The effects of time pressure and experience on the performance of fall techniques during a fall.

Although the practice of fall techniques has been introduced in fall prevention programs, it is not clear whether people can apply acquired techniques during a real-life fall. It would be helpful to know the time it takes to initiate and to successfully execute such techniques, as well as the effect of experience on the execution of these techniques. In this study we investigated the neuromuscular control of voluntary fall techniques in five seasoned judokas and nine non-judokas. After they had started falling from a kneeling position, they received an auditory cue prompting either a lateral natural fall arrest (block) or a martial arts (MA) fall. EMG data of shoulder and trunk muscles were collected. The requested technique was successfully applied in 85% of the falls. Following the cue, EMG amplitudes of the fall techniques started to diverge after 180-190 ms. EMG amplitudes were generally similar in both groups, but experience-related differences could be demonstrated in the pectoralis and trapezius. In conclusion, voluntary motor control is possible within the duration of a fall, even in inexperienced fallers. Differences in EMG activity might suggest that experienced fallers changed their reaction to possible falls from a preparation for arm abduction into a preparation for trunk rotation.

[1]  M. Järvinen,et al.  Majority of Hip Fractures Occur as a Result of a Fall and Impact on the Greater Trochanter of the Femur: A Prospective Controlled Hip Fracture Study with 206 Consecutive Patients , 1999, Calcified Tissue International.

[2]  J A Ashton-Miller,et al.  On reducing hand impact force in forward falls: results of a brief intervention in young males. , 2003, Clinical biomechanics.

[3]  B E Groen,et al.  Martial arts fall techniques decrease the impact forces at the hip during sideways falling. , 2007, Journal of biomechanics.

[4]  James A Ashton-Miller,et al.  On use of a nominal internal model to detect a loss of balance in a maximal forward reach. , 2007, Journal of neurophysiology.

[5]  A. Schultz,et al.  Effects of age and available response time on ability to step over an obstacle. , 1994, Journal of gerontology.

[6]  A. Schultz,et al.  Stepping Responses of Young and Old Adults to Postural Disturbances: Kinematics , 1994, Journal of the American Geriatrics Society.

[7]  S. Robinovitch,et al.  Time requirement for young and elderly women to move into a position for breaking a fall with outstretched hands. , 2005, The journals of gerontology. Series A, Biological sciences and medical sciences.

[8]  J. Kelsey,et al.  Characteristics of Falls and Risk of Hip Fracture in Elderly Men , 1998, Osteoporosis International.

[9]  M. Do,et al.  In a complex sequential movement, what component of the motor program is improved with intensive practice, sequence timing or ensemble motor learning? , 2001, Experimental Brain Research.

[10]  T. McMahon,et al.  Hip impact velocities and body configurations for voluntary falls from standing height. , 1996, Journal of biomechanics.

[11]  R. Stein,et al.  Analysis of rapid stopping during human walking. , 1998, Journal of neurophysiology.

[12]  M. Do,et al.  The influence of a reduced plantar support surface area on the compensatory reactions to a forward fall , 2004, Experimental Brain Research.

[13]  W. Sparrow,et al.  Age and walking speed effects on muscle recruitment in gait termination. , 2005, Gait & posture.

[14]  Romeo Chua,et al.  Startle response is dishabituated during a reaction time task , 2003, Experimental Brain Research.

[15]  E. Zehr,et al.  Ballistic movement performance in karate athletes. , 1997, Medicine and science in sports and exercise.

[16]  S. Banks,et al.  Active responses decrease impact forces at the hip and shoulder in falls to the side. , 1999, Journal of biomechanics.

[17]  Comparison of different tests of fencing performance. , 1991, International journal of sports medicine.

[18]  J. Duysens,et al.  Martial arts fall techniques reduce hip impact forces in naive subjects after a brief period of training. , 2008, Journal of electromyography and kinesiology : official journal of the International Society of Electrophysiological Kinesiology.

[19]  P. Kannus,et al.  A sideways fall and hip fracture. , 2006, Bone.

[20]  B. Bussel,et al.  Influence of plantar cutaneous afferents on early compensatory reactions to forward fall , 2004, Experimental Brain Research.

[21]  J. Allum,et al.  Age‐dependent variations in the directional sensitivity of balance corrections and compensatory arm movements in man , 2002, The Journal of physiology.

[22]  P. Kannus,et al.  Unintentional Injury Deaths in an Adult Finnish Population from 1971–1997 , 2000, Epidemiology.

[23]  A B Schultz,et al.  Muscle activities used by young and old adults when stepping to regain balance during a forward fall. , 2000, Journal of electromyography and kinesiology : official journal of the International Society of Electrophysiological Kinesiology.

[24]  Maarten F. Bobbert,et al.  Control of support limb muscles in recovery after tripping in young and older subjects , 2004, Experimental Brain Research.

[25]  Stephen N Robinovitch,et al.  Strategies for Avoiding Hip Impact During Sideways Falls , 2003, Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research.

[26]  J A Ashton-Miller,et al.  Fall arrest strategy affects peak hand impact force in a forward fall. , 2002, Journal of biomechanics.

[27]  Vladimir M. Zatsiorsky,et al.  Muscle synergies involved in preparation to a step made under the self-paced and reaction time instructions , 2006, Clinical Neurophysiology.

[28]  Shrawan Kumar,et al.  An electromyographic study of isokinetic axial rotation in young adults. , 2003, The spine journal : official journal of the North American Spine Society.