Age differences in energy absorption in the upper extremity during a descent movement: implications for arresting a fall

Leg Press and Chest Press Power Normative Values by Half Decade in Older Women

ABSTRACT

Parrino, RL, Martinez, KJ, Konlian, JA, Conti, JM, and Signorile, JF. Leg press and chest press power normative values by half decade in older women. J Strength Cond Res 38(5): 991-998, 2024-Neuromuscular power is essential for the performance of most activities of daily living and the maintenance of functional independence throughout the aging process. Power declines rapidly in later life; however, this decline may be reduced or delayed with early detection and intervention. Therefore, this study provides leg press and chest press power normative values for older women. Women's power data for this analysis included 229 participants, 60-90 years of age. Power testing was conducted on Keiser A420 pneumatic leg press and chest press machines following a standardized protocol. Data were stratified into half-decade age groups and analyzed using a 1-way ANOVA. Descriptive statistics and quartile rankings are reported, and significant differences between age groups are outlined. There were significant differences in absolute and relative leg press peak power between the age groups ( p < 0.05). However, there were no significant differences in absolute or relative chest press peak power between the age groups. This research established normative values and quartile rankings for leg press and chest press power in older women 60-90 years of age, allowing comparative evaluations with patients and subjects by clinicians and researchers, respectively. These values should improve exercise interventions designed to improve power production by providing assessments of subjects' current status and allowing comprehensive monitoring of progress.

Brain activation associated with low- and high-intensity concentric versus eccentric isokinetic contractions of the biceps brachii: An fNIRS study

Studies have shown that neural responses following concentric (CON) and eccentric (ECC) muscle contractions are different, which suggests differences in motor control associated with CON and ECC contractions. This study aims to determine brain activation of the left primary motor cortex (M1) and left and right dorsolateral prefrontal cortices (DLPFCs) during ECC and CON of the right bicep brachii (BB) muscle at low- and high-contraction intensities. Eighteen young adults (13M/5F, 21-35 years) were recruited to participate in one familiarization and two testing sessions in a randomized crossover design. During each testing session, participants performed either ECC or CON contractions of the BB (3 sets × 8 reps) at low- (25% of maximum ECC/CON, 45°/s) and high-intensity (75% of maximum ECC/CON, 45°/s) on an isokinetic dynamometer. Eleven-channel functional near-infrared spectroscopy was used to measure changes in oxyhemoglobin (O2 Hb) from the left M1, and left and right DLPFC during ECC and CON contractions. Maximum torque for ECC was higher than CON (43.3 ± 14.1 vs. 46.2 ± 15.7 N m, p = 0.025); however, no differences in O2 Hb were observed between contraction types at low or high intensities in measured brain regions. High-intensity ECC and CON contractions resulted in greater increases in O2 Hb of M1 and bilateral DLPFC compared to low-intensity ECC and CON contractions (p = 0.014). Our findings suggest no differences in O2 Hb responses between contraction types at high and low intensities. High-contraction intensities resulted in greater brain activation of the M1 and bilateral DLPFC, which may have implications for neurorehabilitation to increase central adaptations from exercise.

A method for simulating forward falls and controlling impact velocity

Assessment of protective arm reactions associated with forward falls are typically performed by dropping research participants from a height onto a landing surface. The impact velocity is generally modulated by controlling the total height of the fall. This contrasts with an actual fall where the fall velocity is dependent on several factors in addition to fall height and not likely predictable at the onset of the fall. A counterweight and pulley system can be used to modulate the fall velocity in simulated forward falls in a manner that is not predictable to study participants, enhancing experimental validity. However, predicting the fall velocity based on participant height and weight and counterweight mass is not straightforward. In this article, the design of the FALL simulator For Injury prevention Training and assessment (FALL FIT) system is described. A dynamic model of the FALL FIT and counterweight system is developed and model parameters are fit using nonlinear optimization and experimental data. The fitted model enables prediction of fall velocity as a function of participant height and weight and counterweight load. The method can be used to provide controllable perturbations thereby elucidating the control strategy used when protecting the body from injury in a forward fall, how the control strategy changes because of aging or dysfunction or as a method for progressive protective arm reaction training.•Construction of device to simulate forward falls with controllable impact velocity using material that are commercially available is described•A dynamic model of the FALL FIT is developed to estimate the impact velocity of a simulated forward fall using participant height and counterweight load•The dynamic model is validated using data from 3 previous studies.

Validity and Reliability of the Seated Medicine Ball Throw as a Measure of Upper Body Power in Older Women

ABSTRACT

Strand, KL, Ly, AS, Barry, SS, Liscano, JA, Trebotich, TL, Martin-Diala, C, Martin, E, and Signorile, JF. Validity and reliability of the seated medicine ball throw as a measure of upper body power in older women. J Strength Cond Res 37(4): 902-908, 2023-In women, aging is associated with diminishing upper body power, which may increase the risk of falls and fall-related injury; however, the validity and reliability of clinical tests to evaluate upper body power need to be confirmed. The seated medicine ball throw (SMBT) is an upper body performance test used to monitor muscle function among older individuals. The purpose of this study was to evaluate the validity and test-retest reliability of the SMBT in older women. Thirty-five women (age = 75.15 ± 6.39 years) participated in this study. Subjects performed SMBT trials using common ball masses (SMBT 4lb and SMBT 3kg ) over 3 sessions. Familiarization with the SMBT and chest press 1 repetition maximum (CP 1RM ) was provided on the first day. On day 2, subjects repeated the tests, but data were recorded. On day 3, SMBT was retested followed by an evaluation of chest press peak power (CP PP ) values at 30-80% of CP 1RM . Significant correlations ( p ≤ 0.05) were found between the CP PP and SMBT 4lb ( r = 0.775, p < 0.001) and SMBT 3kg ( r = 0.734, p < 0.001), and SMBT distance showed expected declines with age ( r = -0.724 to -0.626, p < 0.001), demonstrating its validity. High reliability between testing days was found, and Bland-Altman plots showed few points that fell outside the limits of agreement. In conclusion, the SMBT is a valid and highly reliable tool that can be used by health professionals to monitor deficits in upper body muscular power to improve treatment protocols in older women.

Protective responses of older adults for avoiding injury during falls: evidence from video capture of real-life falls in long-term care

BACKGROUND

falls are common in older adults, and any fall from standing height onto a rigid surface has the potential to cause a serious brain injury or bone fracture. Safe strategies for falling in humans have traditionally been difficult to study.

OBJECTIVE

to determine whether specific 'safe landing' strategies (body rotation during descent, and upper limb bracing) separate injurious and non-injurious falls in seniors.

DESIGN

observational cohort study.

SETTING

two long-term care homes in Vancouver BC.

METHODS

videos of 2,388 falls experienced by 658 participants (mean age 84.0 years; SD 8.1) were analysed with a structured questionnaire. General estimating equations were used to examine how safe landing strategies associated with documented injuries.

RESULTS

injuries occurred in 38% of falls, and 4% of falls caused injuries treated in hospitals. 32% of injuries were to the head. Rotation during descent was common and protective against injury. In 43% of falls initially directed forward, participants rotated to land sideways, which reduced their odds for head injury 2-fold. Upper limb bracing was used in 58% of falls, but rather than protective, bracing was associated with an increased odds for injury, possibly because it occurred more often in the demanding scenario of forward landings.

CONCLUSIONS

the risk for injury during falls in long-term care was reduced by rotation during descent, but not by upper limb bracing. Our results expand our understanding of human postural responses to falls, and point towards novel strategies to prevent fall-related injuries.

Malaysian older persons' perceptions about falls and their desired educational website characteristics: A qualitative study

Falls is a common and debilitating condition among the older population, intensifying the need to educate older persons about falls. Technology advancement enables effective and efficient delivery of falls education to the older population. However, there is paucity of information on the perception of Malaysian older population on falls and their preferred website characteristics such as font size, design, layout, colour, navigation, and use of graphics or videos. Physiological changes in vision, cognition and psychomotor skills can affect how the older persons use the website. As Malaysia is a multicultural country, the needs of the website characteristics and falls perception of older persons may differ greatly. The aim of this study was to explore the perceptions of the older persons about falls and their desired website characteristics. Twenty-five community-living older persons (n = 25) of age 60 years and above were involved in the focus group discussions. NvivoTM software was used for data management and thematic analysis was undertaken. Emerging themes included ’Perceptions of falls in older persons’, ’Actions taken when falls occurred’, ’Perceived prevention strategies for falls’ and ’End user requirements for falls educational website’. Falls were perceived as both an avoidable and a non-avoidable incident. Although the participants mentioned physical activity and home hazard modifications as strategies to prevent falls, they mainly discussed self-initiated precautionary approaches in falls prevention. Regarding desired website characteristics, the participants emphasized on easily readable text, appealing design, clear information, use of images/videos, and simple website navigation. Special requirements for colour selection and multi-language options were also raised. The delivery of falls education through website can be made possible by understanding the perception of older persons about falls and their requirements for the website. This is especially important as ethnic and cultural influences may play a role on their perceptions about falls and desired website characteristics.

Effects of the Mobility-Fit Physical Activity Program on Strength and Mobility in Older Adults in Assisted Living: A Feasibility Study

Physical activity programs focusing on fall prevention often overlook upper-limb strength, which is important for transferring, balance recovery, and arresting a fall. We developed and evaluated a physical activity program, Mobility-Fit for older adults in Assisted Living (AL) that includes upper-limb strengthening, agility, coordination, and balance exercises. Thirty participants (85 ± 6 years) were recruited from two AL facilities; 15 were assigned to Mobility-Fit (three times/week, 45 min/session for 12 weeks) and 15 maintained usual care. Twenty-two participants (11 in each group) completed the study. We compared outcome changes between groups and interviewed participants and staff to explore the effectiveness and feasibility of the program. Among participants who attended Mobility-Fit, knee extension strength increased by 6%, reaction time decreased by 16%, and five-time sit-to-stand duration decreased by 15%. Conversely, participants in the usual care group had a 6% decrease in handgrip strength. Changes of these outcomes were significantly different between two groups (p < 0.05). Participants enjoyed the program and staff suggested some changes to improve attendance. Our results indicate that Mobility-Fit is feasible to deliver and beneficial for older adults in AL and may guide future clinical trials to evaluate the effectiveness of upper limb strengthening on safe mobility of older adults in care facilities.

Test-retest reliability of the FALL FIT system for assessing and training protective arm reactions in response to a forward fall

The use of the hands and arms is an important protective mechanism in avoiding fall-related injury. The aim of this study was to evaluate the test-retest reliability of fall dynamics and evokd protective arm response kinematics and kinetics in forward falls simulated using the FALL simulator For Injury prevention Training and assessment system (FALL FIT). Fall FIT allows experimental control of the fall height and acceleration of the body during a forward fall. Two falls were simulated starting from 4 initial lean angles in Experiment 1 and with 4 different fall accelerations in Experiment 2. Fourteen younger adults (25.1±3.5 years) and 13 older adults (71.3±3.7 years) participated in Experiment 1 and 13 younger adults (31.8±5.7 years) participated in Experiment 2. Intraclass correlation coefficients (ICC) were used to the evaluate absolute agreement of single measures at each condition and averages across conditions. Average measures of fall dynamics and evoked kinematics and kinetics exhibited excellent reliability (ICC(A,4)>0.86). The reliability of single measures (ICC(A,1) > 0.59) was good to excellent, although 18% of single measures had a reliability (ICC(A,1)) between 0.00 and 0.57. The FALL FIT was shown to have good to excellent reliability for most measures. FALL FIT can produce a wide range of fall dynamics through modulation of initial lean angle and body acceleration. Additionally, the range of fall velocities and evoked kinematics and kinetics are consistent with previous fall research.•

The FALL FIT can be used to gain further insight into the control of protective arm reactions and may provide a therapeutic tool to assess and train protective arm reactions.

Age-related changes in protective arm reaction kinematics, kinetics, and neuromuscular activation during evoked forward falls

Fall related injuries in older adults are a major healthcare concern. During a fall, the hands and arms play an important role in minimizing trauma from ground impact. Although older adults are able to orient the hands and arms into a protective orientation after falling and prior to ground impact, an inability to avoid increased body impact occurs with age. Previous investigations have generally studied rapid arm movements in the pre-impact phase or absorbing energy in the post-impact phase. There are no known studies that have directly examined both the pre-impact and post-impact phase in sequence in a forward fall. The aim of this study was to identify age-related biomechanical and neuromuscular changes in evoked arm reactions in response to forward falls that may increase fall injury risk. Fourteen younger and 15 older adults participated. Falls were simulated while standing with torso and legs restrained via a moving pendulum system from 4 different initial lean angles. While there was not a significant age-related difference in the amount of energy absorbed post-impact (p = 0.68), older adults exhibited an 11% smaller maximum vertical ground reaction force when normalized to body weight (p = 0.031), and 8 degrees less elbow extension at impact (p = 0.045). A significant interaction between age and initial lean angle (p = 0.024), indicated that older adults required 54%, 54%, 41%, and 57% greater elbow angular displacement after impact at the low, medium, medium-high, and high initial lean angles compared to younger adults. These results suggested older adults may be at greater risk of increased body impact due to increased elbow flexion angular displacement after impact when the hands and arms are able to contact the ground first. Both groups exhibited robust modulation to the initial lean angle with no observed age-related differences in the initial onset timing or amplitude of muscle activation levels. There were no significant age-related differences in the EMG timing, amplitude or co-activation of muscle activation preceding impact or following impact indicating comparable neuromotor response patterns between older and younger adults. These results suggest that aging changes in muscular elements may be more implicated in the observed differences than changes in neuromuscular capacity. Future work is needed to test the efficacy of different modalities (e.g. instruction, strength, power, perturbation training, fall landing techniques) aimed at reducing fall injury risk.

The Role of Fall Biomechanics in the Cause and Prevention of Bone Fractures in Older Adults

PURPOSE OF REVIEW

Adults over age 65 experience the highest rates of bone fracture, and 90% of fractures in older adults are caused by falls from standing height or lower. Advances in fracture prevention rely on our ability to prevent falls, reduce the severity of falls, and enhance the resistance of bone to trauma. To help guide these efforts, we need improved understanding on the types of falls that cause fractures.

RECENT FINDINGS

In this review, we describe recent evidence on how the mechanics of falls in older adults influence the risk for fractures to the hip, wrist, vertebrae, and humerus. We discuss how fracture risk depends on fall height, fall direction, and landing configuration. We also review the benefits of exercise, wearable protective gear, and environmental modifications in preventing fractures in older adults. Our findings highlight promising new directions in fracture prevention, and the need for collaboration between the bone and falls research communities to implement proven strategies and generate new solutions.

Does functional performance and upper body strength predict upper extremity reaction and movement time in older women?

BACKGROUND

Reaction time to initiate upper limb movement and movement time to place hands on the landing surface may be important factors in forward fall landing and impact, contributing to injury reduction. The aim was to investigate the relationship of physical function and upper body strength to upper limb reaction and movement time in older female participants.

METHODS

75 female participants (72 ± 8 yrs) performed 5 arm response trials. Reaction time (signal to initiation of movement), and movement time (initial movement to contact), were collected using 3D motion capture. Additional variables were: handgrip; sit-to-stand; shoulder flexion and elbow extension strength measured by hand-held dynamometry; one-legged balance; fall risk; and physical activity scores. Prediction variables for reaction and movement time were determined in separate backward selection multiple regression analyses. Significance was set at P < 0.05.

FINDINGS

Significant regression equations for RT (r² = 0.08, P = 0.013) found a relationship between stronger handgrip (Beta = -0.002) and faster reaction time, accounting for 8% variance. For movement time (r² = 0.06, P = 0.036) greater shoulder flexion strength (Beta = -0.04) was related to faster movement time, explaining 6% variance. Stronger SF strength was related to a decrease in MT by 4%.

DISCUSSION

A relationship between arm strength measures and faster upper body reaction and movement time was shown, with 10-20% higher strength associated with a 5% faster response time. Even though this was a relatively weak relationship, given that strength is a modifiable component this provides a potential avenue for future intervention efforts. This in turn could have an impact on forward fall landing and potential reduction of injury risk.

The Effect of Fall Biomechanics on Risk for Hip Fracture in Older Adults: A Cohort Study of Video-Captured Falls in Long-Term Care

Over 95% of hip fractures in older adults are caused by falls, yet only 1% to 2% of falls result in hip fracture. Our current understanding of the types of falls that lead to hip fracture is based on reports by the faller or witness. We analyzed videos of real-life falls in long-term care to provide objective evidence on the factors that separate falls that result in hip fracture from falls that do not. Between 2007 and 2018, we video-captured 2377 falls by 646 residents in two long-term care facilities. Hip fracture was documented in 30 falls. We analyzed each video with a structured questionnaire, and used generalized estimating equations (GEEs) to determine relative risk ratios (RRs) for hip fracture associated with various fall characteristics. All hip fractures involved falls from standing height, and pelvis impact with the ground. After excluding falls from lower than standing height, risk for hip fracture was higher for sideways landing configurations (RR = 5.50; 95% CI, 2.36-12.78) than forward or backward, and for falls causing hip impact (3.38; 95% CI, 1.49-7.67). However, hip fracture risk was just as high in falls initially directed sideways as forward (1.14; 95% CI, 0.49-2.67), due to the tendency for rotation during descent. Falling while using a mobility aid was associated with lower fracture risk (0.30; 95% CI, 0.09-1.00). Seventy percent of hip fractures involved impact to the posterolateral aspect of the pelvis. Hip protectors were worn in 73% of falls, and hip fracture risk was lower in falls where hip protectors were worn (0.45; 95% CI, 0.21-0.99). Age and sex were not associated with fracture risk. There was no evidence of spontaneous fractures. In this first study of video-captured falls causing hip fracture, we show that the biomechanics of falls involving hip fracture were different than nonfracture falls for fall height, fall direction, impact locations, and use of hip protectors. © 2020 The Authors. Journal of Bone and Mineral Research published by American Society for Bone and Mineral Research.

A systematic review of upper extremity responses during reactive balance perturbations in aging

BACKGROUND

Balance responses to perturbations often involve the arms in an attempt to either restore balance or protect against impact. Although a majority of research has been dedicated to understanding age-related changes in lower limb balance responses, there is a growing body of evidence supporting age-related changes in arm responses. This systematic review aimed to summarize differences in arm responses between older and younger adults under conditions requiring counterbalancing, reaching to grasping, and protection against impact.

METHODS

Following a systematic review and critical appraisal of the literature, data regarding the arm response in studies comparing young and older adults was extracted. The resulting articles were also assessed for quality to determine risk of bias.

RESULTS

Fifteen high quality studies were identified. The majority of these studies reported delayed onsets in muscle activation, differences in arm movement strategies, delayed movement timing, increased impact forces, and greater grasp errors in older compared to young adults. These differences were also identified under varied visual and cognitive conditions.

CONCLUSIONS

The studies included in this review demonstrate age-related differences in arm responses regardless of the direction and nature of the perturbation. These differences could provide insight into developing more targeted rehabilitation and fall prevention strategies. More research is needed to assess whether the identified age-related differences are a necessary compensation or a contributory factor to balance impairments and fall risk in older adults.

Protective arm movements are modulated with fall height

Protective arm reactions were evoked in 14 younger adults to determine the effect of fall height on protective arm reaction biomechanics. Participants were supported in a forward-leaning position on top of an inverted pendulum that isolated arm reaction by preventing any fall arresting contribution that may come from the ankle, knees, or hip. At an unpredictable time, the pendulum was released requiring participants to rapidly orient their arms to protect the head and body. Vertical ground reaction force (vGRF), arm kinematics, and electromyographic (EMG) measures of the biceps and triceps were compared at four initial lean angles. The time following perturbation onset and prior to impact consisted of two phases: rapid extension of the elbows and co-activation of the biceps and triceps in preparation for impact. The rapid orientation phase was modulated with fall height while the co-activation of the biceps and triceps in preparation for landing was minimally affected. Larger lean angles resulted in increased vGRF, increased elbow extension at impact, decreased elbow angular extension velocity at impact, and increased neck velocity at impact while hand velocity at impact was not significantly affected. The neuromuscular control strategy appears to optimize elbow extension angle/angular velocity prior to co-activation of the biceps and triceps that occurs about 100 ms prior to impact. Future work should investigate how the neuromuscular control strategy handles delayed deployment of protective arm reactions.

Ecology of falls

In this chapter, we consider how falls result from interactions between humans and their environment, and the implications of these interactions on the prevention of falls and fall-related injuries. We take a lifespan approach, and examine the human behaviors that create risk for falls and injuries in various environments, and the social and biologic factors that shape those behaviors. While not always stated explicitly, we draw on our experience in collecting and analyzing video footage of hundreds of falls. We consider that most falls do not result in significant injury, and issues of self-autonomy for pursuing a lifestyle that may create risk for falls. To help guide falls management, we propose a mechanism for classifying falls as "acceptable" versus "unacceptable." We also provide an ecology of falls checklist to guide stakeholders in identifying ecologic aspects of falls that may be useful targets for intervention.

Biomechanical and physiological age differences in a simulated forward fall on outstretched hands in women

BACKGROUND

Falling on the outstretched hands, a protective mechanism to arrest the body and avoid injury, requires upper limb and trunk motor control for effective body descent. Older women are particularly susceptible to injury from a forward fall, but the biomechanical and physiological (e.g., muscle strength) factors related to this increased risk are poorly understood. Determining age differences in the modifiable neuromuscular factors related to a forward fall landing and descent could help to inform injury prevention strategies. The purpose was to investigate age related differences in upper extremity strength and fall arrest strategy differences during a simulated fall and to evaluate the relationships between muscle strength and biomechanical variables.

METHODS

Nineteen younger (mean age 23.0 yrs., SD 3.8) and 16 older (mean age 68.2 yrs., SD 5.3) women performed five trials of simulated falls. Biomechanical measures and electromyographic muscle activity were recorded during the descents. Concentric, isometric and eccentric strength of the non-dominant upper limb was measured via a dynamometer using a customized protocol.

FINDINGS

Older women demonstrated lower concentric elbow extension strength compared to younger women (p = 0.002). Landing strategies differed where younger women had significantly greater elbow joint angle (p = 0.006) and velocity (p = 0.02) at impact. Older women demonstrated diminished capacity to absorb energy and control descent on outstretched hands compared to younger women (p = 0.001).

INTERPRETATION

The landing strategy used by older women along with decreased energy absorption may increase risk of fall-related injury and increase the likelihood of trunk or head impact with the ground.

The Tragically Hip: Trauma in Elderly Patients

Old age is a risk factor for poor outcome in trauma patients, as a result of undertriage and the presence of occult life-threatening injuries. The mechanisms of injury for geriatric trauma differ from those in younger patients, with a much higher incidence of low-impact trauma, especially falls from a low height. Frailty is a risk factor for severe injury after minor trauma, and caring for these patients require a multidisciplinary team with both trauma and geriatric expertise. With early recognition and aggressive management, severe injuries can still be associated with good outcomes, even in very elderly patients.

Does Fall Arrest Strategy Training Added to a Fall Prevention Programme Improve Balance, Strength, and Agility in Older Women? A Pilot Study

Purpose: The purpose of this study was to determine the effect of a unique exercise programme (Fall Arrest Strategy Training, or FAST) on upper body strength, range of motion (ROM), and fall risk in older women. FAST was designed to improve upper body capacity to prevent injury when a fall cannot be avoided. Method: A quasi-randomized site design included 71 older women (aged 67-95 y, mean age 83 years), who participated either in a standard fall prevention programme (Staying on Your Feet, or SOYF; n=29) or in SOYF combined with FAST (n=42). The women were measured three times-at baseline, after the 12-week intervention, and again 12 weeks later-for upper body strength, ROM, and fall risk factors (fall risk questionnaire, balance, mobility, and leg strength). Results: No significant differences were found in age, physical activity, or cognitive or functional status between the SOYF-standard and the SOYF-FAST groups. Both groups improved their fall risk status after the intervention, with no significant differences between them; however, the SOYF-FAST group showed greater improvements in upper extremity strength and ROM (p=0.007). Conclusion: FAST can feasibly be integrated into fall prevention programming, with additional gains in upper body strength and ROM in older women.

Female Age-Related Differences in Biomechanics and Muscle Activity During Descents on the Outstretched Arms

The purposes of this study were to examine female age differences in: (1) upper extremity (UE) and trunk muscle activity, elbow joint moment, loading force, and UE energy absorption during a controlled forward body descent; and (2) UE muscle strength. Twenty young (mean 24.8 ± 3.4 years) and 20 older (68.4 ± 5.7 years) women were assessed via dynamometry for isometric, concentric, and eccentric UE strength and performed forward descents on force plates at three body lean angles (60°, 45°, and 30° from horizontal). Significant differences (p < .05) were found for muscle strength, biomechanics, and muscle activity. Concentric UE strength averaged 15% lower in older women. At 30° body lean, older women absorbed less energy. Older women had greater biceps brachii activation and less external oblique activation at all body lean angles. Age differences in muscle strength, activation, and energy absorption may contribute to fall-related injury risk.

Correlation between obesity and severity of distal radius fractures

INTRODUCTION

The incidence of obesity has increased significantly worldwide. Our hypothesis was that patients with obesity have a more severe distal radius fracture and we realized a study to evaluate this correlation between obesity and severity of distal radius fractures caused by low-energy injuries.

MATERIALS AND METHODS

A total of 114 patients with distal radius fracture were examined in a cross-sectional, observational study. Fractures were classified according to the international AO-Müller/Orthopedic Trauma Association (AO/OTA) classification in order to determine the severity. The patient's Body Mass Index (BMI) was calculated and a Pearson correlation was performed.

RESULTS

The patients were predominantly female, and left side was more frequently affected. Most of the fractures were AO/OTA type A (71 patients). The majority of the involved patients in our study were overweighed or obese. We do not observe a direct correlation between grade of obesity and distal radius fracture severity.

CONCLUSIONS

Based on the results of this study obesity and severity of distal radius fractures do not correlate.

LEVEL OF EVIDENCE

Prognostic. Level IV.

Falls and Wrist Fracture: Relationship to Women's Functional Status after Age 50

Women experience a rapid rise in the incidence of wrist fracture after age 50. Accordingly, this study aimed to (1) determine the internal and environmental fall-related circumstances resulting in a wrist fracture, and (2) examine the relationship of functional status to these circumstances. Women aged 50 to 94 years reported on the nature of the injury (n = 99) and underwent testing for physical activity status, balance, strength, and mobility (n = 72). The majority of falls causing wrist fracture occurred outdoors, during winter months, as a result of a slip or trip while walking. Half of these falls resulted in other injuries including head, neck, and spine injuries. Faster walking speed, lower grip strength, and higher balance confidence were significantly associated with outdoor versus indoor falls and slips and trips versus other causes. This study provides insights into potential screening and preventive measures for fall-related wrist fractures in women.

Risk factors for hip impact during real-life falls captured on video in long-term care

Hip fracture risk is increased by landing on the hip. We examined factors that contribute to hip impact during real-life falls in long-term care facilities. Our results indicate that hip impact is equally likely in falls initially directed forward as sideways and more common among individuals with dependent Activities of Daily Living (ADL) performance.

INTRODUCTION

The risk for hip fracture in older adults increases 30-fold by impacting the hip during a fall. This study examined biomechanical and health status factors that contribute to hip impact through the analysis of real-life falls captured on video in long-term care (LTC) facilities.

METHODS

Over a 7-year period, we captured 520 falls experienced by 160 residents who provided consent for releasing their health records. Each video was analyzed by a three-member team using a validated questionnaire to determine whether impact occurred to the hip or hand, the initial fall direction and landing configuration, attempts of stepping responses, and use of mobility aids. We also collected information related to resident physical and cognitive function, disease diagnoses, and use of medications from the Minimum Data Set.

RESULTS

Hip impact occurred in 40 % of falls. Falling forward or sideways was significantly associated with higher odds of hip impact, compared to falling backward (OR 4.2, 95 % CI 2.4-7.1) and straight down (7.9, 4.1-15.6). In 32 % of sideways falls, individuals rotated to land backward. This substantially reduced the odds for hip impact (0.1, 0.03-0.4). Tendency for body rotation was decreased for individuals with dependent ADL performance (0.43, 0.2-1.0).

CONCLUSIONS

Hip impact was equally likely in falls initially directed forward as sideways, due to the tendency for axial body rotation during descent. A rotation from sideways to backward decreased the odds of hip impact 10-fold. Our results may contribute to improvements in risk assessment and strategies to reduce risk for hip fracture in older adults.

Bone strength and muscle properties in postmenopausal women with and without a recent distal radius fracture

Distal radius (wrist) fracture (DRF) in women over age 50 years is an early sign of bone fragility. Women with a recent DRF compared to women without DRF demonstrated lower bone strength, muscle density, and strength, but no difference in dual-energy x-ray absorptiometry (DXA) measures, suggesting DXA alone may not be a sufficient predictor for DRF risk.

INTRODUCTION

The objective of this study was to investigate differences in bone and muscle properties between women with and without a recent DRF.

METHODS

One hundred sixty-six postmenopausal women (50-78 years) were recruited. Participants were excluded if they had taken bone-altering medications in the past 6 months or had medical conditions that severely affected daily living or the upper extremity. Seventy-seven age-matched women with a fracture in the past 6-24 months (Fx, n = 32) and without fracture (NFx, n = 45) were measured for bone and muscle properties using the nondominant (NFx) or non-fractured limb (Fx). Peripheral quantitative computed tomography (pQCT) was used to estimate bone strength in compression (BSIc) at the distal radius and tibia, bone strength in torsion (SSIp) at the shaft sites, muscle density, and area at the forearm and lower leg. Areal bone mineral density at the ultradistal forearm, spine, and femoral neck was measured by DXA. Grip strength and the 30-s chair stand test were used as estimates of upper and lower extremity muscle strength. Limb-specific between-group differences were compared using multivariate analysis of variance (MANOVA).

RESULTS

There was a significant group difference (p < 0.05) for the forearm and lower leg, with the Fx group demonstrating 16 and 19% lower BSIc, 3 and 6% lower muscle density, and 20 and 21% lower muscle strength at the upper and lower extremities, respectively. There were no differences between groups for DXA measures.

CONCLUSIONS

Women with recent DRF had lower pQCT-derived estimated bone strength at the distal radius and tibia and lower muscle density and strength at both extremities.

Contact areas of the scaphoid and lunate with the distal radius in neutral and extension: correlation of falling strategies and distal radial anatomy

The functional neutral of wrist movement is about 10° extension yet the distal radius has a volar tilt. This has not previously been explained. Assuming that the contact area between the carpus and the distal radius increased in wrist extension this would also help stabilize the carpus on the distal radius in positions where typically there is greater loading. To test this hypothesis we reconstructed three-dimensional structures of the carpal bones and distal radius using computed tomography scans of 13 normal wrists. The contact areas of the scaphoid with the distal radius were measured and were found progressively increased from flexion 20°, neutral, extension 20°, to extension 40°. The maximal increases in the contact area of the scaphoid and the distal radius was at full wrist extension. No significant changes in the contact areas of the lunate with the distal radius were found between the different positions. The contact characteristics provide greater stability to the carpus on the distal radius, and to help spread forces from impact to the wrist reducing the transmitted peak forces and thus the risk of distal radius and carpal injuries.

Autonomy, choice, patient-centered care, and hip protectors: the experience of residents and staff in long-term care

The purpose of this study was to examine long-term care (LTC) resident and staff perceptions on the decision to use hip protectors and identify the factors that influence attitudes toward hip protector use. Staff (N = 39) and residents (N = 27) at two residential care facilities in British Columbia, Canada were invited to participate in focus groups on fall prevention and hip protector use. A total of 11 focus groups were conducted. Using framework analysis results show that residents and staff shared concerns on aesthetic and comfort issues with hip protectors. Residents also generally felt they did not need, or want to use, hip protectors. However, they also had desire to be cooperative within the LTC environment. Staff underscored their role in advocating for hip protector use and their desire to protect residents from harm. Practice considerations for facilities wishing to promote hip protectors within a patient centered framework are highlighted.

Prevalence of and factors associated with head impact during falls in older adults in long-term care

BACKGROUND

Falls cause more than 60% of head injuries in older adults. Lack of objective evidence on the circumstances of these events is a barrier to prevention. We analyzed video footage to determine the frequency of and risk factors for head impact during falls in older adults in 2 long-term care facilities.

METHODS

Over 39 months, we captured on video 227 falls involving 133 residents. We used a validated questionnaire to analyze the mechanisms of each fall. We then examined whether the probability for head impact was associated with upper-limb protective responses (hand impact) and fall direction.

RESULTS

Head impact occurred in 37% of falls, usually onto a vinyl or linoleum floor. Hand impact occurred in 74% of falls but had no significant effect on the probability of head impact (p = 0.3). An increased probability of head impact was associated with a forward initial fall direction, compared with backward falls (odds ratio [OR] 2.7, 95% confidence interval [CI] 1.3-5.9) or sideways falls (OR 2.8, 95% CI 1.2-6.3). In 36% of sideways falls, residents rotated to land backwards, which reduced the probability of head impact (OR 0.2, 95% CI 0.04-0.8).

INTERPRETATION

Head impact was common in observed falls in older adults living in long-term care facilities, particularly in forward falls. Backward rotation during descent appeared to be protective, but hand impact was not. Attention to upper-limb strength and teaching rotational falling techniques (as in martial arts training) may reduce fall-related head injuries in older adults.

Fall-related fracture trends among elderly in Sweden--exoring transitions among hospitalized cases

PROBLEM

Fall-related injuries have been a cause of worry during the end of the 20th century with increasing trends among the elderly.

METHOD

Using data from the Swedish National Patient Register (NPR) based on hospital admissions, this study explores the trends in fall-related fractures between 1998 and 2010.

RESULTS

The data shows a decreasing trend in fall-related fractures in all age- and sex-specific groups apart from men 80 years and above. While hip fracture incidence rates decreased in all age- and sex-specific groups, both central fractures and upper extremity fractures have increased in all age- and sex-specific groups apart from women 65-79 years. Lower extremity fractures have increased in the older age groups and decreased in the younger.

DISCUSSION

The differences found between the groups of fractures and by age- and sex-specific groups indicate a possible transition where more serious fractures are decreasing while less serious fractures increase among hospitalized cases.

SUMMARY

Perhaps due to a focus on hip fracture prevention, this study shows that while the incidence rate of hospitalized hip fractures has decreased, other fall-related hospitalized fractures have increased.

IMPACT ON INDUSTRY

Potentially, this could be indicative of a healthier younger elderly, coupled with a frailer older elderly requiring more comprehensive healthcare also for less serious injuries. Further research is needed to confirm our results.