RKC School of Strength

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Felix Sempf

The Triple Extension Swing

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Felix Sempf Triple Extension Swing

For power sport athletes, jump and sprint performance are key factors for enhancing sports performance on the field. The ability to generate power has a significant effect on the athlete’s ability to perform in their respective sport (Komi, 2008). Besides mobility, and strength and conditioning work, an athletic training program should also include specific exercises for power. Since every athlete is different there is no “one-fits-all” exercise for power training. The main aspects to consider when planning a power training regimen are safety, practicability, and compliance of the athlete.

Power output in sprinting and jumping is higher if full extension is achieved at the ankle, knee and hip joint. For example, ankle plantarflexion accounts for more than 20% of vertical jump height and consequently is a key factor for maximizing power in jumping (Hubley & Wells 1983; Luthanen & Komi, 1983). Likewise, McKinley & Pedotti (1992) also showed a higher degree of plantarflexion in jump-trained individuals compared to novices. Based on these findings, a power exercise for athletes in most team sports should mimic the triple extension for best transfer effects.

The regular kettlebell swing is a relatively simple power exercise that focuses on achieving full hip and knee joint extension in a dynamic fashion. Therefore, it only targets two of the three major joints that contribute to power generation in jumping motions (Hubley & Wells 1983; Luthanen & Komi, 1983). Other studies have confirmed that jump height and power can be improved by implementing kettlebell swings in the training program (Lake & Lauder, 2012; Otto et al., 2012; Mannocchia et al., 2013; Jay et al. 2012). Despite these benefits, the regular swing does not include ankle plantarflexion and may therefore (if used excessively) negatively affect jumping mechanics by neglecting a powerful contributor. A simple solution for this is the so-called Triple Extension Swing, which also includes ankle plantarflexion.

If your regular kettlebell swing technique is solid and you are looking to improve your vertical jump, try performing the following swing variation: Move up on your toes after the extension of the hip and knee has been initiated and finish the movement with all three joints extended as pictured below. You will immediately see and feel a higher float of the kettlebell. Start with light weights, safety first.

Warning:
This advanced swing variation is not be appropriate for beginner or less experienced intermediate levels. Only attempt the triple extension swing after demonstrating proficiency with the standard RKC swing. Moving up to the toes with the triple extension swing carries the risks of losing control of the kettlebell, being pulled forward, not fully engaging the glutes, overall loss of stability, incomplete grounding, and not safely loading on the backswing.

 

Literature

Hubley & Wells (1983). A work-energy approach to determine individual joint contributions to vertical jump performance. European journal of applied physiology and occupational physiology. 50 (2), 247–254.

Jay et al. (2012). Effects of kettlebell training on postural coordination and jump performance: a randomized controlled trial. J Strength Cond Res. 2013 May; 27(5):1202-9.

Komi (2008). Strength and Power in Sport. Volume III of the encyclopedia of sports medicine.

Lake & Lauder (2012). Kettlebell swing training improves maximal and explosive strength. J Strength Cond Res. 2012 Aug; 26(8):2228-33.

Luhtanen & Komi (1978). Segmental contribution to forces in vertical jump. European journal of applied physiology and occupational physiology. 38 (3), 181–188.

Manocchia et al. (2013). Transference of kettlebell training to strength, power, and endurance. J Strength Cond Res. 2013 Feb; 27(2):477-84.

McKinley & Pedotti (1992). Motor strategies in landing from a jump: the role of skill in task execution. Experimental Brain Research. 90 (2), 427–440.

Otto et al. (2012). Effects of weightlifting vs. kettlebell training on vertical jump, strength, and body composition. J Strength Cond Res. 2012 May; 26(5):1199-202.

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Felix Sempf, PhD Candidate, M.A. Sportscience, RKC, trains and instructs at the FIZ in Göttingen, Germany. He can be contacted by email at: felix.sempf@sport.uni-goettingen.de and his website: http://www.kettlebellperformance.de

Squat Controversies

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RKC Instructor Felix Sempf

Although many good articles have been written about squatting, coaches are still frequently confronted with “do not go below parallel or 90°”, “you shouldn’t bring your knees past your toes”, or “squats are bad for your back”. Given these controversies and the fact that the squat is one of the fundamental exercises for RKC kettlebell training, the purpose of this article is to review the most important aspects of this exercise.

The squat is versatile—it has been shown that a 1RM squat is highly correlated to jump and sprint performance (Wisløff et al., 2004) and it can improve knee stability through a development of tighter joint capsules (Chandler et al., 1989). It is particularly useful for training athletes, but can also help improve strength and functionality in non-athletic populations. Squats improve the function of the gluteal muscles which will prevent injury or decrease back pain. Squats can also help everyone with daily tasks such as lifting items from the ground, or climbing stairs. It is important to note that research has not been able to establish a relationship between (deep) squatting and a greater risk of knee and back injuries, given that the exercise is performed with proper technique (Meyers, 1971; Panariello et al., 1994; Steiner et al., 1986; Hartmann & Wirth, 2014).

Squat Depth

Li et al. (2004) showed that the greatest stress on the posterior cruciate ligament during squatting occurs at around 90° of knee flexion. The authors further stated that deep squats help to constrain the knee joint and significantly reduce anterior and posterior tibial translation as well as tibial rotation compared to smaller flexion angles, thereby reducing the stress on the cruciate ligaments. Li et al. (2004) also found “the tolerance to load is enhanced in the deepest portion of the squat with a protective effect conferred to ligamentous structures”. This is in accordance with other researchers (Kanamori et al., 2000; Li et al. 1999; Sakane et al. 1997) who observed reduced stress on the crucial ligaments for knee flexion at angles greater than 90˚.

Caterisano, et al. (2002) looked at the relationship between squat depth and activation of the gluteus maximus and found no difference between partial and parallel squats. However, they reported significant increases in gluteus maximus activity during the deep squat. Given the high incidence of hip osteoarthritis in former elite athletes, and the correlation with reduced passive ROM in hip-flexion (L’Hermette et al., 2004), deep squats may be a useful tool in the prevention of hip-osteoarthritis by improving hip flexion. In summary, there is evidence to suggest that squatting below 90° with proper technique reduces stress on passive structures such as the cruciate ligaments and can have a protective effect in regard to hip and lower back health.

(Source: http://www.aaronswansonpt.com)
(Source: http://www.aaronswansonpt.com)

Squats and Injuries

Tibiofemoral compressive peak occurs at 130° of knee flexion and the menisci and articular cartilage will bear significant amounts of stress (Nisell & Ekholm, 1986). As peak patellofemoral compressive forces occur at or near maximum knee flexion, those with patellofemoral disorders or acute injured menisci should avoid high degrees of knee flexion (Sakane et al., 1997; Escamilla et al., 2001). With regard to the cruciate ligaments, Li et al. (2004) concluded, “For those with existing injury or previous reconstruction of the PCL, it is best to restrict flexion to 50° to 60° so that posterior shear is minimized”. “However, there is little evidence to show a cause-effect relationship implicating an increased squat depth with injury to these structures in healthy subjects” (Schoenfeld, 2010).

Knees Over Toes

List et al. (2013) showed that restricting the amount of ankle motion (knees not allowed over toes) led to a smaller ROM at the knee, higher changes in the curvature of the thoracic spine, and higher segmental motions within the trunk. Consequently, the stress placed on the back increased when ankle motion was restricted. This is in agreement with other research, “Although restricting forward movement of the knees may minimize stress on the knees, it is likely that forces are inappropriately transferred to the hips and low-back region. Thus, appropriate joint loading during this exercise may require the knees to move slightly past the toes” (Fry et al., 2003). Escamilla (2001) came to the conclusion that significant strength and sagittal plane mobility is required at the ankle for proper squat performance.

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Felix Sempf, RKC, PhD Candidate, M.A. Sportscience, trains and instructs at the FIZ in Göttingen, Germany. He can be contacted by email at: felix.sempf@sport.uni-goettingen.de and his website: kettlebellperformance.de

Why We Grunt

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RKC Instructor Felix Sempf

When entering a room where RKC kettlebell training is in progress, one quickly notices the characteristic way people breathe while performing the exercises. Although this “grunting” may sound unfamiliar and disconcerting at first, breathing in sharply through the nose and breathing out slowly while gritting the teeth should become a part of everyone’s training routine.

In order to understand why we use the “biomechanical breathing” method for improved performance and safety, we first need to talk about the anatomy of the trunk and core. Today, most researchers agree that the lumbar region is an area that relies heavily on stability and where excessive range of motion should be avoided (Battie et al, 1990; Biering-Sorenson, 1984; Cuoto, 1995; Saal & Saal, 1989; McGill, 2010). In the original sense, the widely-used term “core stability” describes “the ability of the lumbopelvic hip complex to prevent buckling and to return to equilibrium after perturbation” (Wilson et al., 2005). In other words, core stability is the ability to produce and maintain a neutral lumbar spine (Gottlob, 2001). According to the National Institute for Occupational Safety and Health, keeping a neutral spine is recommended when lifting something heavy off the ground or being under load…

Several muscles, such as the latissimus dorsi, erector spinae, quadratus lumborum, multifidii, and obliques—but also the glutes and adductors contribute to the stability of the core (Filey, 2007). More importantly, most of these muscles are connected via the thoracolumbar fascia, thereby forming a natural weightlifting belt around the lumbar spine. In conjunction with the diaphragm and the muscles of the pelvic floor, they help to maintain or build core stability by forming a shell around the lumbar region. Contracting the core and hip muscles leads to muscular stiffness and therefore the flexibility of the shell decreases and becomes more rigid. Filling the rigid shell with air by sharply inhaling through the nose will increase the so-called intra-abdominal pressure, leading to greater compression of the spine and consequently higher intervertebral stiffness (increased lumbar spine stability).

diagram of human breathing

A sharp inhalation has the advantage of automatically contracting the core muscles, which does not happen during slow breathing. The same effect is observed when exhaling while gritting one’s teeth—sufficient intra-abdominal pressure is maintained because more air will remain in the respiratory pathways while air flow is constricted. Continuous breathing allows continuous spine stability and is therefore preferable to the “valsalva maneuver”, when performing a task for more than one repetition. In support of this theory, Stuart McGill (2007) reported that using this breathing technique—known as “kime” in martial arts—when performing swings lead to a significantly greater contraction of the obliques. Thus, safety and performance can be enhanced by just breathing the right way.

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Felix Sempf M.A. Sportscience, RKC, FMS, PM trains and instructs at the FIZ in Göttingen, Germany. He can be contacted by email at: felix.sempf@sport.uni-goettingen.de and his website: http://www.kettlebellperformance.de