation capabilities of lifters in these phases of the
deadlift, however in a number of studies examining the
isometric mid thigh pull (MTP), a weightlifting-specific
position, a variety of athletes produced high levels of peak
Peak force measured in these studies showed
moderate to strong relationships with dynamic mid-thigh pulls,
jumps and a number of other dynamic measures. Therefore,
since little is known about the force generation capabilities of
lifters in the key phases of the deadlift, the purpose of the
study was to evaluate the isometric maximum strength of
powerlifters in bar positions corresponding to key phases of
the deadlift and also to compare those positions to the MTP,
given the strong relationship the MTP shares with a variety of
dynamic measures.
Experimental Approach to the Problem
Data obtained in an athlete monitoring program were
assessed using a repeated measures design to assess peak force
production differences between key positions of the deadlift. A
repeated measures ANOVA and paired t-tests were used to
assess force differences between positions.
Fourteen competitive powerlifters who could deadlift a
minimum of 2.5 x body mass (BdM) using the conventional
style using only a belt or competed regularly volunteered for
this investigation. Based upon training history questionnaires
all subjects reported that they did not regularly perform
weightlifting movements or their variants. Some lifters
reported using the sumo style most often in competition (n=4),
Short Communication
Isometric Strength of Powerlifters in Key Positions
of the Conventional Deadlift
George K. Beckham, Hugh S. Lamont, Kimitake Sato, Michael W. Ramsey, G. Gregory Haff, Michael H. Stone
Objectives: To determine if force differences exist between isometric pulling positions corresponding to key positions of the
Design: Cross-sectional evaluation of isometric strength
Methods: 14 powerlifters performed isometric pulls on a force plate at 3 key positions related to the deadlift (at the floor,
just above the patella, and 5-6 cm short of lockout) and in the mid thigh pull position (MTP). A 1x4 repeated measures
ANOVA was used to ascertain differences between the various pulling positions tested. Bonferroni-adjusted paired
samples t-tests were used post-hoc.
Results: Forces generated at each bar height were significantly different (F(3,39) = 51.058, p<0.05, η
=0.80). Paired
samples t-tests showed significant differences between positions, revealing a trend of greater force generation at
increasing heights for positions corresponding to the deadlift. Force generated in the mid thigh pull position was
significantly higher than any other position.
Conclusion: In positions corresponding to the deadlift, force generation increases at higher bar heights.
(Journal of Trainology 2012;1:32-35)
Key words: powerlifting
strength testing
performance monitoring
maximum strength
isometric mid thigh pull
Received October 17, 2012; accepted November 12, 2012
From Center of Excellence for Sport Science and Coach Education, Department of Kinesiology, Leisure, and Sports Science, East Tennessee State
University, Johnson City, TN, USA (G.K.B., H.S.L., K.S., M.W.R., M.H.S), and Centre for Exercise and Sport Science Research, Edith Cowan University,
Perth, Australia (G.G.H., M.H.S).
Communicated by Takashi Abe, PhD
Correspondence to Mr. George K. Beckham, East Tennessee State University, PO Box 70654. Email:
Journal of Trainology 2012:1:32-35 ©2012 The Active Aging Research Center
Beckham et al. Isometric Strength of Powerlifters in Key Positions of the Conventional Deadlift 33
but all lifters reported training regularly using the conventional
style (n=14, age range: 18-39, height: 178.6±9.8cm, BdM:
109.9±20kg, conventional deadlift 1-RM: 248.5±18kg). Each
subject was screened by questionnaire for injury prior to
testing. Athletes were informed of all testing procedures and
possible risks, and voluntarily signed an informed consent
document as outlined by University Institutional Review
Board policy.
Warm-up procedures
The warm-up routine was a standardized protocol with a
small amount of possible modification (within the specified
range) to more closely match the typical warm-up routine of
the lifter. Warm-ups were as follows: 2-5 repetitions at 35% of
1-RM, followed by 90 seconds rest, 2-3 repetitions at 50%
1-RM, followed by 120 seconds rest, 1-2 repetitions at 65%
1-RM, followed by 150 seconds rest, then 1 repetition at 75%
1-RM, followed by 180 seconds rest. Warm-up loads were
determined using the athletes’ belt-only conventional personal
Isometric Testing Procedures
All isometric testing was completed in a custom designed
power rack that allows fixation at any height. Athletes stood
on a 91.4 x 91.4 cm force plate (Rice Lake Weighing Systems,
Rice Lake, WI) to measure vertical ground reaction forces. Bar
heights for each testing condition were chosen to correspond
to the three key positions achieved in the deadlift and the
isometric mid-thigh pull. For the first height, the center of the
bar was placed at 22.5 cm from the floor to correspond to the
position of the barbell in the start of the deadlift. The second
bar position was placed immediately superior to the patella
from standing. The third corresponded to the same body
position as used in the MTP.
5, 6
The fourth position used the
same bar height as the third, but with a self-selected body
position corresponding to one that would be achieved in a
deadlift. Pilot testing indicated that the fourth height results in
a body position with the bar 4-6 cm from deadlift lockout.
Intra-session test-retest reliability (intraclass correlation,
coefficient of variation, respectively with 90% CI’s for each)
of peak force for each position was excellent: floor: 0.99
(0.98-1.0), 1.2% (0.9%-1.8%), knee: 0.98 (0.96-0.99), 2.0%
(1.5%-2.9%), IMTP: 0.92 (0.80-0.96), 5.0% (3.8%-7.5%),
lockout: 0.88 (0.70-0.94), 4.6% (3.5%-6.9%).
Each condition was performed in order, 1-4, to maintain
standardization among athletes and result in a uniform fatigue.
Pilot testing indicated that forces and perceived difficulty
increased as the athletes used the higher bar positions, thus the
order was chosen to correspond to what was likely least
fatiguing to most fatiguing. The conditions were separated by
10 minutes of rest, during which time the athletes remained
seated. Athletes were secured to the bar using lifting straps and
athletic tape. Each subject assumed the position he would be
using for the pull condition, and once body position was
stabilized (verified by visual monitoring of both the athlete
and force trace), the athlete was given a countdown. Nominal
pre-tension was allowed to minimize slack in the subject’s
body prior to the pull (monitored by force-trace and instruction
to the lifter) to ensure that little or no vertical acceleration of
the athlete occurred. The subject performed two warm-up
attempts separated by 90-120 seconds, each at a subject-
estimated 50% and 75% of maximum. The athletes then
performed 2 to 3 maximal attempts for 3-4 seconds each,
separated by 2-3 minutes. The attempt was terminated when a
plateau or consistent decrease in force was observed. A third
trial was only performed if a ≥250N difference in PF was
observed between trials, a countermovement was observed, or
if the athlete did not follow directions.
The highest observed force from each pull obtained using a
custom analysis program (National Instruments, Austin, TX)
was designated peak force (PF). PF measurements from both
trials were averaged. Peak force was allometrically scaled
(APF) using the equation [y=result∙BdM
Analog data from the force plate were amplified and
conditioned (low-pass at 16 Hz; Transducer Techniques,
Temecula, California). An AD converter (DAQCard-6063E,
National Instruments, Austin, TX) allowed for collection at
1000 Hz and further low-pass filtering using a software-based
Order Butterworth filter at 100 Hz.
Statistical Analysis
For the purpose of comparing kinetic measures at each of
the four pulling positions, a repeated measures ANOVA (RM
ANOVA) was used for each dependent variable considered,
using Bonferroni adjusted paired t-tests (p=0.008) for post-
hoc analysis. RM ANOVA and post-hoc tests were performed
for unscaled and allometrically scaled force. Alpha was
designated at p=0.05. All statistical analysis was performed
using SAS 9.2 (Statistical Analysis System, SAS Institute Inc.,
Cary, NC). Effect sizes were evaluated with the method of
PF and APF measures can be found in Table 1. There was a
significant main effect for PF (F(3,39) = 87.44, p<0.0001),
with η
of 0.871. APF measures were significant for main
effect (F(3,39) = 88.23, p<0.05) with η
of 0.872. Results of
paired t-tests can be found in Table 1. Effect sizes of paired
t-tests for PF and APF were as follows: floor vs. knee, 1.50,
1.97; floor vs. MTP 3.66, 4.22; floor vs lockout 3.04, 3.08;
knee vs. MTP 2.10, 2.80; knee vs. lockout 1.40, 1.52; MTP vs.
lockout 1.23, 1.27.
Athletes produced different PFs at each position (floor, knee,
MTP, lockout). The changing bar height resulted in different
body positions for each pull, and thus a differing ability to
apply force. Interestingly, positions directly related to deadlift
performance (floor, knee, lockout) tended to increase force in
the higher bar positions. PF and APF in the floor position were
significantly less than both the knee and lockout positions
(effect size of large to very large). There was also a significant
Journal of Trainology 2012;1:32-3534
difference between knee and lockout positions (with large
effect size). This finding may be due to a number of reasons.
Brown & Abani
found that horizontal hip moment to the bar
center of mass (COM) decreased with higher bar positions in
the deadlift. While Escamilla et al.
did not test for significant
differences, they reported a trend of decreasing horizontal
moment arm to the barbell COM at the ankle, hip and knee as
the lifter ascended from lift-off to knee passing. This decreased
moment at higher positions may allow for better mechanical
advantage at the hip, thus increasing the resultant generation of
upward force on the bar.
One confounding issue is the fact that two studies have
found that the sticking region occurs at a point roughly around
the knee.
1, 3
Because biomechanical disadvantage causes the
sticking point to occur at a certain range of motion, the total
force generating capability at that position should be reduced
(net extensor moment and force applied to the bar). Therefore,
based on the two aforementioned studies, the force generating
capabilities of deadlifters at the knee position should be less
than the floor position, not more, as was found in the present
study. It is possible that anthropometric characteristics
predispose one to certain sticking points, but no known
research exists to assert this. Another possibility is that in the
Escamilla et al.
and Hales et al.
studies the lifters were using
a powerlifting deadlift suit. If this was the case, then the
sticking regions of the lifts may be higher due to the assistance
afforded the lifter by lifting suits.
Also possible is that the
position used by athletes in the present study is different than
what athletes use in a maximal deadlift. If the isometric pull
allows for a more ideal body position than is attained during
the deadlift, greater forces might be achieved, thus
representing a possible limitation of this study. Further
research should confirm this.
It is interesting that the MTP position allowed the lifters to
produce the greatest amount of force, despite the lockout
position being more similar in position to the deadlift. The
lifters generally performed well in the lockout position
(understandable given that they regularly train a movement
that requires it, i.e. the deadlift, and do not regularly train in
the MTP position); therefore the MTP position must provide a
substantial mechanical advantage that overcomes even the
frequent training in the deadlift-specific position. The greater
Table 1. Results of isometric testing and paired t-tests
Measure Position Mean ± SD Significance
Peak Force (N)
Floor 3380.0 ± 377.0 †, ‡, §
Knee 4093.0 ± 559.0 *, ‡, §
Mid-Thigh Pull 5829.0 ± 867.0 *, †, §
Lockout 4910.0 ± 605.0 *, †, ‡
Allometrically Scaled
Peak Force (
Floor 148.5 ± 12.7 †, ‡, §
Knee 179.8 ± 18.6 *, ‡, §
Mid-Thigh Pull 256.4 ± 33.9 *, †, §
Lockout 216.6 ± 28.6 *, †, ‡
* = significantly different than floor position p <0.001
† = significantly different than knee position p <0.001
‡ = significantly different than MTP position p <0.001
§ = significantly different than lockout position p <0.001
Figure 1. Example of lifter in MTP position (left) compared to lockout (right)
Beckham et al. Isometric Strength of Powerlifters in Key Positions of the Conventional Deadlift 35
forces produced in the MTP position over the other three
positions may be explained by a number of things. First,
simple observation showed a marked difference in position
even between the MTP and the position of second greatest
force (lockout). The MTP position is rather upright, with the
knees bent. Powerlifters, in mimicking the deadlift, are in a
relatively straight legged position and somewhat bent over the
bar. Figure 1 shows an example of the differing position for
one of the athletes. The lockout position likely creates a
greater moment on the lower back and hips, which may limit
performance. The greater knee bend used in the MTP position
probably provides a force-production advantage, as the
powerful extensor forces of the quadriceps muscles are used to
a greater extent. The gluteus maximus may also be in a more
favorable position for resultant force production against the
bar, assuming a smaller hip moment, as was found in Brown &
and Escamilla et al.
Powerlifters in this study generated substantially different
amounts of force in each position. Changing mechanical
advantages probably contribute to the difference in forces, but
further research is needed to confirm this. Despite the
advantage of regular training in the deadlift-specific positions
(floor, knee and lockout), lifters still generated far more force
in the MTP. The MTP appears to represent the position of
greatest force output, even in lifters who train regularly in the
other positions. Lower force production capabilities in the
lower positions represent a limiting factor for deadlift
performance, thus an emphasis in training of the lower ranges
of motion of the deadlift may elicit greater gains.
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... Specifically, multijoint isometric exercises are used to evaluate the maximum force and rapid forcegenerating capacity in athletes (7,8,9). Beckham et al., (6) analyzed fourteen powerlifters who performed isometric deadlift pulls on a force plate at 3 key positions (at the floor, just above the patella, and 5-6 cm short of lockout) and in the midthigh pull position. The authors reported the force generated in the midthigh pull position was significantly higher than any other position. ...
... The results for the maximal isometric force (MIF) showed that the high barbell position (75% LLH) produced higher values (18%) when compared to the low barbell position (25% LLH) during the deadlift exercise and corroborated with our hypothesis that the higher barbell position has greater effects on maximal isometric actions during the deadlift exercise [75% LLH: 2,278.6 ± 741.0N (ratioMIF = 2.94 ± 1.1) and 25% LLH: 1,873.0 ± 715.9N (ratioMIF = 2.42 ± 1.1), p < 0.001]. Additionally, the studies of Beckham et al., (6) and Bartolomei et al.,(4) corroborated with the present results, however with different training statuses. Beckham et al., (6) analyzed fourteen powerlifters who performed isometric deadlift pulls on a force plate at 3 key positions (at the floor, just above the patella, and 5-6 cm short of lockout) and in the midthigh pull position. ...
... Additionally, the studies of Beckham et al., (6) and Bartolomei et al.,(4) corroborated with the present results, however with different training statuses. Beckham et al., (6) analyzed fourteen powerlifters who performed isometric deadlift pulls on a force plate at 3 key positions (at the floor, just above the patella, and 5-6 cm short of lockout) and in the midthigh pull position. The authors reported the force generated in the midthigh pull position (5,829.0 ...
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International Journal of Exercise Science The primary purpose of this study is to examine the effect of two different deadlift barbell height positions on maximal isometric force and subsequent maximal squat jump performance in recreationally-trained men. Fifteen young, healthy, recreationally-trained men (age: 24.7 ± 3.5years, height: 177.1 ± 7.9cm, and total body mass: 81.2 ± 9.8kg) volunteered to participate. All participants performed maximal squat jumps (MSJ) at 90º of knee flexion before (pre-test) and after 4-min (post-test) performing the deadlift exercise using maximal isometric force (MIF) and MIF normalized by body mass (ratioMIF) in two barbell height positions (25% and 75% of the lower limb height, LLH) in a randomized and counterbalanced order. A paired-sample t-test was used to test differences in MIF and ratioMIF between 25% LLH and 75% LLH. Two-way ANOVAs were used for positions (25% LLH and 75% LLH) and time (pre-and post-test) for all dependent variables with an alpha of 5%. Differences were found for MIF and ratioMIF during the deadlift between 25% LLH and 75% LLH (p < 0.001). There was observed an increase in impulse between pre-and post-test only at 75% LLH (p < 0.001), decrease in time to peak force between pre-and post-test only at 75% LLH (p < 0.001), and increase in peak force between pre-and post-test at 75% LLH (p = 0.029). The present results showed that the maximal isometric deadlift exercise at 75% LLH (midthigh) improves subsequent jump performance of the squat jump recreationally-trained men.
... However, several investigations have examined isometric testing across multiple positions of the corresponding dynamic exercise, including the deadlift (Bartolomei et al., 2019;Beckham et al., 2012;Malyszek et al., 2017;Miller, 2020), back squat (Bazyler, Beckham, & Sato, 2015;Marcora & Miller, 2000) and bench press (Murphy, Wilson, Pryor, & Newton, 1995). A common finding between these investigations was that the longer muscle length testing position elicited a comparatively smaller peak force than at the shorter muscle length position. ...
... The net PkF was collected and the average value of all the three trials was used for the analysis. Testretest reliability for IMTP and IPSP for PF was ICC = 0.97, CV 2.76% and ICC = 0.98, CV 1.3% respectively, and are consistent with previous reports (Beckham et al., 2012;Haff et al., 2005;Joffe & Tallent, 2020;Stone et al., 2005). ...
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This investigation compared the maximal isometric force capacity between the start position of the first pull (IPSP) and isometric mid-thigh pull (IMTP), and their relationship with weightlifting competition performance in twenty national and international, male and female weightlifters. Isometric strength assessment and competition performance data collected as part of the routine sport science services of a national weightlifting performance programme were used for this study. Differences in isometric peak force (PkF) and allometrically scaled peak force (PkFa) between the IPSP and IMTP were evaluated using a paired-samples t-test. The relationships between absolute and allometrically scaled IPSP, IMTP, Total (TOT), Snatch (SN) and Clean & Jerk (CJ) variables were analysed using Pearson's Product-Moment Correlation. Fisher's r-to-z transformation was used to statistically compare the correlation values between the IPSP and IMTP with weightlifting performance measures. The IMTP PkF and PkFa were significantly greater than the IPSP PkF and PkFa, respectively, across combined (COM), male (M) and female (F) groups (p = < 0.001). However, the IPSP PkF exhibited significantly greater correlations with SN (r = 0.94 vs. 0.83, p < 0.05) and TOT (r = 0.95 vs. 0.86, p < 0.05) than the IMTP PkF in the COM group. In addition, the IPSP PkFa exhibited a significantly greater correlation with allometrically scaled snatch (SNa) (r = 0.83 vs. 0.51, p < 0.05) than the IMTP PkFa in the COM group. No significant correlations were observed between the IPSP PkFa and IMTP PkFa across M, F and COM groups. These findings suggest that the maximal force capacity in the IPSP is a greater determinant of weightlifting performance than in the IMTP, however, each may be representative of independent neuromuscular qualities. Coaches and practitioners working with weightlifters may consider implementing the IPSP assessment in addition to the IMTP to evaluate the strength characteristics specific to the different phases of the pull.
... Countermovement jump testing demonstrates content and face validity according to associations with occupational (i.e., military) and sport performances (22,25,37), power output (45), resiliency to fatigue (18,42,46), and injury risk (38). Additional assessments include isometric testing (i.e., no physical movement; isometric mid-thigh pull [IMTP]), which correlates with dynamic strength (2,8), the drop jump, which identifies an individual's ability to land appropriately and explosively reaccelerate under various conditions (28,30), and the squat jump, which removes all eccentric actions to isolate power production capabilities without support from elastic properties (19). Each aforementioned test demonstrates unique force-time curves typically grouped as follows: dynamic movements starting on force plates with no eccentric action or countermovement (e.g., squat jump), dynamic movements starting on the force plate with a countermovement (e.g., countermovement jump, plyometric push-up), dynamic movements starting off the force plate (e.g., drop jump or push-up), and isometric strength tests (e.g., IMTP, isometric bench). ...
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With the growing prevalence of commercial force plate solutions providing automated force-time curve analysis, it is critical to understand the level of agreement across techniques. Thus, this study directly compared commercial and custom software analyses across force-time curves. Twenty-four males and females completed six trials of countermovement, squat, and drop jumps, and isometric mid-thigh pulls on the same force plate. Vertical ground reaction forces were analyzed by automated software from Vald Performance, Hawkin Dynamics, and custom MATLAB scripts. Trials were visually assessed to verify proper landmark identifications. Systematic and proportional bias among analyses were compared via least products regressions, Bland Altman plots, and percent error. Hawkin Dynamics had subtle differences in analysis procedures and demonstrated low percent errors across all tests (<3% error), despite demonstrating systematic and proportional bias for several metrics. ForceDecks demonstrated larger percent differences and greater biases for several metrics. These errors likely result from different identification of movement initiation, system weight, and integration techniques, which causes error to subsequent landmark identifications (e.g., braking / propulsive phases) and respective force-time metrics. Many metrics were in agreement between devices, such as isometric mid-thigh pull peak force consistently within 1 N across analyses, but some metrics are difficult and incomparable across software analyses (i.e., rate of force development). Overall, many metrics were in agreement across each commercial software and custom MATLAB analyses after visually confirming landmarks. However, due to inconsistencies, it is important to only compare metrics that are in agreement across software analyses when absolutely necessary.
... Prior to completion of the IMTP correct body position for each participant was determined and repeated for each test completed. Bar height was set to replicate the 2nd pull position during the clean, adjusting to ensure that optimal knee (125-145 • ) and hip (140-150 • ) angles were set, due to body position being shown to significantly affect force generation [4,14,15,26]. Angles were quantified utilising a hand-held goniometer. The goniometer was placed on the lateral femoral condyle, with upper arm following the line of the femur and lower arm tracing the line of the fibula to quantify knee angle. ...
Objectives. — The purpose of the present study was to analyse the association between grip strength and performance of the standardised protocol of the isometric mid-thigh pull (IMTP)test. Methods. — In total, 31 elite premier league footballers completed test—retest measures of peak force (PF) grip strength and IMTP, measures were taken 7 days apart. Post-completion of the test—retest 3 maximal IMTP and bilateral grip strength measures were taken. Mean PF was calculated bilaterally for each assessment. Linear relationships were determined for test—retest and Grip Strength Test (GST) and IMTP PF output. Results. — Test—retest of the GST and IMTP displayed significant almost perfect correlations bilaterally (P ≤ 0.001, r = 0.92—0.94, CI = 0.85—0.96). Bilateral moderate-large significant correlations were also identified between grip strength and IMTP PF (P ≤ 0.05, r = 0.54—0.72,CI = 0.30—0.86). Conclusions. — GST and IMTP are reliable and repeatable measures. Findings in the present study indicate consideration must be given to the influence of grip strength on maximal IMTPPF output. Previous literature describes standardisation procedures for IMTP performance. Pre-completion of IMTP measures in elite footballers, performance practitioners should consider assessment of the athlete’s grip strength despite the use of lifting straps.
... Maximizing force production and the ability to generate that force with a high velocity is critical to reaching a high level of performance [29]. Training programs that aim to increase peak force and peak power output in order to contribute to an increased performance outcomes in powerlifting, weightlifting, sprinting, and jumping are well-established in the literature [30,31] For example, the performance measures of isometric mid-thigh pull (IMTP) are correlated with a variety of dynamic performance movements [32][33][34][35]. Therefore, utilizing IMTP may be useful to assess force production. ...
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... For example, isometric strength testing via the isometric mid-thigh pull (IMTP) is a preferable means to analyze maximal force production rather than 1-RM testing, as IMTPs are relatively simple to administer, time efficient, reduce the risk of injury, and possess high degrees of reliability under the correct testing conditions [6][7][8][9]. Additionally, despite being an isometric test (i.e., no physical movement or displacement of body segments), measures from the IMTP correlate to performance in dynamic movements of powerlifting [10,11], weightlifting [12], sprinting [13], and jumping [14,15]. Another test, the countermovement jump (CMJ), is used (often in conjunction with IMTPs) for athlete testing to identify changes in power performance [16], resiliency to fatigue [17][18][19], and risk for injury [20]. ...
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Abstract: The purpose of this study was to evaluate intrasession reliability of countermovement jump (CMJ) and isometric mid-thigh pull (IMTP) force–time characteristics, as well as relationships between CMJ and IMTP metrics. Division I sport and club athletes (n = 112) completed two maximal effort CMJ and IMTP trials, in that order, on force plates. Relative and absolute reliability were assessed using intraclass correlation coefficients (ICCs) > 0.80 and coefficients of variation (CVs) < 10%. Intrasession reliability was acceptable for the majority of the CMJ force–time metrics except for concentric rate of force development (RFD), eccentric impulse and RFD, and lower limb stiffness. The IMTP’s time to peak force, instantaneous force at 150 ms, instantaneous net force, and RFD measures were not reliable. Statistically significant weak to moderate relationships (r = 0.20–0.46) existed between allometrically scaled CMJ and IMTP metrics, with the exception of CMJ eccentric mean power not being related with IMTP performances. A majority of CMJ and IMTP metrics met acceptable reliability standards, except RFD measures which should be used with caution. Provided CMJs and IMTPs are indicative of distinct physical fitness capabilities, it is suggested to monitor athlete performance in both tests via changes in those variables that demonstrate the greatest degree of reliability.
... 72 For readers interested in the use of the IMTP with weightlifters, a detailed review was recently published by Stone et al. 117 Despite the IMTP positioning being specific to the WL movements, strong correlations have been found between it and both the squat 28,90,91 and deadlift; 32 however, these studies were not conducted using powerlifters as subjects. Beckham et al, 14 using competitive powerlifters, compared the IPF performed in different positions that corresponded closer to a conventional deadlift to the IMTP. However, to the authors' knowledge, no longitudinal investigation has used this type of testing with powerlifters. ...
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Barbell strength sports such as weightlifting (WL) and powerlifting (PL) have been slow to adopt modern athlete monitoring practices. Obstacles such as a lack of resources, experience, and knowledge dealing with athlete monitoring stand in the way of their implementation into these sports. Therefore, the purposes of this review are: 1) to synthesise the scientific literature most relevant to the monitoring of strength athletes, and 2) to provide practical recommendations to the strength sport coach for implementing an athlete monitoring programme.
... Reason being, isometric tests are relatively simple to administer and time efficient, reduce the risk of injury in comparison to one-repetition maximum testing, and are very reliable under the correct and consistent conditions [42][43][44]. Additionally, even though the IMTP is isometric by nature (it does not involve physical movement or displacement of body segments), measures from the IMTP correlate to performance in dynamic movements of powerlifting [86], weightlifting [87], sprinting [88], and jumping [89]. Most importantly, the IMTP and isometric squat do not require the extensive familiarization periods that may be associated with a traditional one-repetition maximal test, which requires specific skill development in the weight room (e.g., becoming highly proficient in the back squat, bench press, deadlift, etc.). ...
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A necessarily high standard for physical readiness in tactical environments is often accompanied by high incidences of injury due to overaccumulations of neuromuscular fatigue (NMF). To account for instances of overtraining stimulated by NMF, close monitoring of neuromuscular performance is warranted. Previously validated tests, such as the countermovement jump, are useful means for monitoring performance adaptations, resiliency to fatigue, and risk for injury. Performing such tests on force plates provides an understanding of the movement strategy used to obtain the resulting outcome (e.g., jump height). Further, force plates afford numerous objective tests that are valid and reliable for monitoring upper and lower extremity muscular strength and power (thus sensitive to NMF) with less fatiguing and safer methods than traditional one-repetition maximum assessments. Force plates provide numerous software and testing application options that can be applied to military's training but, to be effective, requires the practitioners to have sufficient knowledge of their functions. Therefore, this review aims to explain the functions of force plate testing as well as current best practices for utilizing force plates in military settings and disseminate protocols for valid and reliable testing to collect key variables that translate to physical performance capacities.
Both weightlifting belts and wrist straps are commonly used weightlifting training aids but their effects on deadlift kinematics and performance were still not known. This study examined the effects of weightlifting belts and wrist straps on the kinematics of the deadlift exercise, time to complete a deadlift and rating of perceived exertion (RPE) in male recreational weightlifters. This study used a repeated-measures, within-subjects design. Twenty male healthy recreational weightlifters (mean age ± standard deviation = 23.1 ± 2.5 years) were recruited from 2 local gyms and the Education University of Hong Kong between January and April 2021. All participants used various combinations of belt and straps during a conventional deadlift. The hip and knee flexion, cervical lordosis, thoracic kyphosis and lumbar lordosis angles and time to complete a deadlift were measured using video analysis software. RPE was also recorded. Wearing both a belt and wrist straps was found to reduce knee flexion angle (P < .001), but not hip flexion angle (P > .05), during the setup phase of the deadlift compared to wearing no aid. Wearing straps alone exaggerated thoracic kyphosis in the lockout phase of the deadlift compared to wearing a belt alone (P < .001). No changes were seen in cervical and lumbar lordosis angles when using any or both of the weightlifting aids. Additionally, the participants completed deadlifts faster when wearing both a belt and straps (P = .008) and perceived less exertion when wearing a belt and/or straps (P < .001). Weightlifting belts and wrist straps, when using together, have positive effects on the kinematics of deadlift, time to complete a deadlift and RPE in male recreational weightlifters. Trainers should recommend the use of a belt and straps together, but not straps alone, to recreational weightlifters when performing deadlift training.
The testing and assessment of resistance training exercises is a fundamental aspect for coaches and athletes. Through the force-time data measured by force plates, we have the possibility to calculate velocity, displacement, work, and power values of the centre of mass. This chapter has a theory section where we explain why force plates are useful to evaluate isometric and ballistic actions during resistance training. Also, we explore how we can obtain velocity, displacement, power and work variables from force-time data through the impulse method. The chapter contains a practice section where we response some key questions when setting up a force plate to assess athletes’ physical performances. Then, we describe how to perform an Isometric Mid Thigh Pull Test (IMTP) and a Countermovement Jump Test (CMJ). We explain how we can obtain biomechanical variables from both tests and we discuss about the biomechanical variables that provide important information to interpret correctly the IMTP and CMJ tests. Finally, we added a filling the gap section where we provide several recommendations on how to implement the evidence-based theory in real life applied sports environments.
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Study Design: Systematic Literature Review Objective: 1) to identify the overall trends of association of isometric strength and dynamic activities 2) to summarize the findings of reported literature on the relationship of Isometric strength and dynamic performance. Background: Isometric Strength measures have been used for many years to predict dynamic performance but there are considerable controversies regarding the potential of isometric muscle assessments to predict dynamic performance. Although researches have been conducted to study the relationship, it is important that the current available literature be reviewed to summarize the findings for clinical use. Methods: A systematic review was conducted to identify the published studies that correlated the Isometric and dynamic variables. Studies were searched using electronic databases and the methodological quality of each study was assessed using the modified Downs and Black 13 point criteria. Results: Fifteen studies met the inclusion criteria. Marked difference in the methodology and variables used for isometric and dynamic activities were observed. Most studies correlated isometric strength assessments to dynamic activities or dynamic strength measurements. Discussion & Conclusion: Although there are conflicting opinions regarding the use of isometric measurements, most studies in our review report moderate to strong correlation between Isometric strength and dynamic performances specially those which involve large amounts of force and explosive power
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To investigate the relationship between maximum strength and differences in jump height during weighted and unweighted (body weight) static (SJ) and countermovement jumps (CMJ). Sixty-three collegiate athletes (mean +/- SD; age= 19.9 +/- 1.3 y; body mass = 72.9 +/- 19.6 kg; height = 172.8 +/- 7.7 cm) performed two trials of the SJ and CMJ with 0 kg and 20 kg on a force plate; and two trials of mid-thigh isometric clean pulls in a custom rack over a force plate (1000-Hz sampling). Jump height (JH) was calculated from flight time. Force-time curve analyses determined the following: isometric peak force (IPF), isometric force (IF) at 50, 90, and 250 ms, and isometric rates of force development (IRFD). Absolute and allometric scaled forces, [absolute force/(body mass(0.67))], were used in correlations. IPF, IRFD, F50(a), F50, F90, and F250 showed moderate/strong correlations with SJ and CMJ height percent decrease from 0 to 20 kg. IPF(a) and F250(a) showed weak/moderate correlations with percent height decrease. Comparing strongest (n = 6) to weakest (n = 6): t tests revealed that stronger athletes (IPF(a)) performed superior to weaker athletes. Data indicate the ability to produce higher peak and instantaneous forces and IRFD is related to JH and to smaller differences between weighted and unweighted jump heights. Stronger athletes jump higher and show smaller decrements in JH with load. A weighted jump may be a practical method of assessing relative strength levels.
The purpose of this study was to document the differences in kinematics between the Sumo and conventional style deadlift techniques as performed by competitive powerlifters. Videotapes of 19 conventional and 10 Sumo contestants at two regional New Zealand powerlifting championships were analyzed. It was found that the Sumo lifters maintained a more upright posture at liftoff compared to the conventional lifters. The distance required to lift the bar to completion was significantly reduced in the Sumo technique. No significant difference was found between the techniques as to where the sticking point (first decrease in vertical bar velocity) occurred. (C) 1996 National Strength and Conditioning Association
Based on isometric scaling principles, a relationship was derived that states that the mass a subject can lift is proportional to body mass2/3. This study examined the validity of this relationship by fitting it to the world lifting records from different mass classes. The exponent was 0.64 for Olympic lifting and 0.65 for power lifting, giving a good match to the theory. The derived relationship was then used to examine the scaling of weightlifting performance. Weightlifting data were scaled by the Schwartz formula, and also by dividing total mass lifted by either subject mass or by subject mass2/3 (isometric scaling). The isometric scaling method was the most appropriate as it varied the least across mass classes. It is proposed that scaling based on isometric principles should be used if interindividual or intergroup weightlifting performances are to be compared. (C) 1999 National Strength and Conditioning Association
Eight trained men were used to compare isometric and dynamic force-time variables. Subjects performed maximum isometric and dynamic pulls at 80% (DP80), 90% (DP90), and 100% (DP100) of their current 1-RM power clean from a standardized postion on a 61.0- x 121.9-cm AMTI force plate. Isometric peak force showed moderate to strong correlations with peak force during DP80, DP90, and DP100 (r = 0.66, 0.77, and 0.80, respectively). Isometric rate of force development showed moderate to strong correlations with dynamic peak force during DP80, DP90, and DP100 (r = 0.65, 0.73, and 0.75, respectively) and was strongly correlated with peak dynamic rate of force development during DP80, DP90, and DP100 (r = 0.84, 0.88, and 0.84, respectively). This suggests that the ability to exert both isometric and dynamic peak force shares some structural and functional foundation with the ability to generate force rapidly. (C) 1997 National Strength and Conditioning Association
Many individuals involved in the sport of powerlifting believe that the squat and deadlift have such similar lifting characteristics that the lifts yield comparable training results. The aim of this study was to compare and contrast biomechanical parameters between the conventional style deadlift and the back squat performed by 25 lifters competing in regional powerlifting championship. The 3-dimensional analysis incorporated 4 60 Hz synchronized video cameras for collecting data from 25 participants. Parameters were quantified at the sticking point specific to each lift. Kinematic variables were calculated at the hip, knee, and ankle. Paired (samples) t-tests were used to detect significant differences in the kinematic mean scores for the different lift types. The statistical analysis revealed significant differences exist between the squat (0.09 m/s) and the deadlift (0.20 m/s) vertical bar velocities. Differences were found for angular position of the hip, knee, and ankle between lifts. The sticking point thigh angles were quantified as 32.54 +/- 3.02 and 57.42 +/- 4.57 for the squat and deadlift, respectively. Trunk angles were 40.58 +/- 6.29 (squat) and 58.30 +/- 7.15 (deadlift). The results indicate the back squat represents a synergistic or simultaneous movement, whereas the deadlift demonstrates a sequential or segmented movement. The kinematic analysis of the squat and the conventional deadlift indicate that the individual lifts are markedly different (p < 0.01), implying that no direct or specific cross-over effect exists between the individual lifts.
This study documented characteristics of the dead lift of teenage lifters. Films of 10 "skilled" and 11 "unskilled" contestants in a Michigan Teenage Powerlifting Championship provided data for analysis. Equations of motion, force, and moments were developed for a multisegment model of the lifters' movement in the sagittal plane and applied to the film data. Analysis was limited to 1) body segment orientations, 2) vertical bar accelerations, 3) vertical joint reaction forces, 4) segmental angular accelerations, 5) horizontal moment arms of the bar to selected joints, and 6) intersegmental resultant moments. Significant differences (P less than 0.05) in body segment orientation indicated a more upright posture at lift-off in the skilled group. Maximum vertical bar acceleration and angular acceleration of the trunk tended to occur near lift-off in the skilled lifters. The unskilled subjects demonstrated greater variability and magnitude in linear and angular acceleration parameters. In all lifters, maximum vertical force was experienced at the ankle joint. Within each subject, the hip joint experienced the greatest torque because of the relatively large horizontal moment arm of the bar (dominant mass in the system) to this joint. In all subjects, the magnitude of the mass lifted, and not the technique, was the primary determinant in the intersegmental resultant moment acting at the hip and the vertical force experienced at the ankle, knee, and hip joints.
Strength athletes often employ the deadlift in their training or rehabilitation regimens. The purpose of this study was to quantify kinematic and kinetic parameters by employing a three-dimensional analysis during sumo and conventional style deadlifts. Two 60-Hz video cameras recorded 12 sumo and 12 conventional style lifters during a national powerlifting championship. Parameters were quantified at barbell liftoff (LO), at the instant the barbell passed the knees (KP), and at lift completion. Unpaired t-tests (P < 0.05) were used to compare all parameters. At LO and KP, thigh position was 11-16 degrees more horizontal for the sumo group, whereas the knees and hips extended approximately 12 degrees more for the conventional group. The sumo group had 5-10 degrees greater vertical trunk and thigh positions, employed a wider stance (70 +/- 11 cm vs 32 +/- 8 cm), turned their feet out more (42 +/- 8 vs 14 +/- 6 degrees). and gripped the bar with their hands closer together (47 +/- 4 cm vs 55 +/- 10 cm). Vertical bar distance, mechanical work, and predicted energy expenditure were approximately 25-40% greater in the conventional group. Hip extensor, knee extensor, and ankle dorsiflexor moments were generated for the sumo group, whereas hip extensor, knee extensor, knee flexor, and ankle plantar flexor moments were generated for the conventional group. Ankle and knee moments and moment arms were significantly different between the sumo and conventional groups, whereas hip moments and moments arms did not show any significantly differences. Three-dimensional calculations were more accurate and significantly different than two-dimensional calculations, especially for the sumo deadlift. Biomechanical differences between sumo and conventional deadlifts result from technique variations between these exercises. Understanding these differences will aid the strength coach or rehabilitation specialist in determining which deadlift style an athlete or patient should employ.