Yi-Jian Yang

Prof. Yi-Jian Yang

The Chinese University of Hong Kong
orcid

Research Focus & Metrics

Academic Career Length

17Years (2010-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 January 2013 in The Lancet
Verified
Journal Article
Closed access
SRStephen N Robinovitch
Stephen N Robinovitch
FFFabio Feldman
Fabio Feldman
Yi-Jian YangYi-Jian Yang
Yi-Jian Yang
RSRebecca Schonnop
Rebecca Schonnop
PLPet Ming Leung
Pet Ming Leung
MLMarie Loughin
Marie Loughin

13 May 2020 in Journal of Bone and Mineral Research
Verified
Journal Article
Open access
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Yi-Jian YangYi-Jian Yang
Yi-Jian Yang
VKVicki Komisar
Vicki Komisar
NSNataliya Shishov
Nataliya Shishov
BLBryan Lo
Bryan Lo
AKAlexandra Mb Korall
Alexandra Mb Korall
SRStephen N Robinovitch
Stephen N Robinovitch
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.

7 October 2013 in Canadian Medical Association Journal
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Journal Article
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RSRebecca Schonnop
Rebecca Schonnop
Yi-Jian YangYi-Jian Yang
Yi-Jian Yang
FFFabio Feldman
Fabio Feldman
ERErin Robinson
Erin Robinson
MLMarie Loughin
Marie Loughin
SRStephen N. Robinovitch
Stephen N. Robinovitch
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.

13 March 2019 in BMC Geriatrics
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Journal Article
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BSBrett H. Shaw
Brett H. Shaw
DBDave Borrel
Dave Borrel
KSKimiya Sabbaghan
Kimiya Sabbaghan
CKColton Kum
Colton Kum
Yi-Jian YangYi-Jian Yang
Yi-Jian Yang
VCVictoria E. Claydon
Victoria E. Claydon
Orthostatic hypotension (OH; profound falls in blood pressure when upright) is a common deficit that increases in incidence with age, and may be associated with falling risk. Deficit accumulation results in frailty, regarded as enhanced vulnerability to adverse outcomes. We aimed to evaluate the relationships between OH, frailty, falling and mortality in elderly care home residents. From the Minimum Data Set (MDS) document, a frailty index (FI-MDS) was generated from a list of 58 deficits, ranging from 0 (no deficits) to 1.0 (58 deficits). OH was evaluated from beat-to-beat blood pressure and heart rate (finger plethysmography) collected during a 15-min supine-seated orthostatic stress test. Retrospective and prospective falling rates (falls/year) were extracted from facility falls incident reports. All-cause 3-year mortality was determined. Data are reported as mean ± standard error. Data were obtained from 116 older adults (aged 84.2 ± 0.9 years; 44% males) living in two long term care facilities. The mean FI-MDS was 0.36 ± 0.01; FI-MDS was correlated with age (r = 0.277; p = 0.003). Those who were frail (FI ≥ 0.27) had larger Initial (− 17.8 ± 4.2 vs − 6.1 ± 3.3 mmHg, p = 0.03) and Consensus (− 22.7 ± 4.3 vs − 11.5 ± 3.3 mmHg, p = 0.04) orthostatic reductions in systolic arterial pressure. Frail individuals had higher prospective and retrospective falling rates and higher 3-year mortality. Receiver operating characteristic curves evaluated the ability of FI-MDS alone to predict prospective falls (sensitivity 72%, specificity 36%), Consensus OH (sensitivity 68%, specificity 60%) and 3-year mortality (sensitivity 77%, specificity 49%). Kaplan Meier survival analyses showed significantly higher 3-year mortality in those who were frail compared to the non-frail (p = 0.005). Frailty can be captured using a frailty index based on MDS data in elderly individuals living in long term care, and is related to susceptibility to orthostatic hypotension, falling risk and 3-year mortality. Use of the MDS to generate a frailty index may represent a simple and convenient risk assessment tool for older adults living in long term care. Older adults who are both frail and have impaired orthostatic blood pressure control have a particularly high risk of falling and should receive tailored management to mitigate this risk.

Wilson LeungWilson Leung
Wilson Leung
Raymond SumRaymond Sum
Raymond Sum
Yi-Jian YangYi-Jian Yang
Yi-Jian Yang
Understanding the sedentary patterns can guide the design of strategies to engage older adults in physical activity. This scoping review aimed to synthesize available evidence on sedentary behaviors in care facilities. We searched PubMed/MEDLINE and Web of Science for studies published from inception through October 2020. Eighteen studies were included and reviewed according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. Data obtained were analyzed based on levels of care provided. Overall, daily sedentary time was higher among residents in high level care facilities (e.g., nursing homes) (11.6 h/day) than intermediate/mixed level care facilities (e.g., assisted living) (9.5 h/day). In intermediate/mixed level care facilities, television (TV) viewing was the most common sedentary activity (2.5–2.9 h/day; 26% of daily sedentary time), while napping was the most favorite sedentary activity (4.7 h/day; 36% of waking hours) in high level care facilities. Sex differences in daily patterns of sedentary behavior (sedentary time, uninterrupted bouts, and bout durations) were commonly observed in intermediate/mixed level care facilities, as exemplified by men being more sedentary by 0.7–1.1 h/day. In summary, this study highlights distinctive sedentary patterns among older adults residing in different levels of care facilities, addressing a pressing need for customized interventions to engage care facility residents in physical activity.

19 April 2022 in BMC Geriatrics
Verified
Journal Article
Open access
PDF file
VKVicki Komisar
Vicki Komisar
ADAleksandra Dojnov
Aleksandra Dojnov
Yi-Jian YangYi-Jian Yang
Yi-Jian Yang
NSNataliya Shishov
Nataliya Shishov
HCHelen Chong
Helen Chong
SRStephen N. Robinovitch
Stephen N. Robinovitch
Background: Falls are the leading cause of injuries in older adults. However, most falls in older adults do not cause serious injury, suggesting that older adults may fall in a manner that reduces the likelihood of impact to body sites that are most vulnerable to injury. In this observational study of falls in long-term care (LTC), we tested whether body parts differed in their probability of impact and injury. Methods: We recorded and analyzed videos of 2388 falls by 658 LTC residents (mean age 84.0 (SD = 8.1); 56.4% female). We used Linear Mixed Models to test for differences between body parts in the probability of impact and injury, and injury when impacts occurred. Results: Injuries were reported in 38.2% of falls, and 85.9% of injuries involved direct impact to the injured body part. Impact occurred most often to the hip/pelvis (probability (standard error) = 0.95 (0.01); p < .001 relative to other body parts), and least often to the head (0.35 (0.01)). Conversely, injury occurred most often to the head (p < .001 relative to other body parts). The probability of injury when impacts occurred was 0.40 (0.01) for the head, and 0.11 or less for all other body parts. Conclusion: Our results help to explain why most falls by older adults in LTC do not cause serious injury: residents land on body parts that are the most resilient to injury. The high susceptibility of the head to injury reinforces the need to enhance upper limb protective responses for fall arrest. The dominant role of direct impact as the mechanism of injury supports approaches to attenuate impact forces through strategies like protective clothing and compliant flooring.