B.E. Groen

Efficacy of a Short Multidisciplinary Falls Prevention Program for Elderly Persons With Osteoporosis and a Fall History: A Randomized Controlled Trial

OBJECTIVE To evaluate the efficacy of the Nijmegen Falls Prevention Program (NFPP) for persons with osteoporosis and a fall history in a randomized controlled trial. Persons with osteoporosis are at risk for fall-related fractures because of decreased bone strength. A decrease in the number of falls therefore is expected to be particularly beneficial for these persons. DESIGN Randomized controlled trial. SETTING Hospital. PARTICIPANTS Persons with osteoporosis and a fall history (N=96; mean ± SD age, 71.0±4.7y; 90 women). INTERVENTION After baseline assessment, participants were randomly assigned to the exercise (n=50; participated in the NFPP for persons with osteoporosis [5.5wk]) or control group (n=46; usual care). MAIN OUTCOME MEASURES Primary outcome measure was fall rate, measured by using monthly fall calendars for 1 year. Secondary outcomes were balance confidence (Activity-specific Balance Confidence Scale), quality of life (QOL; Quality of Life Questionnaire of the European Foundation for Osteoporosis), and activity level (LASA Physical Activity Questionnaire, pedometer), assessed posttreatment subsequent to the program and after 1 year of follow-up. RESULTS The fall rate in the exercise group was 39% lower than for the control group (.72 vs 1.18 falls/person-year; risk ratio, .61; 95% confidence interval, .40-.94). Balance confidence in the exercise group increased by 13.9% (P=.001). No group differences were observed in QOL and activity levels. CONCLUSION The NFPP for persons with osteoporosis was effective in decreasing the number of falls and improving balance confidence. Therefore, it is a valuable new tool to improve mobility and independence of persons with osteoporosis.

Sensitivity of the OLGA and VCM models to erroneous marker placement: Effects on 3D-gait kinematics

Gait data need to be reliable to be valuable for clinical decision-making. To reduce the impact of marker placement errors, the Optimized Lower Limb Gait Analysis (OLGA) model was developed. The purpose of this study was to assess the sensitivity of the kinematic gait data to a standard marker displacement of the OLGA model compared with the standard Vicon Clinical Manager (VCM) model and to determine whether OLGA reduces the errors due to the most critical marker displacements. Healthy adults performed six gait sessions. The first session was a standard gait session. For the following sessions, 10mm marker displacements were applied. Kinematic data were collected for both models. The root mean squares of the differences (RMS) were calculated for the kinematics of the displacement sessions with respect to the first session. The results showed that the RMS values were generally larger than the stride-to-stride variation except for the pelvic kinematics. For the ankle, knee and hip kinematics, OLGA significantly reduced the averaged RMS values for most planes. The shank, knee and thigh anterior-posterior marker displacements resulted in RMS values exceeding 10°. OLGA reduced the errors due to the knee and thigh marker displacements, but not the errors due to the ankle marker displacements. In conclusion, OLGA reduces the effect of erroneous marker placement, but does not fully compensate all effects, indicating that accurate marker placement remains of crucial importance for adequate 3D-gait analysis and subsequent clinical decision-making.

Could martial arts fall training be safe for persons with osteoporosis?: a feasibility study

BackgroundOsteoporosis is a well-established risk factor for fall-related hip fractures. Training fall arrest strategies, such as martial arts (MA) fall techniques, might be useful to prevent hip fractures in persons with osteoporosis, provided that the training itself is safe. This study was conducted to determine whether MA fall training would be safe for persons with osteoporosis extrapolated from the data of young adults and using stringent safety criteria.MethodsYoung adults performed sideways and forward MA falls from a kneeling position on both a judo mat and a mattress as well as from a standing position on a mattress. Hip impact forces and kinematic data were collected. For each condition, the highest hip impact force was compared with two safety criteria based on the femoral fracture load and the use of a hip protector.ResultsThe highest hip impact force during the various fall conditions ranged between 1426 N and 3132 N. Sideways falls from a kneeling and standing position met the safety criteria if performed on the mattress (max 1426 N and 2012 N, respectively) but not if the falls from a kneeling position were performed on the judo mat (max 2219 N). Forward falls only met the safety criteria if performed from a kneeling position on the mattress (max 2006 N). Hence, forward falls from kneeling position on a judo mat (max 2474 N) and forward falls from standing position on the mattress (max 3132 N) did not meet both safety criteria.ConclusionsBased on the data of young adults and safety criteria, the MA fall training was expected to be safe for persons with osteoporosis if appropriate safety measures are taken: during the training persons with osteoporosis should wear hip protectors that could attenuate the maximum hip impact force by at least 65%, perform the fall exercises on a thick mattress, and avoid forward fall exercises from a standing position. Hence, a modified MA fall training might be useful to reduce hip fracture risk in persons with osteoporosis.

The effects of time pressure and experience on the performance of fall techniques during a fall.

Although the practice of fall techniques has been introduced in fall prevention programs, it is not clear whether people can apply acquired techniques during a real-life fall. It would be helpful to know the time it takes to initiate and to successfully execute such techniques, as well as the effect of experience on the execution of these techniques. In this study we investigated the neuromuscular control of voluntary fall techniques in five seasoned judokas and nine non-judokas. After they had started falling from a kneeling position, they received an auditory cue prompting either a lateral natural fall arrest (block) or a martial arts (MA) fall. EMG data of shoulder and trunk muscles were collected. The requested technique was successfully applied in 85% of the falls. Following the cue, EMG amplitudes of the fall techniques started to diverge after 180-190 ms. EMG amplitudes were generally similar in both groups, but experience-related differences could be demonstrated in the pectoralis and trapezius. In conclusion, voluntary motor control is possible within the duration of a fall, even in inexperienced fallers. Differences in EMG activity might suggest that experienced fallers changed their reaction to possible falls from a preparation for arm abduction into a preparation for trunk rotation.

Construct Validity of the Trunk Impairment Classification System in Relation to Objective Measures of Trunk Impairment

OBJECTIVE To determine the validity of the Trunk Impairment Classification system (TIC) with 4 possible scores (0, most impaired; 0.5; 1.0; 1.5, least impaired) in relation to objective, instrumented measures of impairment. DESIGN Cross-sectional design. SETTING National wheelchair rugby and basketball competitions of The Netherlands and Belgium. PARTICIPANTS Volunteer sample of athletes (N=34) with a minimum of 1-year experience in their sport. INTERVENTIONS Static sitting balance tasks on a stable and unstable surface; dynamic sitting balance tasks in anterior-posterior, left-right, and oblique directions; and trunk muscle strength tasks in forward, left, right, and backward directions. MAIN OUTCOME MEASURES Sway area of the center of pressure in static sitting balance, maximum excursion of center of pressure displacement in dynamic sitting balance, and maximum isometric force in trunk muscle strength. RESULTS Athletes with TIC score 0 were not able to sit unsupported. The Kruskal-Wallis test showed a significant difference in trunk muscle strength (P<.001) and dynamic balance in the oblique direction forward to the left and backward to the right between the TIC scores (P=.012). Post hoc analysis showed a significant difference between TIC score 0 and the other TIC scores for trunk muscle strength in all directions. There was a significant difference between TIC score 1.5 on one hand and TIC scores 0.5 and 1.0 on the other hand for dynamic balance in the right oblique direction. CONCLUSIONS The TIC is a valid scale for trunk impairment, which measures neuromusculoskeletal trunk impairment, independent of the health condition causing the impairment. Additional research is needed for coordination impairment and to assess whether TIC scores 0.5 and 1.0 should continue as separate scores.

Classifying trunk strength impairment according to the activity limitation caused in wheelchair rugby performance

International Federations in Paralympic sports should develop evidence‐based classification, based on the relative strength of association between impairment and activities that determine sport‐specific performance. The purpose of the current study was to assess the relationship between trunk strength impairment and three activities that determine performance in wheelchair rugby, and to determine whether this relationship supports the concept of “natural classes.” Trunk muscle strength and three determinants of performance were assessed in 27 athletes. The correlations between lateral trunk muscle strength and the determinant tilting the chair, and between forward trunk muscle strength and the determinants 1 m acceleration and sprint momentum were calculated. To group athletes based on impairment, K‐means cluster analysis was used to group athletes according to how much trunk muscle strength affected the activities. There were significant, moderate to strong correlations between left‐right strength and chair tilting (r=.50), between forward strength and 1 m acceleration (r=.59), and between forward strength and sprint momentum (r=.79). Cluster analysis indicated at least one cut‐point in performance with a decrease in impairment in all three wheelchair activities, supporting the concept of “natural classes.”

Martial arts fall techniques reduce hip impact forces in naive subjects after a brief period of training

Hip fractures are among the most serious consequences of falls in the elderly. Martial arts (MA) fall techniques may reduce hip fracture risk, as they are known to reduce hip impact forces by 30% in experienced fallers. The purpose of this study was to investigate whether hip impact forces and velocities in MA falls would be smaller than in a ‘natural’ fall arrest strategy (Block) in young adults (without any prior experience) after a 30-min training session in sideways MA fall techniques. Ten subjects fell sideways from kneeling height. In order to identify experience-related differences, additional EMG data of both fall types were collected in inexperienced (n = 10) and experienced fallers (n = 5). Compared to Block falls, MA falls had significantly smaller hip impact forces ( 17%) and velocities ( 7%). EMG results revealed experience-related differences in the execution of the MA fall, indicative of less pronounced trunk rotation in the inexperienced fallers. This may explain their smaller reduction of impact forces compared to experienced fallers. In conclusion, the finding that a substantial reduction in impact forces can be achieved after a short training in MA techniques is very promising with respect to their use in interventions to prevent fall injuries. 2007 Elsevier Ltd. All rights reserved.