Backward Fall Research Articles

Mechanical Response Analysis on The Hip Joint upon Collision with the Floor after a Backward Fall using a Three-Dimensional Human Body Model

Mechanical Response Analysis on The Hip Joint upon Collision with the Floor after a Backward Fall using a Three-Dimensional Human Body Model

Susceptibility to Head Injury during Backward Fall with Side Aligning of the Body

(1) Background: The aim of this article is to investigate the susceptibility to head injuries in physical education students who do not train a specific sports discipline and those who use the fall performed backward with side aligning of the body technique. The other goal is the biomechanical analysis of the impact of the fall technique on the likelihood of head injury. (2) Methods: the study included 57 students, divided into two research groups. Group A consisted of 32 students who had not practiced any sport in a sports club before. Group B consisted of 25 students who, by practicing martial arts, had acquired the skill of the fall performed backward with side aligning of the body. A rotating training simulator (RTS) was used to force the fall backwards. (3) Results: students from group B made significantly fewer “head” errors when falling backwards than in group A. Increasing the speed of falling did not increase the number of “head” errors in group B, but only in group A. The type of the fall test performed affected the increase in the number of “head” errors only in group A. (4) Conclusions: practicing selected sports disciplines in which the fall backwards occurs can protect one against head injuries by acquiring appropriate motor habits. The use of the fall performed backward with side aligning of the body technique with the occurrence of horizontal inertia forces causing a fall reduces the risk of head injuries.

Leg Joint Stiffness Affects Dynamics of Backward Falling From Standing Height: A Simulation Work.

Falling backward can lead to injuries including hip fracture, back injury, and traumatic brain impact among older adults. A loss of consciousness is associated with falling backward and accounts for about 13% of all falls among older adults. Little is known about the dynamics of backward falls, such as the falling duration, the impact severity, and how the fall dynamics are affected by the biomechanical properties of the lower limb joints, particularly the rotational stiffness. The purpose of this study was to investigate the influence of the stiffness of individual leg joints on the dynamics of backward falls after losing consciousness in terms of the falling duration and impact velocities. Based on a 15-segment human model, we simulated the process of falling backward by sweeping the parameter space of ankle, knee, and hip's stiffnesses varying from 0 to 8.73 N·m·deg-1 (or 500 N·m·rad-1). The results revealed that the falling duration and impact speeds of the head and hip ranged from 0.27 to 0.63 s, 2.65 to 7.88 m·s-1, and 0.35 to 3.36 m·s-1, respectively, when the stiffness of the leg joints changed within their limits. Overall, the influence of the joint stiffness on the falling dynamics (falling duration and impact speed) is comparable between hip and knee joints, whereas ankle stiffness showed little influence on the backward falling dynamics. Our findings could provide references for designing protective devices to prevent impact-induced injuries after a backward fall.

Backward walking sensitively detects fallers in persons with multiple sclerosis

BackgroundIndividuals with multiple sclerosis experience deficits in mobility resulting in injurious falls. Fall detection has proved challenging; the majority of clinical measures rely on forward walking and balance measures, yet these measures have poor sensitivity and predictive value for differentiating between fallers and non-fallers. Backward walking better differentiates fallers from non-fallers in the elderly and other neurodegenerative diseases; therefore, the objective of this study was to examine both forward and backward walking to determine the strongest, unique contributor that differentiates fallers from non-fallers in persons with multiple sclerosis. MethodsIn a single session, spatiotemporal measures of forward and backward walking and fall history were collected. For the subsequent six months, individuals recorded falls in a fall diary. Discriminant function analysis was used to determine what variables most strongly and uniquely differentiate multiple sclerosis fallers from non-fallers. ResultsThirty-eight individuals with multiple sclerosis participated. Forward and backward velocity, stride length, and double support time as well as age, disease severity, and symptom duration were included in the models. Together, the variables differentiated between fallers and non-fallers (Wilk's lambda χ2 (8, N = 36) = 0.497, p<0.001) and in rank order, backward walking velocity was the strongest unique predictor. Repeating the analysis with a stepwise approach yielded that backward walking velocity in the first step (χ2 (1, 34) = 0.68, F = 15.96, p<0.001) and symptom duration in the second step (χ2 = 0.59, F (2, 33) = 11.46; p<0.001) most strongly differentiated retrospective fallers and non-fallers. This stepwise model with backward walking velocity and symptom duration accurately classified 76.3% of cases. Addition of forward walking measures did not significantly improve the models, and indeed the accuracy of classification was reduced to 71.1%. Exploratory analysis showed that backward walking velocity was the best predictor of prospectively reported fallers and non-fallers (χ2 (1, 7) = 0.43, F = 9.20, p = 0.02). ConclusionBackward walking velocity exhibits the highest effect magnitude and specificity in differentiating fallers from non-fallers in individuals with MS and demonstrates potential as clinically feasible and efficient fall detection tool.

Epidemiology and risk factors of coccyx fracture: A study using national claim database in South Korea

IntroductionCoccyx fracture usually is a low-energy trauma caused by a backward fall onto a slippery floor of ice. The exact epidemiology of the coccyx fracture is not known. Moreover, the effects of seasonality and weather on the fracture incidence have not been reported. The purpose of this study was to evaluate the annual incidence, gender-preponderance, age-distribution, seasonal variation and climatic risk factors of the coccyx fracture. MethodsWe identified coccyx fractures, which occurred in South Korea from 2010 to 2018, using nationwide data of Korean Health Insurance Review and Assessment Service (HIRA). International Classification of Diseases-10th Revision (ICD-10) code S322 was used for the identification. Annual incidence of the coccyx fracture was calculated, and the fractures were correlated with gender, age, month of diagnosis and climatic factors. ResultsA total of 238,906 patients were diagnosed with coccyx fracture with an average of 26,545 patients at year. Male to female ratio was 1:2.6. The annual incidence of coccyx fracture was 119.75/100,000 persons in 2018; 33.44/100,000 in male and 86.30/100,000 in female. The incidence rate was the highest at puberty (age of 10-14 years) in male, and at menopause (age of 50-54 years) in female. The incidence was frequent in winter followed by summer. The incidence of coccyx fracture was negatively correlated with the temperature (Pearson correlation factor= -0.67, P<0.01) in winter, while it was positively correlated with the temperature in summer (Pearson correlation coefficient = 0.66, p<0.01). In generalized linear model, old age, female gender, recent year, summer and winter, low temperature and high amount of precipitation appeared as risk factors for coccyx fracture. ConclusionsThe epidemiologic patterns of coccyx fracture were comparable to other osteoporotic fractures. Findings of our study can be used for epidemiological awareness and prevention campaigns of coccyx fracture.

Smart Fall Prediction for Elderly Care Using iPhone and Apple Watch

Along with the annually increasing elderly population, the issues particularly regarding the elderly care are gaining inevitable attention. Nursing and taking care of the elderly people is now the emphasized issue. Besides, the social phenomena of large urban–rural gap and population emigration cause serious shortage of nursing manpower. Among the needs for good care, falls present extreme risks in the elderly population. The shortage of nursing manpower causes the impossible provision of real-time-care for the elderly fall accidents. This study uses the three-axis accelerometer in Apple watch to measure the movement and to input it to the High-Level Fuzzy Petri Net (HLFPN) prediction model. Based on the HLFPN model, fuzzy reasoning is performed to predict the users’ daily motions including walking, sitting down, and falls. With the application to elderly exercise model, this system would transmit real-time positioning datasets when there are falls for the rapid and proper treatment so as to minimize the elderly injury caused by falls. Based on the experimental datasets regarding forward fall, backward fall, right-sided fall, and left-sided fall, the obtained precision values are 95.45%, 97.72%, 94.67%, and 95.12%, respectively. Walking, running, and falls could also be distinguished in this study. It is expected that this study could assist in solving the problem of nursing manpower shortage, providing immediate assistance for the elderly on the occasion of falls.

Abdominal pain due to the spinothalamic tract injury in patients with mild traumatic brain injury: a case report

BackgroundWe report on a patient with a mild traumatic brain injury (TBI) who developed abdominal pain due to spinothalamic tract (STT) injuries revealed by diffusion tensor tractography (DTT).Case presentationA 53-year-old female patient suffered head trauma resulting from a backward fall. While bathing at a public bathhouse, she fell backward and struck the occipital area of her head against the floor. After the head trauma, she experienced pain in the abdomen and in both hands and feet. She underwent evaluations including conventional brain MRI, abdominal and pelvic ultrasonography, and stomach and intestine endoscopy. No abnormality was observed in her brain or abdomen. In addition, her abdominal pain had not been relieved by medical management. When she came to our hospital 4 years after the head trauma, her pain characteristics and severity were as follows: intermittent pain without allodynia or hyperalgesia; squeezing and warm creeping-like pain in the abdomen (visual analog scale score: 7); tingling pain in both hands and feet (visual analog scale score: 7). She was prescribed pregabalin and gabapentin, and her abdominal and limb pain was well-controlled at a tolerable level. On DTT 4 years after head trauma, the upper portion of the spinothalamic tracts (STTs) in both hemispheres showed partial tearing.Discussion and conclusionsInjury of the STT was demonstrated by using DTT in a patient who showed abdominal pain that was refractory to medical management following mild TBI. Our results suggest that central pain due to STT injury might be suspected in patients with abdominal pain that is refractory to medical management following TBI.

Is There an Optimal Recovery Step Landing Zone Against Slip-Induced Backward Falls During Walking?

Recovery stepping in response to forward slips has the potential to not only rebuild the base of support to prevent backward falling, but also provide extra limb support to prevent downward falling. Hence, recovery stepping is often necessary for fall prevention following an unexpected slip. However, less is known about whether recovery foot placement could affect the likelihood of recovery following a slip. The purpose of this study was to determine whether there is an optimal recovery landing zone within which older adults have a higher likelihood of recovery. 195 participants experienced a novel, unannounced forward slip while walking on a 7-m walkway. The center of mass (COM) stability (computed from its position and velocity), vertical limb support (computed from change in hip kinematics), and recovery limb joint moments (computedfrom joint kinematics and ground reaction force) in the sagittal plane were analyzed. The results showed that a longer distance between recovery foot landing position and the projected COM position at recovery foot touchdown (relative recovery step placement) was conducive to stability improvement but adverse to limb support enhancement, and vice versa for a shorter distance. Relative recovery step placement could predict the recovery likelihood with an accuracy of 67.3%, and the recovery rate was greater than 50% when the distance between recovery foot and COM is less than 0.3 × foot length. This study also found more posterior stepping could be attributed to insufficient ankle plantar flexor and hip flexor moments in the pre-swing phase, while more anterior stepping was induced by insufficient hip and knee extensor moments in the following swing phase.

Effects of Fall Training Program on Automatization of Safe Motor Responses During Backwards Falls in School-Age Children.

A significant number of children suffer injuries from falls. The current measures of prevention and education regarding falls are not sufficient, as falling is still the main cause of injury at this age. This study aimed to evaluate the risk of injury during a backward fall and assess the effect of the Safe Fall training program on this risk. 457 primary school children between the ages of 6 and 12 (mean age of 9) were enrolled in a 6-week randomized intervention. The program was carried out during physical education classes and consisted of an intervention group that followed the Safe Fall training program and a control group that was given equilibrium exercises. The risk of injury was assessed before and after the implementation using the Information Scale on Safe Ways of Falling observation scale, evaluating the responses of five different body parts (head, hip, knees, upper limbs and back). Students’ natural response to falls was associated with a high risk of injury in more than 90% of the cases. The implementation of the Safe Fall program resulted in a considerable decrease in this risk, with percentages lowered to levels between 8.7% and 18.3%.

Characterizing the demands of backward balance loss and fall recovery during stair descent to prevent injury

Understanding the demands of balance recovery on stairs is important for developing strategies to prevent falls on stairs. This study characterized recovery strategies and whole-body movement following unexpected backward balance loss during stair descent in twelve young adults. Following balance loss, peak downward COM velocity was approximately double that experienced during non-perturbation stair descent. Participants used several balance recovery strategies: harness reliance (n = 1), no grasping reaction (n = 3), and grasping some environmental feature (n = 8). Of the five participants who used the handrail, four demonstrated grasping errors. Peak resultant handrail forces ranged from 24.2N to 238.3N. The results highlight the challenge of balance recovery during stair descent, showing that some people will use any available surface to arrest a fall. Our findings serve as a benchmark to understand the impact of stair-related interventions on fall recovery.

COMPARATIVE STUDY OF THREE DIFFERENT PREGNANCY DIAGNOSIS TECHNIQUES IN RABBITS

Seven pluriparous non-gravid does and two matured bucks were utilized for the study. Does were all mated after 30 days of stabilization. Successful mating was confirmed by a recoil, backward or sideway fall and emission of a snorting sound by the male. Pregnancy detection was by weight gain, abdominal palpation and ultrasonography techniques at days 6, 9,13,18,23. Abdominal palpation of does was carried out by gentle palpation of nodule-like tissues in the ventral abdomen. Transcutaneous ultrasonography was performed using ultrasound machine Kaixin KX2000®. Weight gain was monitored using a sensitive weighing scale. Early pregnancy was diagnosed by ultrasonography and abdominal palpation on days 6.00±0.00 and 7.5±1.29 post-copulation respectively. Pregnancy was diagnosed by abdominal palpation in 28.57% of the does on day 6 and increased to 100% on day 9 post-copulation; however diagnosis by ultrasonography was 100% on day 6. The average weight gain was 0.029±0.029kg by day 6; 0.057±0.4 by day 13, which plateaued till parturition. Ultrasonography could therefore be used effectively for pregnancy diagnosis as early as day 6 of gestation in rabbit does while abdominal palpation could serve in absence of ultrasonography by day 9 of gestation. Weight gain is a positive adjunct to other pregnancy diagnostic techniques.&#x0D; &#x0D; &#x0D;

Wearable-sensor-based pre-impact fall detection system with a hierarchical classifier

Fall is a major threat to elder health, and fall detection has attracted considerable research attention recently. In our study, a novel method is proposed to detect falls prior to impact during walking. Angle and angular-velocity data from the waist and thigh are collected using two wearable sensors. By extracting and selecting distinctive features, we aim to identify falls at an early stage. To improve detection accuracy and reduce false alarms, a hierarchical classifier based on Fisher discriminant analysis is developed. With the hierarchical classifier, human activities are classified into three categories: non-fall, backward fall and forward fall. It can achieve average lead times of 376 ms for backward fall and 404 ms for forward fall. Meanwhile, it can achieve a sensitivity of 95.5% and specificity of 97.3%. The method can achieve a high accuracy for classifier, and a long lead time for pre-impact fall detection. Compared with single-sensor-based methods, the multi-sensor-based method achieves a better performance. The preliminary results indicate that our study has potential application in a fall-injury prevention system.

The concept of margins of stability can be used to better understand a change in obstacle crossing strategy with an increase in age

The purpose of the current study was to use the margins of stability (MoS) to investigate how older adults choose between minimizing the risk of a forward fall when crossing an obstacle and the ease of maintaining forward progression during the steps taken behind the obstacle. In the current study 143 community-dwelling older adults aged between 55 and 83 years old, were divided into three age groups based on tertials of age. All participants were asked to complete five trials of obstacle walking and five trials of normal walking. For the trials of normal walking, the main difference between groups was that MoS at initial contact was lower in the older age groups. For the trials of obstacle crossing the MoS at the instants of obstacle crossing with both the leading and trailing limb became smaller with an increase in age. This result might imply that older people choose to use a strategy during obstacle crossing that results in smaller chance of falling forward if an obstacle was struck. A negative consequence of this more conservative strategy was a smaller MoS at the instants of initial contact after crossing the obstacle, thus a larger chance of a backward fall. These findings provide more insight into the regulation of stability during obstacle crossing and specifically in the differences in strategy between younger and older people, and therefore these results might be used for further research to investigate whether obstacle crossing strategies are trainable in older adults, which could be used as advisory programs aimed at fall prevention and/or engagement in an active lifestyle.

지면 경사도에 따른 후방 낙상 시 소뇌성 운동실조증 환자의 자세제어 특성 연구

The Cerebellar damage leads to falls due to the impairments in balance control, and secondary damage is a terrifying factor that may cause injuries. Concerning the fear of falls in patients with cerebellar disease (CD), this study examined the kinematic characteristics on body control abilities such as the movements of the upper and lower limbs and the motion of stepping to recover the balance when a back fall is occurred with increased ground inclination. Eight patients diagnosed with CD and 8 age-matched normal controls (NC) participated in the study. We evaluated the ability to recover the balance independently through stepping movements by causing the situation of a backward fall with the lean-and-release method and four different ground inclination conditions. The results demonstrated that there were no differences between two groups in overall stepping characteristics such as total steps, initiation time and step distance. However, the distance between the foot and body COM was shorter and velocity of COM movement at landing of first step was higher in CD than NC as the ground inclination increased. These findings indicate that patients with cerebellar disease used an inefficient movement strategy that does not help to recover their trunk motion from falling when fear of falling is elevated.

Spinal injury analysis for typical snowboarding backward falls.

Spinal injury (SPI) often causes death and disability in snow-sport accidents. SPIs often result from spinal compression and flexion, but the injury risks due to over flexion have not been studied. Back protectors are used to prevent SPIs but the testing standards do not evaluate the flexion-extension resistance. To investigate SPI risks and to better define back-protector specifications, this study quantified the flexion-extension range of motions (ROMs) of the thoracic-lumbar spine during typical snowboarding backward falls. A human facet-multibody model, which was calibrated against spinal flexion-extension responses and validated against vehicle-pedestrian impact and snowboarding backward fall, was used to reproduce typical snowboarding backward falls considering various initial conditions (initial velocity, slope steepness, body posture, angle of approach, anthropometry, and snow stiffness). The SPI risks were quantified by normalizing the numerical spinal flexion-extension ROMs against the corresponding ROM thresholds from literature. A high risk of SPI was found in most of the 324 accident scenarios. The thoracic segment T6-T7 had the highest injury risk and incidence. The thoracic spine was found more vulnerable than the lumbar spine. Larger anthropometries and higher initial velocities tended to increase SPI risks while bigger angles of approach helped to reduce the risks. SPIs can result from excessive spinal flexion-extension during snowboarding backward falls. Additional evaluation of back protector's flexion-extension resistance should be included in current testing standards. An ideal back protector should consider the vulnerable spinal segments, the snowboarder's skill level and anthropometry.

Children's Improvement of a Motor Response during Backward Falls through the Implementation of a Safe Fall Program.

The World Health Organization has warned that, in children, the second cause of death from unintentional injuries are falls. The objective of this study was to analyze the motor response of primary schoolchildren when a backwards fall occurs. These analyses occurred before and after interventions of the Safe Fall program, which aims to teach safe and protected ways of backward falling. A quasi-experimental research design was used, with a sample of 122 Spanish (Sevillian) schoolchildren in the 10–12 age bracket. The INFOSECA ad-hoc observation scale was used for data collection: this scale registers 5 essential physical reactions throughout the process of a safe and protected backwards fall. After that, a number of descriptive, correlational and contrast statistics were applied. The value used in the McNemar test to establish statistical significance was p < 0.05. Results showed that over 85% of students had developed the competence to correctly perform all five physical motions that allow for a safer backward fall. The teaching of safe and protected techniques for falling backwards in child population in Primary Education is possible through the implementation of the Safe Fall program in Physical Education classes, which can help making falls safer, diminishing the risk and severity of the injuries they cause.

Numerical Reconstruction of Traumatic Brain Injury in Skiing and Snowboarding.

Proper evaluation of ski helmet designs and safety standards should rely on head impact conditions involved in skiing and snowboarding head injuries. To study these impacts, main crash scenarios involving head injuries are numerically replicated. Multibody models of skiers and snowboarders were developed to investigate five common crash scenarios involved in traumatic brain injury: forward and sideways skiing falls, snowboarding backward falls, collisions between users and collisions with obstacles. For each scenario, the influence of crash conditions on head impact (location, speed, linear and rotational accelerations) and risk of injury are evaluated. Crash conditions were initial velocity, user height, position and approach angle, slope steepness, obstacles, and snow stiffness. One thousand one hundred forty-nine crashes were simulated and three significant levels of impact conditions were discriminated over the investigated crash scenarios: 1) the smallest normal-to-slope impact velocities (6 km·h; 22 km·h) and peak linear accelerations (42g; 75g) were obtained during forward and sideways skiing falls; 2) snowboarding backward falls and collisions between users were associated with high normal-to-surface impact velocities (26 km·h; 32 km·h) and head accelerations (80g; 149g) above one published threshold for mild traumatic brain injury but below the pass/fail criteria of helmet standard tests; 3) collisions with obstacles were associated with high normal-to-surface impact velocities (19 km·h; 35 km·h) and the highest head accelerations (626g; 1885g). Current impact conditions of helmet standard evaluations consistently replicate collisions with obstacles, but need to be revised to better reflect other significant crash scenarios leading to traumatic brain injury.

Effect of the Safe Fall Programme on Children’s Health and Safety: Dealing Proactively with Backward Falls in Physical Education Classes

The aim of this study is to show that the implementation of the Safe Fall programme in physical education classes can help to reduce the negative effects of unintentional backward falls in the adolescent population, by teaching them how to protect themselves when falling. A quasi-experimental research design was applied in a sample of 120 children (M = 15.1 years, SD = 2.45), attending a secondary school in Seville (Spain). Data was collected on an ad hoc observation scale INFOSECA (which records five basic elements during a backward fall: position of the neck, the hands, the trunk, the hips, and the knees), applying descriptive, correlational, and contrast statistics. The criteria for considering statistical significance was p &lt; 0.05 in McNemar’s test. The data indicates that learning safe and protected ways of falling backward is possible through the implementation of the Safe Fall programme, and no differences were found in terms of gender.

Posture based health monitoring and unusual behavior recognition system for elderly using dynamic Bayesian network

Video surveillance cameras play a vital role in society. Elderly monitoring is one of the major applications of surveillance camera. It is observed that most of the elderly people live alone at homes. They desire aging at homes. Due to aging elderly people may experience some abnormal behaviors like chest pain, headache etc. Since they live alone these abnormal activities are unnoticed. This unnoticed activities cause severe health problems and finally may cause death. So a monitoring system is needed to monitor the behavior and give alerts to the care givers. A computer vision based elderly health care monitoring system using Dynamic Bayesian network (DBN) is developed. Modelling sequential data is an important feature in machine learning domain. The DBN model detects the abnormal activities such as backward fall, chest pain, forward fall, headache, and vomit. Human postures are recognized from silhouettes so that the privacy of the people is preserved and this model is robust to different environmental setup. This DBN model is both generative and discriminative and evaluated with real time video sequences and gives 82% accuracy. This system helps to give immediate attention to the people who are suffering in home alone due to severe health issues.

Body configuration at first stepping-foot contact predicts backward balance recovery capacity in people with chronic stroke.

ObjectiveTo determine the predictive value of leg and trunk inclination angles at stepping-foot contact for the capacity to recover from a backward balance perturbation with a single step in people after stroke.MethodsTwenty-four chronic stroke survivors and 21 healthy controls were included in a cross-sectional study. We studied reactive stepping responses by subjecting participants to multidirectional stance perturbations at different intensities on a translating platform. In this paper we focus on backward perturbations. Participants were instructed to recover from the perturbations with maximally one step. A trial was classified as ‘success’ if balance was restored according to this instruction. We recorded full-body kinematics and computed: 1) body configuration parameters at first stepping-foot contact (leg and trunk inclination angles) and 2) spatiotemporal step parameters (step onset, step length, step duration and step velocity). We identified predictors of balance recovery capacity using a stepwise logistic regression. Perturbation intensity was also included as a predictor.ResultsThe model with spatiotemporal parameters (perturbation intensity, step length and step duration) could correctly classify 85% of the trials as success or fail (Nagelkerke R2 = 0.61). In the body configuration model (Nagelkerke R2 = 0.71), perturbation intensity and leg and trunk angles correctly classified the outcome of 86% of the recovery attempts. The goodness of fit was significantly higher for the body configuration model compared to the model with spatiotemporal variables (p<0.01). Participant group and stepping leg (paretic or non-paretic) did not significantly improve the explained variance of the final body configuration model.ConclusionsBody configuration at stepping-foot contact is a valid and clinically feasible indicator of backward fall risk in stroke survivors, given its potential to be derived from a single sagittal screenshot.