Barbell squats (back) have been one of the most popular exercises. It’s popularity mainly related to increasing the muscular strength in the lower body. It is also used for conditioning and for rehabilitation of injuries.But it is also a common phenomenon where athletes get injured (1) directly as a result of squats, especially in the knees and the lower back. (2, 3, 4, 5).
There have been researches where skilled and unskilled powerlifters have been studied upon for biomechanical differences on barbell back squat analyzed. (6, 7).
There also have been studies where the stress levels created upon the lower back and knees (8, 9, 10, 11) have been looked into. Moreover, excessive forward trunk lean has been frequently been identified as a common error in technique while performing the squat.
Weighlifters are recommended to use weightlifting shoes for their competition and their training. Many of these shoes are designed with hard soles with slight elevation. While there is no fixed height that has been prescribed for this elevation, the heels are usually elevated by 2.5cms which causes a change in the angle near the ankles in a squat which, as a result causes a change in the angle of the trunk. It is believed that the weightlifting shoes help in maintaining a more upright posture which further helps in reducing the stress in the lumbar region.
In this paper we will discuss about the study conducted by Kimitake Sato , Dave Fortenbaugh , and David Hydock which determined the differences in selected squat kinematics between weighlifting shoes and running shoes during the barbell back squat. This study also identified whether weighlifting shoes are biomechanically beneficial without compromising with the proper squat technique. It was earlier concluded that squatting with weightlifting shoes reduces the stress on the lower back because wearing weighlifting shoes would lead to less posterior displacement of the hips.
25 volunteers were recruited for this study out of which 20 were male and 5 were female. The volunteers had been participating in resistance training in resistance training which included back squats for an average of 5-7 years under qualified supervisors. All the volunteers were free from injuries for at least 3 months before the study was conducted. This part of the method was important because they had to test the difference in stress created on the lower back while wearing the weightlifting shoes and while wearing running shoes. The 1RM was also checked one month before the test. In order to achieve accurate comparisons, all lifts were performed at light loads (at 60% of 1RM)
[ There were multiple factors considered in determining the method to conduct this study. They have been elaborated in the studya attached. In my opinion, the researchers have covered every possible loophole there could have been in such studies that needed to be conducted]
The aim of this study was to identify the squat kinematic differences between weightlifting shoes and running shoes and also to identify the benefits of wearing weightlifting shoes. No scientific studies have investigated biomechanical characteristics of the barbell back squat when using 2 types of footwear to compare the kinematic data. If weightlifting shoes contribute to achieving optimal squat performance and help reduce the risk of injuries based on the kinematic data, this information should be acknowledged. The first hypothesis supported was that the weightlifting shoes could create a higher foot segment angle because of their non- compressible and raised heel structure when compared with the running shoes.
Therefore, wearing the WL shoes may result in engaging greater muscle activity in the knee extensor muscles when compared with wearing running shoes. Having said that, a greater degree of foot segment angle (to some extent) that is created by wearing weighhtlifting shoes may be beneficial for those who are aiming to increase muscular strength in the knee extensors.
This study also supported the second hypothesis that the back squat with the WL shoe would cause lesser trunk lean displacement when compared with that of the running shoe condition. However, there will always be some anterior bar displacement along with some posterior hip displacement during the back squat, which creates trunk lean. The goal, at this point, is to minimize these movements to reduce the amount of trunk lean. As mentioned in the Introduction, a greater degree of the trunk lean creates increased shear force in the low back area. This study demonstrated that the WL shoe condition reduced the amount of forward trunk lean, which ultimately would lead to reducing the risk of low back injury.
The present study’s findings may help beginners and low-skilled lifters prevent excessive forward lean by wearing WL shoes.
This study also aimed to investigate whether the WL shoes allow lifters to bring the thigh at least parallel to the floor position more easily.
This third hypothesis was not supported. During the collection of the data, the subjects were simply instructed to perform the back squat as they normally would. With 0 set as parallel to the floor, the results showed that the thigh segment reached 20 for both footwear conditions. This outcome indicates that the WL shoes are not necessarily a contributor in allowing lifters to more easily attain the thigh parallel to the floor position during the back squat.
However, further investigations are needed to assess other biomechanical variables, such as joint kinetics, and especially those in the knee joint and low back area should be considered to measure actual joint stress as a result of variations in footwear.
Weightlifting shoes are believed to be an effective footwear choice of weightlifters. This study demonstrated that weightlifting shoes change the squat technique by minimizing the forward trunk lean displacement and increasing the foot segment angle (placing the ankle in a plantar-flexed position). Athletes may find the findings of the current study useful for their practices. Weightlifting shoes contributed to minimize trunk lean, meaning that individuals who have a history of low back injury or want to reduce stress in the back area may likely benefit from wearing weightlifting shoes. Footwear with raised heel can be an alternative to strengthening the knee extensor muscles without compromising the squat technique. The results of this study can also be applied to help beginner lifters to perform the back squat appropriately by using WL shoes. It is important for young individuals who start participating in resistance training to learn the correct squat technique. Weightlifting shoes may be just a supplemental tool to teach young lifters to keep an upright posture without compromising on other essential features.
1] Chandler, TJ and Stone, MH. The squat exercise in athletic conditioning: A position statement and review of literature. Strength Cond J 13: 51–60, 1991.
2] Escamilla, RF, Fleisig, GS, Lowry, TM, Barrentine, SW, and Andrews, JR. A three-dimensional biomechanical analysis of the squat during varying stance widths. Med Sci Sports Exerc 33: 984–998, 2001.
3] Flanagan, SP and Salem, GJ. Bilateral differences in the net joint torques during the squat exercises. J Strength and Cond Res 21: 1220–1226, 2007.
4] Fry, AC, Smith, JC, and Schilling, BK. Effect of knee position on hip and knee torques during the barbell squat. J Strength Cond Res 17: 629–633, 2003.
5] Nisell, R and Ekholm, J. Joint load during the parallel squat in powerlifting and for analysis of in vivo bilateral quadriceps tendon rupture. Scand J Sports Sci 8: 63–70, 1986.
6] McLaughlin, TM, Dillman, CJ, and Lardner, TJ. A kinematic model of performance in the parallel squat by champion powerlifters. Med Sci Sports Exerc 9: 128–133, 1977.
7] McLaughlin, TM, Lardner, TJ, and Dillman, CJ. Kinetics of the parallel squat. Res Q 49: 175–189, 1978.
8] Escamilla, RF, Fleisig, GS, Lowry, TM, Barrentine, SW, and Andrews, JR. A three-dimensional biomechanical analysis of the squat during varying stance widths. Med Sci Sports Exerc 33: 984–998, 2001.
9] Flanagan, SP and Salem, GJ. Bilateral differences in the net joint torques during the squat exercises. J Strength and Cond Res 21: 1220–1226, 2007.
10] Fry, AC, Smith, JC, and Schilling, BK. Effect of knee position on hip and knee torques during the barbell squat. J Strength Cond Res 17: 629–633, 2003.
11] Nisell, R and Ekholm, J. Joint load during the parallel squat in powerlifting and for analysis of in vivo bilateral quadriceps tendon rupture. Scand J Sports Sci 8: 63–70, 1986.
*Research that formed the subject matter of this paper: Kinematic Changes Using Weightlifting Shoes on Barbell Back Squat.
*Studies conducted by: Sato, Kimitake1; Fortenbaugh, Dave2; Hydock, David S3
*Published in: Journal of Strength & Conditioning Research: January 2012 – Volume 26 – Issue 1 – pp 28-33 doi: 10.1519/JSC.0b013e318218dd64
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