What is a FOOSH injury? FOOSH is an acronym for Fall On OutStretched Hand and a FOOSH injury is an injury caused by falling on an outstretched hand.
In an article in the Journal of Biomechanics, James Chiu and Stephen N Robinovitch (1) explain that falls on outstretched hands are a significant cause of upper extremity injury, including approximately 90% of fractures at the distal radius, humeral neck, and supracondylar region of the elbow. They suggest that among these, fractures at the distal radius is especially significant, as it represents the most common type of fracture for the under-75 population. This mechanism of injury is so common that the medical fraternity use the FOOSH acronym to describe all such these injuries.
In another study, Robinovitch teamed up with ET Hsiao (2) to investigate the natural response when falling unexpectedly from standing height. They found, as expected, that the predominant balance recovery technique was stepping with only one of their trials involving stabilisation of posture through sway. However, the effectiveness of stepping in preventing a fall was highly directional dependent. Falls were avoided in 78% of the cases where stability was disturbed to the front and 72% of the cases where stability was disturbed laterally, but only 37% of the cases where stability was disturbed to the rear. Subjects were more than twice as likely to fall when balance was lost to the rear than when lost to the front or side. Hsiao and Robinovitch suggest the observed directional nature of stability may be related to an inability to visualise the environment behind the body, or achieve large step sized during rearward stepping.
The direction of balance disturbance also effected the type of fall. Hsiao and Robinovitch used the terms 'partial fall' to refer to a fall which involves contact with hands and/or knees but no trunk and/or pelvis contact, and 'complete fall' to refer to a fall which involves contact to the trunk and/or pelvis. Complete falls run the risk of injury to the pelvis whereas partial falls do not. They found that 92% of the falls to the rear were complete falls, 23% of falls to the side were complete falls, and no complete falls were observed in falls to the front.
Wrist contact was observed in ALL complete and partial falls. Braking the fall with the outstretched hand allowed for complete avoidance of upper body impact in falls to the front and reduced the incidence of upper body impact by over fourfold in falls to the side. In falls to the rear, subjects were just as likely to first impact their pelvis as they were their wrists. Hsiao and Robinovitch suggest the time difference between impacts is of greater significance than the order of impact. Previous studies have shown that 50 ms is required to reach peak force after contact with either the hip or wrist during a fall. Hsiao and Robinovitch observed the time difference in their falls to the rear trials was less than 50ms in over 75% of the cases. This suggests the near simultaneous impact between wrist and pelvis is chosen to allow sharing of impact energy between the upper extremity and pelvis.
Robinovitch had concerns over the findings of the falls to the side in the above study. He teamed up with Fabio Feldman (3) to investigate the protective response that allow young adults to avoid hip impact during a sideways fall. In their study they found that only 5% of participants were able to avoid falling altogether and another 5% fell but did not impact the pelvis. The remaining 90% fell and impacted the pelvis. However, they also found that the hand impacted before the hip in the vast majority of the falls, and the knee impacted before the hip in most falls.
A martial arts breakfalling technique is a technique designed to reduce the risk of injury during a fall. Nature's breakfalling technique then, based on these studies, is to fall on outstretched hands. Falling on knees and buttocks is also used in attempting to land safely but the predominant technique of nature's breakfalling techniques if falling on outstretched hands.
But falling on outstretched hands runs the risk of incurring a FOOSH injury.It is an evolutionary trade-off. This reflexive protective response in stretching out our hands to allow for a safe landing from a fall has been selected for in nature. Nature, or evolution, is prepared to sacrifice the upper extremity in order to protect the head, neck, and torso. Trauma to these regions poses the greatest danger to our physical well-being. Injuries to the upper extremities result in disability but rarely with fatal consequences. Injuries to the head, neck, or trunk, in contrast, have real and immediate potential to be fatal. (4)
Nature's, or evolution's, breakfalling technique is effective. It allows Mr and/or Ms Caveman to live to fight another day after falling, albeit with a damaged wing.
Nature's breakfalling technique and FOOSH injuries has implications for the martial arts. Firstly, the martial arts breakfalling techniques is an attempt at improving on nature. Martial arts breakfalling techniques are designed to reduce the risk of injury to the head, neck, and torso and the upper extremities in a fall. Arthur A Chapman, in Biomechanical Analysis of Fundamental Human Movement, suggests that all good physical education classes should teach basic martial arts landing strategies. Marlene J Adrian and John M Cooper likewise recommend the benefits of martial arts breakfalling techniques to the wider community in Biomechanics of Human Movement: 'Falling and landing effectively with a minimum of injury are necessary skills to attain longevity in sports, injury, and daily living' (p. 279).
Injuries and fatalities from falls is a major health issue around the world. Interestingly, only two groups of researchers have studied martial arts breakfalling techniques in an attempt to develop techniques to reduce the risk of injury during a fall for the general population. In 1999, MB Sabick (5) and her American colleagues used seven young adult male and two young female aikidoka (aikido practitioner) to investigate impact forces at the hip and shoulder in falls to the side. More prolific studies have been conducted by a team of Dutch researchers led by Brenda Groen and Vivian Weerdesteyn. They have developed a method of falling based on judo breakfalling techniques which has been included in the Nijmegen Falls Prevention Program (NFPP) which is being taught in Holland. Various studies conducted by Groen and Weerdesteyn investigating the efficacy of the breakfalling technique taught within the NFPP have found that elderly participants could learn to the basics of this technique in falls to the front, side, and rear in five weekly sessions of 45 minutes duration. An interest result coming from one of these studies (6) is that the fear of falling was significantly reduced after the martial arts fall training. The authors of the study suggest that since the fear of falling has been shown to be an independent predictor of falling, the reduction in fear of falling might have an additional effect on hip fracture prevention.
These and other studies are discussed in chapter two 'Breakfalling Techniques' of my book on the science behind the tactics and techniques of the martial arts. Chapter eleven, 'Injury Science', is also applied in chapter two to facilitate the understanding and study of breakfalling techniques. Along with the basic breakfalling techniques is a unique technique taught by Jan de Jong - a sideways roll. Most martial arts follow judo's lead and teach forward and backward rolls, Jan de Jong jujutsu is unique in teaching a sideways roll.
Secondly, since the majority of injuries to the upper extremities are FOOSH injuries, there is very little information available on the types of injuries which may be inflicted when applying a joint-locking technique (kansetsu waza). The forces applied to the upper extremity in both instances are entirely different. For instance, when an arm breaking (ude kujiki) technique is applied, the forces are applied to the opponent's elbow in a lateral direction whereas in a FOOSH scenario, the forces are applied at the hand up the arm. The different forces result in entirely different injuries. Also, FOOSH injuries occur when the hand is usually hyperextended, however, the wrist joint-locking techniques (e.g. wrist twist, or tekubi hineri or kote hineri) are nearly always applied with flexed wrists. The prevelance of FOOSH injuries may account for the fact that there are NO descriptions of the physiological effects of joint-locking techniques in the English-language literature to date - until my book of course. It has not been easy attempting to discern the physiological effects of joint-locking techniques, but it has been worth the effort in that it provides a unique contribution to the general body of knowledge, and the martial arts body of knowledge in particular.
Before I finish this lengthy (again) blog, I must thank Brenda Groen for her generous support. Having an interest in her work, I contacted her and she generously corresponded with me and assisted me in coming to grips with some of the studies that have been conducted on falls. She has also been kind enough to provide some positive feedback concerning my grasp and interpretation of these studies. In my journey in researching this book, I have found that many academics have been particularly generous in their support.
Until next time.
(1) J Chiu & SN Robinovitch 1998, 'Prediction of upper extremity impact forces during falls on the outstretched hand', Journal of Biomechanics, 31, 1169-1176.
(2) ET Hsiao & SN Robinovitch 1998, 'Common protective movements govern unexpected falls from standing height', Journal of Biomechanics, 31, 1-9.
(3) F Felman & SN Robinovitch 2007, 'Reducing hip fracture risk during sideways falls: Evidence in young adults of the protective effect of impact to the hands and stepping', Journal of Biomechanics, 40, 2612-2618.
(4) WC Whiting & RF Zernicke 1998, Biomechanics of Musculoskeletal Injury.
(5) MB Sabick, JG Hay, VK Goel, & SA Banks 1999, 'Active responses decrease impact forces at the hip and shoulder in falls to the side', Journal of Biomechanics, 32, 993-998.
(6) BE Groen, E Smulders, D de Kam, & V Weerdesteyn 2010, 'Martial arts fall training to prevent hip fractures in the elderly', Osteoporosis International, 21, 215-221.