Journal of Strength and Conditioning Research Publish Ahead of Print DOI: 10.1519/JSC.0000000000000986
Title: KINEMATICS AND KINETICS OF MULTIPLE SETS USING LIFTING STRAPS DURING DEADLIFT TRAINING Running Read: Kinematics of deadlift with lifting straps Laboratory: Federal University of Pelotas, Superior School of Physical
Authors, departments and institutions:
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Victor Silveira Coswig1,2
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Diogo Freitas1 Paulo Gentil3
David Hideyoshi Fukuda4
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Fabrício Boscolo Del Vecchio1,5
1 - Superior School of Physical Education, Federal University of Pelotas
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2 - Faculty Anhanguera of Pelotas
3 - College of Physical Education, University of Brasilia
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4 - Institute of Exercise Physiology & Wellness, University of Central Florida 5 - Combat Sports and Martial Arts Research Group, University of São Paulo
Corresponding Author: Victor Silveira Coswig 625, Luís de Camões Street, Pelotas - RS, Brazil- 96055-630 Phone number: (55) 53 3273-2752; E-mail:
[email protected]
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ABSTRACT
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The deadlift is a fundamental exercise used in the development of whole body strength
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and a common element in resistance training programs for all levels. However, many
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practitioners report the fatigue of forearm muscles and possibly a lack of grip strength as
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obstacles to exercise performance, which may lead to the use of ergogenic aids, such as
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lifting straps. The objective of the present study was to evaluate kinematic variables during
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the execution of multiple sets of deadlift with (WS) and without (NS) lifting straps. Eleven
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subjects (25 ± 3.3 years) with an average of 4 ± 2.6 years of resistance training experience
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were enrolled in the study. After the one-repetition maximum (1RM) test with and without
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straps, subjects performed separate trials of three sets to failure at 90% of 1RM in a
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counterbalanced fashion. WS resulted in lower speed [0 to -25%] (-3 to -10%), and greater
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force (20 to 28%) and duration (con: 0 to 13%) when compared to NS. Therefore, it is
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concluded that the use of straps directly influences exercise performance that requires
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manual grip strength, increasing the amount of work performed by the target muscles.
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KEY-WORDS: Muscle strength; Resistance training; Weight lifting
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INTRODUCTION
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The deadlift is a multi-joint exercise widely used in several training modalities (9, 26,
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27). It is critical for strength development (2, 3), and is a primary component of
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powertlifting competitions, along with bench press and squat (8). Although high loads can
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be used in the deadlift, the lifter's ability to handle the bar, via grip strength, is often a
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limiting factor for the amount of weight that can be lifted (1, 9).
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It has been previously suggested that training load has a fundamental role on maximum number of repetition
performance and greater loads have been shown to
optimize strength gains (13, 24, 28). Therefore, in order to enhance training loads and
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reduce fatigue of the forearm muscles during the deadlift exercise, many strategies have
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been suggested, such as, the use of an inverted grip, alteration of bar thickness,
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magnesium powder and use of lifting straps (1, 20). The lifting straps are attached to the
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lifter’s wrists and wrapped around the barbell or the handle of the resistance training
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equipment until fully tightened or secured (24). With lifting straps, the limitations due to grip
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strength become less pronounced and, theoretically, an associated load increase would
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promote greater activation of the targeted muscles (21, 23). Although one previous
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investigation has shown that the use of LS provided a superior maximum number of
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training, such as maximum strength, power and amplitude.
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repetitions during cable pulldown exercise at 75% of 1RM with a neutral grip (29), it is not known whether the use of this implement modifies other variables related to strength
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The ergogenic potential of the use of lifting straps is multifactorial (20) and has been
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described through their impact on maximum number of repetitions as influenced by: the
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modality of the exercise (free weights or machines), the volume of muscle mass involved,
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and percentage of 1RM utilized during resistance training (13). Although the magnitude of
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physiological adaptations are clearly related to these variables, they may also be
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influenced by the speed, amplitude of movement, and time under tension (3, 8, 15, 24).
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Therefore, the objective of this study was to evaluate the effects of using lifting straps on
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different kinematic variables during multiple deadlift sets. The hypothesis was that these
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variables would be altered when compared to RT without lifting straps.
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Experimental Approach to the Problem
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METHODS
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This study utilized an experimental cross-over design, in which the independent
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variable was the presence (WS; with straps) or absence (NS; no straps) of lifting straps
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during execution of the deadlift. The participants performed specific 1RM tests for each
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condition (NS and WS) and, subsequently, executed three sets to failure at 90% 1RM
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based on the corresponding 1RM values, with 2 minutes of rest between them. The WS
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and NS conditions interspaced by 48 hours, in a randomized counterbalanced design. The
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dependent variables included the 1RM deadlift values as well as the maximum number of
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repetitions, kinematic variables (power, force, amplitude, time, and speed) for concentric
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muscle actions, heart rate response, and rating of perceived of exertion (RPE) for each set
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of deadlift trials.
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Subjects
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The study participants were physically-active, apparently healthy men, (age: 25.0 ±
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3.3 years old; body mass: 86.0 ± 7.6 kg; stature: 177.9 ± 4.7 cm; body fat percentage: 9.0
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± 3.1%) with 4.0 ± 2.6 years of resistance training experience and a weekly training
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frequency of 4.0 ± 0.8 days with a minimum of three consecutive months of resistance
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training experience. Subjects were excluded if any of the following criteria were identified:
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a history of injury or pain during this exercise within the last three months, use of controlled
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medications under medical supervision, or engagement in activities with a significant grip
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strength requirement, such as Brazilian jiu-jitsu, judo and mountaineering (29).
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Study procedures The study took place over three testing sessions, each separated by a 48-hour
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interval. The first consisted of the preliminary testing and familiarization with the
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instruments and procedures. During the second and third sessions, the experimental
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protocols were conducted in a randomized order.
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Day 1 - After signing the informed consent (approval number 037/2011 by the local ethical
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committee), the volunteers completed a medical history questionnaire. Skinfold thickness
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was measured with a skinfold caliper (CESCORF®, Porto Alegre, Brazil; with accuracy of
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0.1 mm) by a trained and experienced evaluator at the chest, abdomen and thigh
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according to Jackson & Pollock protocol (14). From these data, body density (14) and
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body fat percentage (25) were calculated. In addition, subjects were familiarized with the
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deadlift exercise, as previously standardized (7), and the maximum load testing (1RM)
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protocol was performed as indicated by Ratamess et al (20). During the 1RM testing
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procedures, subjects were also familiarized with the 0-10 RPE scale (24).
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Days 2 and 3 - After a five-minute general warm-up on a cycle ergometer at a self-selected
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resistance and cadence, subjects executed the following procedures under both the WS
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and NS conditions: i) evaluation of 1RM in order to identify the maximum load employed in
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the subsequent training session and, after a minimum rest interval of 3 minutes (9, 20), ii)
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the training session comprised of 3 maximum number of repetition sets of the deadlift
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exercise, at 90% of 1RM while attempting to maximize speed of movement and range of
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motion (9, 26, 27), separated by 2-minute rest intervals. Subjects completed the
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procedures in a randomized, counterbalanced order with respect to either the WS or NS
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conditions During execution of the deadlift, subjects used a HR monitor (Polar®, model
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RS800CX) to identify the HR responses before and after each set. Immediately after
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execution of each maximum number of repetitions deadlift set, general (RPE-G) and
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muscle-specific (RPE-M) RPE scale ratings were recorded (24). Specifically for RPE-M,
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the subjects were asked to rate the perceived strain related to the exercising muscles (20).
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Deadlift methods
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For both 1RM testing and training session, subjects gripped the barbell with a
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closed double pronated grip without chalk, using a 220 cm bar (Olympic-type;
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PHYSICUS®, Brazil). To normalize grip width for different sized individuals, the shoulder
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width was used to determine grip width. The deadlift technique was initiated with a
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shoulder width stance and flexed knees and hips while maintaining a flat back or slight
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lordotic arch and executed in manner outlined elsewhere (7) in which a single repetition
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was considered complete after full knee and hip extension were attained.
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1RM Test
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the subjects executed 5-10 deadlift repetitions at 40-60% of perceived 1RM. After a one-
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minute rest interval, 2-3 additional repetitions were performed at 60-80% of perceived 1RM
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to complete the warm-up. During the testing trial, 3-4 maximum attempts (of a single
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repetition) separated by 2 minutes were conducted to determine the 1RM load (20).
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The 1RM test was preceded by general warm-up on a cycle ergometer for 5
minutes, at a self-selected resistance and cadence (16, 24). Then, as specific warm-up,
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Testing Testing consisted of three successive sets of deadlifts performed until failure at 90%
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of 1RM, separated by 2-minutes intervals. Subjects were oriented to lift at maximal speeds
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through the full range of motion (9, 13). Only the repetitions that complied with previous
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standardization procedures regarding the execution and range of motion were deemed
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acceptable. The maximum number of repetitions for each set was recorded when a subject
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was unable to support the load or paused longer than 2s (13, 20) as analyzed by two
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independent assessors, with more than five years of experience in resistance training.
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Measurement of kinematic variables
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During the successive training sets, a linear potentiometer (Peak Power, CEFISE®,
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Nova Odessa, Brazil) connected to the bar measured both displacement and time during
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the deadlift repetitions After accounting for the specific load utilized, Peak Power software
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4.0 (CEFISE®, Nova Odessa, Brazil) was used to calculate average and peak power (w),
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average and peak applied force (N), amplitude (mm), duration (ms) and speed (m/s) in the
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concentric and eccentric phases for each lift. Previous studies have shown this method to
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be both valid and reliable (17, 22), with accuracy within 0.10-0.25% during the concentric
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phase, reliability error of 0.02% ,and r values for test-retest reliability of .86 to .99 (11). In
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addition, data from our laboratory showed that the procedures have high test-retest
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Statistical analyses
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reliability for the following variables: amplitude (ICC = 0.87), effort duration (ICC = 0.84) and power output (ICC = 0.82).
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The Shapiro Wilk test was used for data normality verification. The descriptive data
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are presented as mean and standard deviation (SD). For 1RM comparisons between the
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NS and WS conditions, a one way analysis of variance was used, with Greenhouse-
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Geisser correction when Mauchly’s test of sphericity indicated a violation of this
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assumption. For comparisons between conditions (NS and WS) and deadlift sets (1, 2,
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and 3), two way repeated measures analysis of variance was conducted with post-hoc
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testing. Dependent sample t-tests were used to compare Pre/Post HR, RPE-General, and
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RPE-M between conditions. Cohen’s d values were calculated to evaluate effect size
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(ES)and interpreted as follows: 0.2 = small, 0.5 = moderate, and 0.8 = large (6). A
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significance level of 5% was assumed. Data were analyzed with SPSS 17.0 for Windows.
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RESULTS
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Eleven subjects completed the study. The load from the WS 1RM test (180.0 ± 14.8
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kg) was statistically different (p < .001; ES= 1.3) than the load from the NS condition
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(151.0 ± 23.0 kg). The mean difference in 1RM between conditions (WS - NS) was 28.3 ±
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13.2 kg with a range of 10 kg to 50 kg.
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Table 1 exhibits the total number of repetitions performed in each set for each
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condition. A significant difference (F = 13.12; p < .001) was identified between the first and
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third sets in both conditions.
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Also, table 1 describes the kinematic values obtained from the comparison between
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conditions and between the three successive sets. A significant condition
set interaction
(F = 3.91, p = 0.03) was shown for peak speed (PSpeed). Follow-up analyses revealed a
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significant difference between sets for the NS condition (F = 3.6; p = 0.03) with a decrease
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in PSpeed from the 1st to 3rd set (p = 0.036). No between set differences were found for
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the WS condition. Paired samples t-tests showed significantly greater PSpeed during the
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NS condition for the 1st (p = 0.007) and 2nd (p = 0.043) sets when compared to WS, but no
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difference for the 3rd set (p=0.269). No significant interactions were identified for any of the
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other variables.
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For the between-condition (WS and NS) comparison, the average mean speed
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(ASpeed; ES= 0.8) and average PSpeed (ES= 0.9) were different in across sets, with
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higher NS values and large effects for both variables. Average mean force (AForce; ES=
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0.6)) and average peak force (PForce; ES= 0.7), were different across sets with medium
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effects and the highest values in the WS condition. The average duration was greater in
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the WS condition across all sets with a large effect (p < .02; ES= 0.8), while no differences
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were found for the average amplitude.
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Please, insert TABLE 1 here
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For the between-set comparison, APower in S1 was significantly greater than S2
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and S3 (p < .001; ES= 0.8) for both conditions with a large effect. ASpeed (p = .001; ES=
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1.1), PSpeed (p = .001; ES= 0.8), and average amplitude were significantly different
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between S1 and S3 (p = .01; ES= 1.8) with large effects.
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Figure 1 presents HR values prior to and immediately after each deadlift set for both
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the WS and NS conditions. All pre-set values were statistically lower than post-set (F =
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208.9; p = .04; ES = 2.3) with large effects. The only statistical difference for HR between
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conditions was after S3, with the WS condition producing higher values than the NS
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condition (F = 24.9; p = .04; 1.9) with a large effect.
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Please, Insert FIGURE 1 here
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Table 2 presents the general RPE values between conditions for each set and the
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muscle-specific RPE values between conditions. For RPE-G, values for WS were
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significantly greater than NS for both S1 and S2 (p < 0.02; ES = 0.6) with moderate
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effects, but not S3. For RPE-M, significant differences were noted in lumbar area and
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forearms. The values for the lumbar region were greater after the WS condition (p = 0.002;
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ES = 1.5), while the forearm values were greater under the NS condition (p = 0.03; ES =
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1.9), both with large effects.
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Please, insert TABLE 2 here
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DISCUSSION
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The present study aimed to evaluate the effects of lifting straps use on different
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kinematic variables during three successive sets of deadlift exercise. Differences were
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found in the concentric phase of the following variables: load, speed, force and duration.
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With regard to HR, a difference between conditions after the third set was shown, while for
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RPE-G, differences occurred following only the first and second sets.
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The deadlift primarily works the muscles of the lower limbs and back, and,
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secondarily, the hips, arms and shoulders (1). The current RPE-M results noted significant
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in the WS condition is likely related to increased cardiovascular demand as a result of the
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greater load applied compared with the NS condition (5). Additionally, removing the
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limitation of grip strength likely allowed the ability to generate more work through larger
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muscles groups, subsequently increasing cardiac output (1, 22).
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16% higher values for WS on the lumbar region and 45% higher values for NS on forearms region between conditions. The higher HR values following the third deadlift set
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In the current study, the maximum number of repetitions were not found to be
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significantly different between conditions (p=0.5). Conversely, Werneck (29) reported
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differences between conditions using the cable pulldown exercise at 75% of 1RM NS (27.3
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± 3.2 reps in WS condition vs 20.9 ± 2.4 reps NS, p < .01). This discrepancy may be
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explained by the fact that the present study utilized the condition-specific (NS or WS) 1RM
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values, and there was a large difference between conditions (180.0 ± 14.8 kg for WS and
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151.6 ± 23.0 kg for NS, p < .001), leading to greater total work for the WS condition. The
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inclusion of the 1RM prior to the deadlift training sessions could have had a confounding
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influence on deadlift performance which may be supported by differences in speed and
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duration, while the lack of difference between maximum number of repetitions does not
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support this assertion.
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When comparing the successive sets, a statistically significant difference was
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shown in the number of complete cycles (maximum number of repetitions) between the
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first and third set in both conditions (p < .001), which is supported by previous findings that
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noted declines in power, strength and speed with each repetition during power cleans (10).
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Forces (average and peak) were higher in the WS condition (p < .01), while speed was
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higher during NS (p < .03). This can be explained by the force-velocity relationship, which
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postulates that with low loads it is possible to generate higher speeds (10, 15).
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Conversely, as the load increases, the speed decreases progressively with a concomitant
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may be indicative of subjects realizing that grip strength is a limiting factor leading to a
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more rapid completion of the deadlift sets faster to avoid fatigue. Theses alterations in
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force and velocity parameters caused by the lifting straps may be considered during
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training prescription, because the parameters of strength and power are fundamental for
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increase in force production (26). Considering the self-selected cadence used in this protocol, it is hypothesized that the greater initial speed (and subsequent decline) with NS
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human athletic performance (4) and differences in acute neuromuscular responses to how
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lift-specific training volume is implemented may also play an important role in chronic
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neuromuscular adaptations (28). Neuromuscular fatigue is considered an important variable in the development of
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muscular strength and hypertrophic response (12) and may be elicited by an increased
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time under tension combined with heavy loads (28). Grip strength may be an important
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limiting factor during deadlift, leading to the premature interruption of the exercise and/or
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reducing training loads, which may compromise the stimuli imposed to the target muscles.
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Previous research has also shown that hand size and the use of bars with different
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thickness could affect deadlift’s performance (20). In order to overcome these limitations,
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many strategies have been used, such as, LS and an "alternate" or "inverted" grip (one
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hand supinated and the other pronated) (18). With the use of the former, the opposing
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rotational forces prevent the bar from rolling out of the hands of the lifter and, typically,
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increases the amount of weight that can be lifted. However, in competitive weightlifting, the
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inverted grip may cause excessive tension on the tendon of the biceps brachii of the
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supinated arm and generate undue hip rotation (1, 18), which would increase the risk of
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injuries and muscle imbalances. The double pronated grip used and the absence of chalk
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in our protocols may have resulted in the lower load of NS exercise and the subsequent
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differences in performance between conditions. Nonetheless, the use of lifting straps is
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workloads as demonstrated by both the 1RM testing and subsequent training data
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reported in the present study. The results of this study indicate that the use of lifting straps
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directly influences the absolute load of the deadlift exercise as well as its kinematic
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variables. With the use of lifting straps, it is possible to provide higher workloads to the
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considered suitable when the load is greater than or equal to 80% 1RM as it removes the limiting factor of grip strength during deadlift training and allows the utilization of greater
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target muscles than performing the exercise without lifting straps. The current findings
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demonstrate that the increased capacity to lift maximal loads with lifting straps allow for
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altered kinetics and kinematics, primarily increases in workload and time under tension,
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both of which are relevant variables for power acquisition and muscle hypertrophy. PRACTICAL APPLICATIONS
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Considering that speed was lower, and that force and duration were greater in the
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WS condition, coaches may choose to use lifting straps in order to focus on developing
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specific physical attributes during strength training. The greater absolute load in the WS
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condition resulted in altered kinematic variables during deadlift training. These alterations
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were likely due to the direct transfer of force to the bar via the lifting straps rather than the
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forearm and hands/fingers (23), thereby allowing the individual to have greater control of
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the movement. Thus, the positive effect of lifting straps on performance may be dependent
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on the targeted kinematic variables, as the increase in training load and force would be
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offset by decreased power during the deadlift movement. Finally, the authors suggest that
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future investigations compare other ergogenic techniques, such as the use of chalk and an
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alternated grip, to the results of those obtained lifting straps.
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ACKNOWLEDGMENTS
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The authors declare do not have professional relationships with companies or
manufacturers who will benefit from the results of the present study. None of the authors
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had any professional relationships with companies or manufacturers who will benefit from
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the results of the present study. The results of this study do not constitute endorsement by
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the
authors
or
the
National
Strength
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Conditioning
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24.Shimano, T, Kraemer, WJ, Spiering, BA, Volek, JS, Hatfield, DL, Silvestre, R, Vingrenm
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JL, Fragala, MS, Maresh, CM, Fleck, SJ, Newton, RU, Spreuwenberg, LPB, and
3
Hakkinen, K. Relationship Between the number of repetitions and selected percentages
4
of one repetition maximum in free weight exercises in trained and untrained men. J
5
Strength Cond Res 20: 819-823, 2006. 25.Siri, WE. Body composition from fluid space and density. In. Techniques for measuring
7
body composition. J, Brozek, and A, Hanschel Washington, DC: National Academy of
8
Science, 1961. (pp. 223-244).
TE
D
6
9
26.Swinton, PA, Stewart, AD, Keogh, JWL, Agouris, I, and Lloyd, R. Kinematic and kinetic
10
analysis of maximal velocity deadlifts performed with and without the inclusion of chain
11
resistance. J Strength Cond Res 25: 3163-74, 2011.
27.Swinton, PA, Stewart, A, Agouris, I, Keogh, JWL, and Lloyd, R. A biomechanical
13
analysis of straight and hexagonal barbell deadlifts using submaximal loads. J Strength
14
Cond Res 25: 2000-09, 2011.
17 18
C C
16
28.Tran, QT, Docherty, D, and Behm, D. The effects of varying time under tension and volume load on acute neuromuscular responses. Eur J Appl Physiol 98: 402-10, 2006. 29.Werneck, LA, Lattari, E, and Carvalho, E. The use of strap on pull down exercise with neutral footprint in high pulley. Braz J Exerc Phyisiol 10: 205-08, 2011.
A
15
EP
12
Copyright Ó Lippincott Williams & Wilkins. All rights reserved.
17
1 2
Figure Legends:
3
Figure 1: Pre and post heart rate values during WS and NS conditions.
5
* Statistically different from value with straps (p = .04). S1 = 1st set. S2 = 2nd set. S3 = 3rd set;
6
WS: with straps; NS: no straps.
A
C C
EP
TE
D
4
Copyright Ó Lippincott Williams & Wilkins. All rights reserved.
Table 1: Kinematic responses according to presence or absence of straps and comparison of three successive deadlifting sets. With Straps (WS) nd
rd
st
Condition
nd
rd
Sets
2 set
3 set
1 set
2 set
3 set
F
p
5±2
4±2
3±2
5±1
4±1
3±1
.3
.58
598 ± 140
528 ± 109
509 ± 115
669 ± 98
543 ± 179
455 ± 169
.1
Average Speed (m/s)
0.4±0.1
0.3±0.1
0.3±0.1
0.5±0.1
0.4±0.1
0.3±0.1
Peak Speed (m/s)
0.6±0.1
0.5±0.1
0.5±0.1
0.9±0.1
0.7±0.2
0.6±0.2
Average Force (N)
1822 ± 479
1725 ± 338
1835 ± 631
1321 ±156
1320 ± 83
1463 ± 428
11. 4 .007
.9
Peak Force (N)
2279 ± 573
2135 ± 438
2305 ± 730
1632 ± 161
1616 ± 107
1759 ± 469
14.9
.003
506 ± 79
458 ± 126
462 ± 89
583 ± 83
480 ± 187
430 ± 164
.5
1424 ± 262
1517 ± 631
1682 ± 634
1133 ± 141
1115 ± 246
1316 ± 422
12.6
Average Amplitude (mm)
Average Duration (ms)
EP
C C
Average Power (w)
A
Maximum # of repetitions
TE
1 set
D
st
No Straps (NS)
F
Interaction
p
F
P
13.1
