***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    Input: The purpose of this in vitro biomechanical study is to determine the force attenuation capacity of four different hip protectors ( KPH1 , KPH2 , Safehip , and Safetypants ) in falling simulations in elderly subjects ( falls to the side ) . The simulated falling conditions were created by a biomechanical testing system , which consisted of an impact pendulum , surrogate pelvis and femur , and two load cells . Three series of impact experiments were conducted in an ascending order ( low , moderate- , and high-force experiments ) , each exceeding the literature -provided average ( + /- 1 SD ) fracture threshold ( 3100 + /- 1200 N ) of the proximal femur of elderly women with a mean age of 71 years . Using a low impact force of 4330 N , the trochanteric soft tissue ( 20-mm-thick polyethylene foam ) attenuated the peak femoral impact force to 3740 N and , accordingly , the KPH1 protector to 590 N , KPH2 to 510 N , Safehip to 1080 N , and Safetypants to 790 N. Thus , in this low force experiment , all tested protectors could reduce the peak impact force entered into the proximal femur below the aforementioned average fracture threshold area ( 3100 + /-1200 N ) of the proximal femur of elderly women . With a moderate impact force of 7230 N , the soft tissue attenuated the peak femoral impact force to 6130 N , and the protectors to 780 N , 760 N , 2240 N , and 2760 N , respectively . Thus , with this impact force , only the KPH hip protectors could reduce the impact force clearly below the fracture threshold area . In the final series of the experiment , the peak femoral impact force was set to be so high ( 10,840 N ) that the protector , if effective , should prevent the hip fracture in almost all cases and situations . The trochanteric soft tissue attenuated this peak impact force to 9190 N , and the tested protectors to 1360 N , 1170 N , 4640 N , and 5770 N. Thus , with the KPH protectors the force received by the proximal femur remained below the average force required to fracture the proximal femur of elderly women , whereas with the two other protectors the impact force entered into the proximal femur clearly exceeded this threshold value . In conclusion , the test results showed that , of the four tested hip protectors , the anatomically design ed energy-shunting and energy-absorbing KPH protectors can provide an effective impact force attenuation in a sideways-fall simulation in the elderly , whereas the force attenuation capacity of the two other protectors seems more limited . However , the true efficacy of any protector in the prevention of hip fractures can only be evaluated in r and omized clinical trials R and omized trials in which the unit of r and omization is a community , worksite , school or family are becoming widely used in the evaluation of life-style interventions for the prevention of disease . The increasing interest in adopting a cluster r and omization design is being matched by rapid method ological developments . In this paper we describe several of these developments . Brief mention is also made of issues related to economic analysis and to the planning and conduct of meta-analyses for cluster r and omization trials . Recommendations for reporting are also discussed OBJECTIVES To investigate the effect of use of external hip protectors on occurrence of  hip fracture . DESIGN R and omized controlled trial , with r and omization at the individual level . SETTING residential aged-care facilities in urban areas of New South Wales , Australia . PARTICIPANTS 174 women , aged 75 years and older , who had had two or more falls or one fall requiring hospital admission in the previous 3 months , and who lived in hostels or nursing homes . Eighty-six subjects were in the intervention group and 88 in the control group . INTERVENTION Use of external hip protectors and encouragement by nurses to use the protectors . MEASUREMENTS Follow-up visits at approximately 2 weeks and 2 , 10 and 18 months to determine falls and fall injury ( including hip fracture ) ; we also measured adherence to hip protector use . RESULTS The mean age of participants was 85 ; they lived in 32 different aged-care facilities , two-thirds of which were nursing homes . Intervention and control groups had similar baseline characteristics , with a mean Barthel index of 58 at enrollment and a mean Short Portable Mental Status Question naire score of six errors , indicating severe disability and major cognitive impairment . During follow-up , a mean of 4.6 falls per person occurred . There was no difference in mortality , with 28 deaths in each group . Eight hip fractures occurred in the intervention group and seven in the control group ( hazard ratio 1.46 ; 95 % confidence interval 0.53 - 4.51 ) . No hip fractures occurred when hip protectors were being worn as directed . Adherence was about 57 % over the duration of the study and hip protectors were worn at the time of 54 % of falls in the intervention group . Adherence varied markedly between institutions , but the greatest was about 80 % . CONCLUSION Hip protectors were not effective in reducing the incidence of hip fractures in this study , but because of low statistical power , a reduction in risk of hip fracture of up to 50 % may not have been detected . There was limited adherence with their use , result ing in a large number of falls occurring without hip protectors in place . All hip fractures in the intervention group occurred when hip protectors were not being used Abstract : A method to protect the hips during falls could effectively reduce the incidence of  hip fractures . We report the results of the first hip protector  trial in Japan , performed between July 1996 , and September 1999 . One hundred and sixty-four elderly female residents of nursing homes , with Activities of Daily Living above the wheelchair level , agreed to participate in this study . Among them , 88 were r and omly selected to wear a hip protector and 76 controls did not .  All falls and result ing injuries were recorded daily . In anthropometric measurements and ultrasonic bone evaluation , no significant differences were found between the two groups , except in height . During an average of 377 days , the wearers and the non-wearers fell a total of 131 and 90 times , respectively . Among the wearers , there were two non-hip fractures and one hip fracture , so the annual hip fracture rate was calculated at 1.2 % , against 8 hip fractures among the non-wearers , or 9.7 % per year . The hip fracture rate was significantly lower among the wearers than non-wearers , while the annual number of falls per subject and the distribution of fallers remained the same . According to Cox ’s proportional hazard regression analysis , the effect of the hip protector on hip fracture prevention was independent of anthropometric data , ultrasonic bone assessment values or number of falls . Moreover , even after limiting the subjects to fallers only , the annual hip fracture rate in non-wearers was higher than in wearers ( 19.8 % vs 2.0 % ) and the annual hip fracture rate per fall in wearers was lower than that in non-wearers ( 0.8 % vs 8.2 % ) . It was thus concluded that the hip protector is a beneficial device for the prevention of hip fractures OBJECTIVES To evaluate the effectiveness of a multifaceted , nonpharmaceutical intervention on incidence of falls and fallers . DESIGN Prospect i ve , cluster-r and omized , controlled 12-month trial . SETTING Six community nursing homes in Germany . PARTICIPANTS Long-stay residents ( n = 981 ) aged 60 and older ; mean age 85 ; 79 % female . INTERVENTIONS Staff and resident education on fall prevention , advice on environmental adaptations , progressive balance and resistance training , and hip protectors . MEASUREMENTS Falls , fallers , and fractures . RESULTS The incidence density rate of falls per 1,000 resident years ( RY ) was 2,558 for the control group ( CG ) and 1,399 for the intervention group ( IG ) ( relative risk ( RR ) = 0.55 , 95 % confidence interval ( CI ) = 0.41 - 0.73 ) . Two hundred forty-seven ( 52.3 % ) fallers were detected in the CG and 188 ( 36.9 % ) in the IG ( RR = 0.75 , 95 % CI = 0.57 - 0.98 ) . The incidence density rate of frequent fallers ( > 2/year ) was 115 ( 24.4 % ) for the CG and 66 ( 13.0 % ) for the IG ( RR = 0.56 , 95 % CI = 0.35 - 0.89 ) . The incidence density rate of hip fractures per 1,000 RY was 39 for the CG and 43 for the IG ( RR = 1.11 , 95 % CI = 0.49 - 2.51 ) . Other fractures were diagnosed with an incidence density rate of 52 per 1,000 RY for CG and 41 per 1,000 RY for IG ( RR = 0.78 , 95 % CI = 0.57 - 1.07 ) . CONCLUSION The incidence density rate of falls and fallers differed considerably between the control and intervention groups . The study was underpowered to demonstrate a significant difference of hip or nonhip fractures . Because of a low fracture rate in both groups , the investigation of fracture rates would have required a larger sample size to detect an effect of the intervention CONTEXT Several r and omized controlled trials have been performed to examine the effectiveness of external hip protectors in reducing the incidence of hip fractures , but the results are controversial . OBJECTIVE To examine the effectiveness of hip protectors in reducing the incidence of hip fractures in an elderly high-risk population . DESIGN , SETTING , AND PARTICIPANTS R and omized controlled trial of elderly persons aged 70 years or older , who have low bone density , and are at high risk for falls . Participants lived in apartment houses for the elderly , homes for the elderly , and nursing homes in Amsterdam and surrounding areas in the Netherl and s. They were enrolled in the study between March 1999 and March 2001 ; the mean follow-up was 69.6 weeks . Of the 830 persons who were screened , 561 persons were enrolled . INTERVENTION External hip protector . Both groups received written information on bone health and risk factors for falls . MAIN OUTCOME MEASURE Time to first hip fracture . Survival analysis was used to include all participants for the time they participated . RESULTS In the intervention group , 18 hip fractures  occurred vs 20 in the control group . Four hip fractures in the intervention group occurred while an individual was wearing a hip protector . At least 4 hip fractures in the intervention group occurred late at night or early in the morning . Both in univariate analysis ( log-rank P = .86 ) and in multivariate analysis ( hazard ratio [ HR ] , 1.05 ; 95 % confidence interval [ CI ] , 0.55 - 2.03 ) , no statistically significant difference between the intervention group and control group was found with regard to time to first hip fracture . In addition , the per protocol analysis in compliant participants did not show a statistically significant difference between the groups ( HR , 0.77 ; 95 % CI , 0.25 - 2.38 ) . CONCLUSION The hip protector studied was not effective in preventing hip fractures Abstract :  Hip fracture  is associated with a higher mortality rate in men than in women . However , mean age of men and women with hip fracture differs markedly . Thus , some of the differences in the clinical pattern and outcome between genders could be related to different ages . To avoid the influence of age on gender-specific outcome , we analyzed prefracture conditions and hip fracture outcome in a cohort of men and of age-matched women . Risk factors for low bone mass were recorded in 106 men ( mean age ± SD , 80.3 ± 9.3 years ) and 264 age-matched women ( mean age 81.4 ± 8.0 ) with hip fracture . We compared mortality rate , survival , years of potential life lost and modification of housing conditions . These outcomes were prospect ively assessed during an average 3.6 years follow-up ( up to 7 years ) . Men with hip fracture differed from age-matched hip-fractured women by a higher alcohol and tobacco consumption , a greater frequency of living in couple , and by less prevalent fractures . Mortality rate after hip fracture was significantly higher in men ( RR = 1.74 , 95 % CI 1.34–2.24 ) . Since mortality is higher in the general male population , we compared reduction in life expectancy taking into account the gender-specific mortality rate . The excess mortality in each age-group of hip-fractured patients , which was measured during the whole follow-up period , and is an estimate of death attributable to fracture , did not differ between genders . Reduction in life expectancy due to hip fracture was similar in both genders ( 5.9 ± 4.5 and 5.8 ± 4.8 years , in men and women , respectively ; NS ) , but the proportion of the years of life lost was higher in men ( 70 ± 33 % ) than in women ( 59 ± 42 % , p < 0.01 ) . It was concluded that for the same age , mortality rate after hip fracture was higher in men than in women . Although the reduction in life expectancy was similar in both genders , the 
    Output:
    
Thus , there is little evidence to support the use of hip protectors outside the nursing home setting .