Moffit M, Lieu DK, University of California, Berkeley, 1995, http://www.me.berkeley.edu/faculty/lieu/Martial_Arts_Headgear.pdf
1993 study - rates of cerebral concussion per minute of exposure, tkd 7.9x higher than football. Data skewed due to under-reporting of injuries in martial arts.
Strains resulting from pressure gradients during acceleration are set up when head is struck - Dura mater tissue damage, brain stem, craniospinal junction - motion in any direction, linear, rotational can cause injuries. If had previous concussion, higher risk of more permanent brain damage and also if receive repeated mild head trauma as a child participating in sport.
If critical pressure increases - enlarged vascular system, edema, excessive tissue fluid accumulation.
Head injury criteria - acceleration vs impact duration of WSTC
a(t) is acceleration in 'g's measured at the center of the mass of the head, t1 & t2 initial and final times in seconds between which the HIC is evaluated as a maximum. 1000 is the maximum permissible level. HIC time interval must be less than 15 ms to pose concussion hazard even if HIC over 1000.
In Karate (Schwartz 1986), punches to side of head produced higher accelerations than kicks to front or side of head, punches to front of head, lowest acceleration.
Lowering peak force better measure than local acceleration.
Study tested through:
- modelling speed and energy content of a basic tkd kick
- modelling important body segment parameters representing a body being kicked
- modelling important body segment parameters for a body falling backwards
- developing test speed to measure kick speed and head acceleration profiles
Serena & Lieu 1991 - athletes can deliver kicks up to 16 m/s with 200 joules energy to the chest. 25% decrease in velocity for kicks to the head.
- frontal & occipital - 9.4 m/s and temporal 10.1 m/s = HIC 1000 bare head
- frontal 10.6 m/s, temporal 11.6 m/s, 10.4 occipital = HIC 1000 poorest performing headgear
- 12.0 m/s frontal, 12.6 temporal, 11.1 occipital = HIC 1000 general thicker headgear
http://bjsm.bmj.com/content/38/2/143.full,P Douris, A Chinan, M Gomez, A Aw, D Steffens, S Weiss,,Br J Sports Med 2004;38:143-147 doi:10.1136/bjsm.2002.001768
18 volunteers aged 40-60: 9 sedentary, 9 martial art practitioners (7 men, 2 women) from a SBD school, community members, and members of the New York Institute of Technology. Tested between 9am-12pm - body composition (calipers), balance (timed limb stance), strength (handgrip dynamometer, isokinetic machines), endurance (situps and pushups), flexibility (sit and reach box), Vo2Max/Cardio (treadmill)
"The primary finding of this study was that middle aged adults whose only exercise programme is SBD, who have participated at least twice a week for at least three years display greater cardiorespiratory fitness, muscle strength, muscle endurance, flexibility, and balance, and less body fat than matched healthy sedentary subjects
Our study has shown that the long term practice of SBD may benefit cardiorespiratory function, muscle strength, muscle endurance, flexibility, balance, and body composition in middle aged practitioners. Similar physiological benefits have been documented in young2 and older martial artists.1,3,5–7,9,11 The results provide evidence that SBD training is an effective intervention that may reduce or prevent a number of functional and physiological declines associated with normal aging. In addition, the exercise characteristics of SBD fulfil the criteria proposed by the ACSM for developing and maintaining optimal body composition, flexibility, balance, and cardiorespiratory and muscular fitness in healthy adults15,16 Future studies may take a longitudinal approach rather than the cross sectional approach. Length of training should also be controlled in order to document the physiological changes during specific time periods. This study should be replicated with younger and older practitioners with larger samples"
Capoeira - range of inverted exercises (e.g. headstands, handstands), but not static with head down like gymnast instead - chin tucked in facing any opponent and not in a 'held' posture.
"Most gymnasts focus their eyes on the ‘cliff edge,’ a visual anchor point about five centimetres in front of the wrists and equidistant between them (Clement, Pozzo and Berhoz 1988). Gauthier and colleagues (2007) found under experimental conditions that vision, both focal and peripheral, accounts for approximately 47% of balance in a handstand, but that the proprioceptive sense of one’s own neck was also significant, helping maintain balance when the head is flexed backwards (the Olympic head positioning) (see also Clement and Rezette 1985). Steven Vogel (2001:82-83) points to the high concentration of muscle spindles in the nape of our necks, the stationary position of the head in vigorous movements, and the head-first righting reflex of many animals to suggest that head position is a crucial link between vestibular information in the head and the whole body’s position"
Successful capoeira movement - use of hands and hand movements and bending elbows - suggests that equilibrium is plastic neural networks - sensory inputs differently weighted that interpret, process information - translating to behavioural patterns,
(reference list at end of article)
Also Proprioception and Kinaesthetic Awareness - Weakness with a Twist, http://serendip.brynmawr.edu/exchange/node/1699
"The proprioception sensory system is carried out utilizing proprioceptors in the muscles that monitor length, tension, pressure, and noxious stimuli. The muscle spindles, the most complex and studied of the proprioceptors, informs other neurons of the length of the muscle and the velocity of the stretch. The density of muscle spindles within a muscle increases for muscles involved in fine movements, as opposed to those involved in larger course movements. The brain needs input from many of these spindles in order to register changes in angle and position that the muscle has accomplished"
Mohsen Kazemi firstname.lastname@example.org BMC Musculoskeletal Disorders 2005, 6:26 doi:10.1186/1471-2474-6-26
"Taekwondo consists of repeated-effort, high intensity physical demands. In addition to this, Taekwondo competition is structured in a similar fashion to boxing and rowing in that athletes are required to meet weight requirements in order to compete.
Twenty-five percent (n = 7) of the competitors reported sparring one to two times per week. Over 53% (n = 15) of respondents sparred three to four times per week, and over 21% (n = 6) sparred five or more times per week. Pre- and post-training stretching was also reported. Over 40% (n = 11) of respondents reported only stretching prior to their training sessions, and close to 60% (n = 16) of respondents stretched both before and after training. When examining the use of warm-up and cool-down exercises, over 57% (n = 16) of participants noted always warming up prior to training, while almost 43% (n = 12) reported only warming up occasionally. Only six of 28 respondents (21%) reported they always engaged in post-training cool-down exercises, other than stretching. Over sixty-four and fourteen percent (n = 22) of respondents reported occasionally and never using cool down exercises, respectively. "
Unknown whether weight cycling practiced amongst taekwondo competitors.
60% used protective gear.
Injuries more common in training than competition
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