The most common type of supportive equipment utilized in powerlifting is the squat suit (SS). The SS has the same fit and relative design of a singlet used in weightlifting, composed of various materials that stretch and then contract during the lift to possibly aid in increasing force, power and velocity. However, no previous investigation has examined the effect of a SS on squat performance.  Thus, the purpose of this investigation was to investigate various kinetic and kinematic variables associated with squats with and without supportive equipment (i.e. SS)

NC DOCKS at Appalachian State University

Skinner, Jared Wayne

English

The University of North Carolina at Greensboro

KINETIC' AND KINEMATIC ANALYSIS O F  THE SQUAT WITH 4 N D  L!'ITf-IOLTT SUPPORTIVE EQUIPMENT '4 Thesis by JARED WAYNE SKINNER Submitted to the Graduate School Appalachian State University In partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Ma! 201 1 Department of Health. Leisure. and Exercise Science KINECTIC AND KINEMATIC ANALYSIS O F  THE SQUAT WITH AND WITHOUT SUPPORTIVE EQUIPMENT A Thesis by JARED b'AYNE SKINNER Ma) 201 1 APPROVED BY: Jeffrey M. McBride Chairperson. Thesis Committee N. Travis Triplett Member. Thesis Committee Kevin Zwetsloot Member. Thesis Committee P a d  L. Gaskill Chairperson. Department of Health. Leisure. and Escrcisc Science Edelnia D. Huntley Dean. Research and Graduate and Studies Copyright by Jared Wayne Skinner 201 1 All Rights Resened ABSTRACT KINETIC AND KINEMATIC ANALYSIS OF THE SQUAT WITH AND WITHOLIT SUPPORTIVE EQUIPMEYT Jared Wagne Skinner B.S.. Appalachian State University M A .  Appalachian State Uni~ers i t )  Chairperson: Jeffrey M. McBride The most common type of supportive equipment ~~ t i l i zed  in ponerlifting is the squat suit (SS). The SS has the same fit and relative design of a singlet used in \veightlifting. composed of various materials that stretch and then contract d ~ ~ r i n g  the lift to possibly aid in increasing force. power and \.elocity. I-lowever. no prwious investigation has examined the effect of a SS on squat performance. T ~ L I S .  the purpose of this inwstigation rras to iwestigate \.arious kinetic and hineniatic \.ariables associated with squats with and \\-ithout supportive equipment (i.e. SS). Participants \Yere eight elite or professional le\el male potverlifters (height = 178.59 + 3.5 cni: bod) mass = 106.8 + 30.4 kg: age = 25 + 2.2 yrs: mean IRM =197.7+53kg) \vith a minimum of f o ~ ~ r  years of resistance training and po\verlifting experience and displayed competent technique in the squat utilizing a SS. Subjects participated in three testing sessions. wit11 the first session involving a one repetition masin~utii squat ( IRM)  without a SS. Session t ~ v o  and three involved a testing session conlpleting two trials in the squat at three intensities (80. 90 and 100% of IRM) either ivith (N'SS) or ~.i t l iout  he squat suit (A'SS). The session and order of the intensities Lvere all randomized. Subjects were instructed not to perform lotver body exercise 72 hours prior to each testing session and each session was separated by 1 week. Force-time. velocit)--time and potver-time graphs and horizontal and \.ertical displacement of the barbell during each lift were generated from data collected from a force plate under the lifter's feet and hvo linear position transducers attached to the barbell. Peak force. velocit] and power \{.ere calculated for both the eccentric and concentric phase of the lift. Vertical and horizontal displacenient \\ere utilized to graph the bar path for both conditions. Statistical significance was chosen at p 5 0.05. KESUI.TS: There Lvere no significant differences in peak concentric force during WSS in comparison to NSS at all intensities (80%. 90% and 100% of I RM). Ho\vever. peak eccentric force was significantly higher during WSS at 100% of IRM (NSS = 32221427N. U'SS = 3 3 7 5 ~ 5 5 9 N ) .  Peak concentric \,elocity \<.as significantly higher during b 'SS in comparison to KSS all intensities. There Lvas no significant difference in peak eccentric velocity and peak eccentric power bet\veen the WSS and NSS. Ho\i-ever. peak concentric power M-as significantly higher during M'SS at 80% of I R M  (NSS=I441+JlOW: SS=l795+513W) and 9O%of 1Rhl (NSS=I380+382W: SS=1647+525WJ). Significant differences in vertical bar path displacenient were obsewed bet~veen WSS and NSS at 80%. 90% and 10096 of I RM. During NSS there ivas significantly greater vertical displacement. In conclusion. the current inyestigation has V demonstrated significantly different kinetic and kinematic characteristics between squats tvitli and uithout the SS. The SS altered bar displacement during the lift and improved peak eccentric force. peak concentric velocity and peak concentric power that would ultimately aid in enhancing squat performance. This thesis \\-as completed through the support of  the Office of  Student Research Grant. the Graduate Senate Association Senate Research Grant. and Inzer Ad\.ance Designs. I \vould like to thank my committee members. Jeffrey McBride. a mentor and friend over tlie many years I have been here. You lia\,e pushed me to become a better researclier and student. YOLI helped inspire me to continue my education in Biomechanics. for which I \\.ill always be gratefid. I \<auld like to thank my friend Travis 'I'riplett. the strongest women I have ever met. You seemed to always h a w  time for advising me in school and life. I u.ould also thank Kevin Z\vetsloot: \vitlmur your tutelage this thesis \vould not be possible. I \vould like to give a special thanks to all those \vho helped in tlie ne~rrom~~scular  lab on this prqject. mainly Kim Fairbrother. James Snyder and Justin Blatnik. I would like to thank Megan Bryanton for her l o x  and support and helping rile tlirough this year. Lastly. I ~ o u l d  like to thank my family: Mom. Dad. Kyla and Ma\vma\\. xhose  support and lo1.e has and \ \ i l l  continue to glide me through life. TABLE O F  CONTENTS PAGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  ABSTRACT.. . i \ ,  LIST OF TABLES LIST OF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  FIGURES.. . . . . . . . . .  . xi METHODS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  Subject..  . . . . . . . . .  .......subject............................. 5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  Study design. .  5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  Maximal Strength Testing.. .6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  Squat Perfortilance Protocol.. 7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  Kinetic and Kinematic Data Collection and Analysis 7 Axerage Curve Analqses.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  Sta t~s t~ca l  Analyses.. .8  RESULTS . . . . . . . . . . .  . . . . . . . . . . . . . . . . . . . . . . .  9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  DISCIJSSION.. I0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  PRACTICAL APPLICA~I'IONS.. I 3  viii LIST OF TABLES Table 1:  Subject Anthropomet~ics and Strength Measurements.. . . . . . . . . . . . .  . , . ,  . . . . . , . , . . . . . .  17 . , . Table 2 :  I'eak Values (WSS and hSS)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  I8 INI'KODUCTION The squat movement requires both lo~ver  body and trunk strength and is used in training programs of \.arious t!pes of athletes [ I ] .  It also has been identified as an integral component of competitive Weightlifting and I'otverlifting [2]. The sport of po\verlifting. in particular. o f e n  involves the use of supporti\:e equipment. the most conimon being a squat suit (SS) .  The SS has the same tit and design of a singlet ~ ~ s e d  i n  neightlifting. composed of various materials that stretch and constrict during tlie movement to possibly aid in lifting more \veight. However. no scientific data esists to substantiate this claim. Theoretically. the SS material stretches and stores elastic energy during the eccentric phase of the lift. The elastic energy ma!. then be released during the concentric phase enhancing the ability to lift heavier weight \.ia increasing force. velocity and power. In addition. due to the constrictive nature of tlie SS it is possible that the kinematics of the lift may be altered as retlected in \.arying bar paths. Most acti\ities of dail! living require the coordinated contraction of sewral ml~scle groups at once. and squatti~ig (a  multi-,ioint movement) is one of the fe\\ strength training esercises that is able to effectiwl) recruit multiple niuscle groups in a single movement [3], The lifter stands in an erect position \vith the feet ~ ~ s u a l l y  placed shoulder-width apart. At the start of  the lift the lifter \\- i l l  flex at the hip. knee and ankle \vhile keeping his or her trunk erect. beginning the eccentric portion of the lift where the bar and the lifter \ \ i l l  descend to \\-here the top of the thigh becomes parallel \\-it11 the floor. At this point the exercise becomes increasingly difficult due to the different lever systems involved in the mo\~ement pattern [ I ] .  The knee and hips are considered third class levers. meaning that the resistance arm is greater than the moment arm and there is limited mechanical ad\.antage during different phases of the nio\:ement [4]. When the desired depth is achieved the lifter will reverse the direction and begin ascending uplvard to their initial position. Mitetello et al,  e ra~nined tlie kinematic variables b e t w c n  collegiate po\verlifters. high school po~verlifters and novice powerlifters and determined variation in concentric acceleration rates between the three groups during \.arious points in the lift. Specifically, the data indicated that the more experienced powerlifters. who lifted more weight. achieved higher velocities in the concentric phase when conlpared to the novice and high school lifters [ I ] .  The data suggest that if supportive equipment. such as the SS, c o ~ ~ l d  increase concentric velocity then this may increase tlie amount of weight lifted as well. While no in\.estigations have looked specifically at the SS some studies have examined the effect of compression garments. such as shorts. on jumping performance. One investigation determined that with the use of a custom fitted compression garment increased power in the \.ertical jump. In addition. skin ten~perature increased at a faster rate during tlie warm-up protocol and increased flexion a ~ i d  torque rates during sprints and resulted in a reduction of impact forces by 27% in comparison to traditional athletic wear [j]. Another study suggests performance e~ihancement \\hen wearing compression garments during simulated sporting events such as netball [ 6 ] .  While the SS and compression garments are not tlie same they both consist of some similar characteristics allowing for speculation as to the benefit of a SS on squat performance. Considering the complexity of the squat and the number of muscles and joints it encompasses. understanding the biolnechanics of the 

Kinetic and Kinematic Analysis of the Squat with and Without Supportive Equipment

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Kinetic and Kinematic Analysis of the Squat with and Without Supportive Equipment

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