Salam Satu Malaysia,
Berikut adalah komen dan pandangan terhadap artikel sebelum ini. Komen ini telah dikemukakan oleh En. Jeffrey Low (Pensyarah UPSI). Di sini beliau telah membandingkan cara melakukan senaman tersebut dan juga sedikit latar belakang tentang latihan otot teras.
Seterusnya, kita guru PJK sedang sibuk mengendalikan ujian SEGAK di sekolah masing-masing. Marilah kita mula satu perbincangan tentang Ujian yang digunakan dan bagaimana kita dapat memperbaiki perlaksanaan Ujian SEGAK ini.
Latihan otot teras (Core stability training). Does it really improve performance?
The purpose of this contribution is to supplement the article with evidence based practice of core stability training (see Willardson, 2007, for a review). Strength and conditioning trainers and fitness gurus have been propagating the benefits of core stability training (CST) as part of the conditioning phase. They recommended that these activities provide a foundation for greater force production from the arms and legs which understandably the main extremities of the human anatomy in sports related movements. Core stability is a dynamic concept that continually changes according to the demands of postural position and external loads on the athlete’s body. New equipments were introduced and traditional static activities were given a new breath. The popularity of this exercise programme mushroomed probably because of the novelties (e.g. balancing on oversized beach balls like some circus acts) rather than empirical evidence. The question now does core stability training really improve performance? Whilst there has been anecdotal evidence on the benefits of using Swiss ball, valid scientific investigations are needed to confirm its potential.
Whilst we wait with bated breath, let’s find out how the oversized beach ball got its name? Swiss ball was named from the country which started using it for physical rehabilitation exercise back in the 1960s. Patients with low back injuries were prescribed such exercises to strengthen their abdominal musculature (McGill, 2001).
Behm, Anderson and Curnew (2002) examined the effectiveness of exercising on this ball, which creates an unstable surface against stable surface (e.g. floor or bench). The side bridge exercise activated greatest amount of core muscle activation, (see http://www.youtube.com/watch?v=NEo2QUfkbsg for a description of the exercise) whilst the shoulder press yielded no differences. However, both the shoulder press and chest press either using the bench or the Swiss ball activated significant core muscles. The study concluded that prescription of core stability exercises irrespective of strengthening or enduring the core musculature for healthy athletes or rehabilitation should be done with a destabilising component (i.e. either on a Swiss ball or moving limbs outside the base of support). Similar study compared the maximal voluntary contraction of the rectus abdominis during curl up exercise on the Swiss ball and on the floor. Exercise on the blasted ball resulted in 50% more maximal contraction than exercising on the floor. The researchers concluded that the unstable condition exerted higher demands on the motor system, thus eliciting more stimuli on the muscle. This increased neural activity is thought to improve the strength and endurance of the effected muscle (Vera-Garcia et al., 2000).
Should every gym now be littered with Swiss balls of various colours and sizes, purchased with money gained from disposing the free weights to scrap metal dealers (no pun intended). Although there is empirical data to prove the effectiveness of the CST, few sports’ movements simulate the conditions found exercising on the Swiss ball. The traditional exercise regime with free weights on stable surface still benefits strength and endurance of sport specific movements. Athletes who performed traditional weight training exercise would have improved their core stability provided the activities are conducted with a stable spine. For example, healthy athletes who performed deadlift, squat, power clean are likely to be reaping the benefits of CST without using the Swiss ball. Moreover, studies found using these weights on the Swiss ball allows parallel development of core stability and force production of the limbs (Mc Curdy et al., 2005), thus killing two birds with one stone.
Does CST improve balance? Balance exercises (static and dynamic) are thought to activate the core muscles as sudden loss of balance during a voluntary movement could be physically explained as movement of the centre of gravity (lumbar spine region) outside the base of support. To return the centre of gravity to inside the base of support, postural adjustments need to be made. As such it is thought that core muscles are activated to stabilise the region. Many if not most of all sport skills are performed off balance, greater core stability provides a solid base for force production from the extremities (Cosio-Lima et al., 2003). However, balance is sport and skill specific as study on ice hockey players found negative correlation between skate speed and balance. The ice hockey players were assessed their speed in skating as dynamic balance is thought to be essential for the skill. However, the players performed poorly on the balancing board test, lending to the conclusion that dynamic balance differs from static balance. Swiss ball may not be beneficial to train balance as the results of the study found high level of static balance did not transfer to dynamic balance (Behm et al., 2005).
The empirical evidence of CST presented above breathes a sigh of relief for strength and conditioning trainers and instructors. As we progress in developing athletes with sound training programmes through scientific research (now we can be assured that our quest in producing future athletes are underpinned by scientific principles). Since most if not all sport skills are performed in unstable positions which increase the probability of injuries, CST should be an integral part of the training programme. However, care should be taken by coaches / trainers to be well versed with the protocols and prescribing CST should adhere to the objectives of the conditioning programme (e.g. strength and power during pre season and muscular endurance for post season mesocycles). Future recommendations should now focus on creating new activities for CST that are sports specific.
References
Behm, D.G., Anderson, K. & Curnew, R.S. (2002). Muscle force and activation under stable and unstable conditions. Journal of Strength and Conditioning Research. 16, 416-422.
McCurdy, K.W., Langford, G.A., Doscher, M.W., Wiley, L.P. & Mallard, K.G.(2005). The effects of short-term unilateral and bilateral lower-body resistance training on measures of strength and power. Journal of Strength and Conditioning Research, 19, 9-15.
McGill, S.M. (2001) Low back stability: From formal description to issues for performance and rehabilitation. Exercise Sport Science Review, 29, 26-31.
Vera-Gracia, F.J., Grenier, S.G. & McGill, S.M.(2000). Abdominal muscle response during curl-ups on both stable and labile surfaces. Physical Therapy, 80, 564-569.
Willardson, J. M. (2007). Core stability training: Applications to sports conditioning programs. Journal of Strength and Conditioning Research, 21, 979-985
