Predicting falls in older adults using the four square step test

The Four Square Step Test (FSST) is a performance-based balance tool involving stepping over four single-point canes placed on the floor in a cross configuration. The purpose of this study was to evaluate properties of the FSST in older adults who lived independently. Forty-five community dwelling older adults provided fall history and completed the FSST, Berg Balance Scale (BBS), Timed Up and Go (TUG), and Tinetti in random order. Future falls were recorded for 12 months following testing. The FSST accurately distinguished between non-fallers and multiple fallers, and the 15-second threshold score accurately distinguished multiple fallers from non-multiple fallers based on fall history. The FSST predicted future falls, and performance on the FSST was significantly correlated with performance on the BBS, TUG, and Tinetti. However, the test is not appropriate for older adults who use walkers. Overall, the FSST is a valid yet underutilized measure of balance performance and fall prediction tool that physical therapists should consider using in ambulatory community dwelling older adults.     

Effects of concurrent cognitive task on pre-landing muscle response latency during stepping down activity in older adults with and without a history of falls

Purpose. To investigate the co-contraction of ankle muscles in older subjects with and without a history of falls during a stepping down activity, and whether the co-contraction was disrupted by a concurrent cognitive task.

Method. Ten fallers and 9 non-fallers (mean age = 72.0 ± 5.0 and 72.1 ± 7.3 years, respectively) were recruited. Electromyography (EMG) of the tibialis anterior (TA) and medial gastrocnemius (MG) was recorded during stepping down with and without a concurrent cognitive task. Co-contraction was investigated using the time between the EMG onset and the foot touching a force-platform, termed the pre-landing muscle response latency.

Results. The fallers showed longer pre-landing muscle response latencies in the TA compared with non-fallers (141.1 ± 58.1 ms and 110.9 ± 68.2 ms, respectively). With a concurrent cognitive task, the pre-landing muscle response latencies in the TA were shortened in fallers significantly more than in non-fallers (44.4% and 15.5%, respectively). No significant difference in MG activation was found between 2 groups in the stepping down activity with and without cognitive task.

Conclusions. Subjects with history of falls exhibit a greater shortening in the pre-landing muscle response latency than non-fallers when distracted during stepping down. Disruption of their co-contraction in ankle joint might precipitate such older adults to fall.     

Ballistic Resistance Training: Feasibility,Safety, and Effectiveness for Improving Mobility in Adults With Neurologic Conditions: A Systematic Review

ObjectivesTo determine whether ballistic resistance training is feasible, safe, and effective in improving muscle strength, power generation, and mobility in adults with neurologic conditions.Data SourcesNine electronic databases were searched from inception to March 2019 in addition to the reference lists of included articles.Study SelectionArticles were independently screened by 2 authors and were included if they were full-text; English-language articles published in a peer-reviewed journal; investigated ballistic resistance training for adults with a neurologic condition; and reported on feasibility, safety, strength, power, or mobility.Data ExtractionTwo authors independently extracted data. Study quality was assessed using the McMaster critical review form and the Physiotherapy Evidence Database scale.Data SynthesisThe search identified 1540 articles, with 13 articles describing 9 studies meeting the criteria for inclusion. Five studies were randomized controlled trials and 4 were cohort studies. Ballistic resistance training was feasible and safe with only 1 intervention-related adverse event reported. Findings indicated improvements in strength for hip abduction, leg press, knee flexion, and ankle dorsiflexion, but not for hip flexion, hip extension, knee extension, or ankle plantarflexion. Muscle power generation improved for hip flexion, hip abduction, leg press, knee extension, and knee flexion, but not for ankle plantarflexion. Treatment effect was positive for self-selected walking speed, with a standardized mean difference (SMD) of 0.69 (95% confidence interval [CI], 0.01-1.38) from 3 studies. However, fastest comfortable walking speed results were inconclusive with a SMD from 4 studies of 0.45 (95% CI, –0.01 to 0.91).ConclusionsBallistic training is safe and feasible for people with a neurologic condition. The effects on muscle strength, power generation, and mobility were found to be positive but not conclusive.     

Effects of Sun-style Tai Chi exercise on physical fitness and fall prevention in fall-prone older adults

AIM: This paper reports a study to determine changes in the physical fitness (knee and ankle muscle strength, balance, flexibility, and mobility), fall avoidance efficacy, and fall episodes of institutionalized older adults after participating in a 12-week Sun-style Tai Chi exercise programme. BACKGROUND: Fall prevention has a high priority in health promotion for older people because a fall is associated with serious morbidity in this population. Regular exercise is effective in fall prevention for older adults because of improvements in strength and balance. Tai Chi exercise is considered to offer great potential for health promotion and rehabilitation, particularly in the maintenance of good mental and physical condition in older people. METHODS: A quasi-experimental design with a non-equivalent control group was used. Data were collected from September 2001 to January 2002. A total of 68 fall-prone older adults with a mean age of 77.8 years participated in the study, and 29 people in the Tai Chi group and 30 controls completed the post-test measures. The Tai Chi exercise programme was provided three times a week for 12 weeks in the experimental group. Data were analysed for group differences using t-tests. RESULTS: At post-test, the experimental group showed significantly improved muscle strength in knee and ankle flexors (P < 0.001) and extensors (P < 0.01), and improved flexibility (P < 0.01) and mobility (P < 0.001) compared with the control group. There was no significant group difference in fall episodes, but the relative risk ratio for the Tai Chi exercise group compared with the control group was 0.62. The experimental group reported significantly more confidence in fall avoidance than did the control group. CONCLUSION: The findings reveal that Tai Chi exercise programmes can safely improve physical strength and reduce fall risk for fall-prone older adults in residential care facilities.     

Isometric performance following total hip arthroplasty and rehabilitation

We compared differences in isometric strength between older adults who have undergone elective unilateral total hip arthroplasty (THA) and completed rehabilitation with a population of community-dwelling older adults who have not had THA. The study was a cross-sectional design, and 22 unilateral THA subjects and 38 community-dwelling older adults participated. THA subjects received on average 13 outpatient or home-based physical therapy sessions before evaluation. THA subjects were evaluated 4 to 5 months postsurgery. We assessed isometric muscle strength by measuring peak hip torque per body weight with a robotic dynamometer during abduction, flexion, and extension. No significant performance differences were observed between operated and nonoperated hips of THA subjects. THA subject operated and nonoperated hips generated significantly less peak torque per body weight during flexion (p = 0.03) compared with community-dwelling older adult hips (THA subject operated hips = 6.96 ft-lb/lb, THA subject nonoperated hips = 8.26 ft-lb/lb, community-dwelling older adult hips = 11.56 ft-lb/lb). No significant differences were observed between THA subjects and community-dwelling older adults during hip extension (p = 0.55) or abduction (p = 0.17). At 4 to 5 months postsurgery, THA subjects were not at the same level of biomechanical performance as community-dwelling older adults. Significant strength deficits were found in THA subject operated versus nonoperated hips during isometric flexion. Additional or modified physical therapy that targets the hip flexors is recommended after THA.     

Effects of step length,age, and fall history on hip and knee kinetics and knee co-contraction during the maximum step length test

Background

Maximum step length is a brief clinical test involving stepping out and back as far as possible with the arms folded across the chest. This test has been shown to predict fall risk, but the biomechanics of this test are not fully understood. Knee and hip kinetics (moments and powers) are greater for longer steps and for younger subjects, but younger subjects also step farther.

Methods

To separate the effects of step length, age, and fall history on joint kinetics; healthy younger (age=27(5), N=14), older non-fallers (age=72(5), N=14), and older fallers (age=75(6), N=11) all stepped to the same relative target distances of 20–80% of their height. Knee and hip kinetics and knee co-contraction were calculated.

Findings

Hip and knee kinetics and knee co-contraction all increased with step length, but older non-fallers and fallers utilized greater stepping hip and less stepping knee extensor kinetics. Fallers had greater stepping knee co-contraction than non-fallers. Stance knee co-contraction of non-fallers was similar to young for shorter steps and similar to fallers for longer steps.

Interpretation

Age had minimal effects and fall history had no effects on joint kinetics of steps to similar distances. Effects of age and fall history on knee co-contraction may contribute to age-related kinetic differences and shorter maximal step lengths of older non-fallers and fallers, but step length correlated with every variable tested. Thus, declines in maximum step length could indicate declines in hip and knee extensor kinetics and impaired performance on similar tasks like recovering from a trip.     

Musculoskeletal profile of male collegiate soccer players

Twenty-five collegiate soccer players were evaluated for lower extremity flexibility and muscle strength at the end of preseason training and before the onset of the collegiate soccer season on two successive seasons. The purpose of the evaluation was to determine whether symmetry was present in their legs and whether deficits in flexibility or strength would affect the susceptibility to hamstring or groin muscle strain injuries. The mean (+/- SE) flexibility of the dominant leg for hip abduction was 41 degrees +/- 1.2 degree; for hip flexion, 76 degrees +/- 1.9 degree; for hip extension, 174 degrees +/- 0.7 degree; and for ankle dorsiflexion, 33 degrees +/- 1.3 degree. The mean (+/- SE) isokinetic torque of the dominant leg (tested at 30 degrees per second) for knee extension was 214 +/- 8 newton meters and for flexion was 128 +/- 4 newton meters, while isometric strength for hip flexion was 315 +/- 8 newtons and for ankle plantar flexion was 1721 +/- 58 newtons. No significant differences were found between the dominant and nondominant legs in flexibility or strength. During this study no hamstring or groin strain injuries occurred. The lack of leg muscle strain injuries appeared to be directly related to the initiation of a controlled warmup and stretching program and underlines the importance of this in injury prevention. Interestingly, more than 50% (13 of 25) of the players were found to have significant deficits in one or more specific muscle groups. Two athletes sustained low back strain injuries and one athlete had a knee sprain injury.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of ankle proprioceptive interference on locomotion after stroke

Lin S-I, Hsu L-J, Wang H-C. Effects of ankle proprioceptive interference on locomotion after stroke.ObjectiveTo examine the effects of vibration-induced ankle proprioceptive interference on the locomotion of patients with stroke with intact and impaired ankle joint position sense (JPS).DesignCross-sectional.SettingRehabilitation department in a tertiary hospital.ParticipantsAmbulatory patients (N=35) with unilateral stroke received an ankle joint repositioning test and were classified into intact (n=16) or impaired (n=19) JPS group.InterventionsNone.Main Outcome MeasuresThe plantar sensitivity and leg muscle strength were tested. Patients were instructed to walk at a self-selected pace on a computerized pressure sensor walkway under 3 conditions: no, affected, or unaffected Achilles' tendon vibration. The stride characteristics of the affected limb were analyzed.ResultsPatients with intact and impaired JPS did not differ in their plantar sensitivity or leg muscle strength. The differences in the stride characteristics were nonsignificant between vibration and nonvibration conditions. Shorter single support and longer swing phase were found with the affected side vibration compared with the unaffected side vibration. Patients with intact and impaired JPS did not respond to the proprioceptive interference differently.ConclusionsAfter stroke, there could be changes in the central sensory regulation for locomotion control and vibration-induced afferent inputs from the ankle might be viewed as sensory disturbances. Further studies that manipulate other sensory inputs are needed to gain a better understanding of the central sensory integration for locomotion control after stroke.     

A pilot study of falls risk and vestibular dysfunction in older fallers presenting to hospital emergency departments

PURPOSE: To compare falls risk in older fallers and non-fallers, with an emphasis on dizziness and signs of vestibular dysfunction. METHOD: The fallers had presented to the Emergency Department of the Royal Melbourne Hospital, Australia following a fall and were discharged directly home (n = 20) (75% female, mean age 78 years). The non-fallers were an age and gender matched group, who had not fallen in the past 12 months (n = 20). All clients received a home-based assessment, which involved a comprehensive assessment of falls risk. RESULTS: Over three-quarters of the fallers took four or more medications, had balance impairments, and used a gait aid in the community. The fallers had a significantly higher falls risk score (P < 0.001), demonstrated significantly poorer balance (P < 0.001) and walked significantly more slowly (P < 0.001) than the non-fallers. There was no significant difference between the groups in their reports of dizziness (P = 0.68), although static balance testing (CTSIB condition 5) suggested a greater degree of underlying vestibular dysfunction in the group of fallers (P < 0.001). CONCLUSION: Older people discharged home from the ED following a fall are at high risk of falling in the future and have a greater level of vestibular dysfunction based on simple clinical testing. Additional clinically applicable tests of vestibular function are required to further investigate the relationship between vestibular dysfunction and falling in older people.     

Which Neuromuscular Attributes Are Associated With Changes in Mobility Among Community-Dwelling Older Adults With Symptomatic Lumbar Spinal Stenosis?

Objectives

To identify neuromuscular attributes associated with mobility and changes in mobility over 2 years of follow-up among patients with and without symptomatic lumbar spinal stenosis (SLSS).

Surgery simulation analysis of anterior advancement of the tibial tuberosity

The objective of this study is to evaluate the surgical outcome of anterior displacement of the tibial tuberosity (Maquet procedure) for reducing patellofemoral joint contact force. Thein-vivo experimental knee joint geometric data with a biomechanical model was used to do the simulation of the Maquet procedure. Six healthy young adults performed weight-bearing knee flexion-extension by ascending a one-step stair. Dynamic X-ray images of the knee were continuously recorded by a video-fluoroscopic system. These X-ray images were analysed on a computerized digitizing system to get the knee joint geometric data. Based on the continuous in-vivo geometric data, computer surgery simulation was studied on six right knees with advancement of 3, 5, 10, 15, and 20 degrees of the patellar tendon insertion. Evaluation of the simulation consequences from a biomechanical view point showed that the Maquet procedure reduced the patellofemoral joint reaction force only up to 20% at 90 degrees of knee flexion angle. The patellofemoral joint reaction force had 50% reduction only when the knee flexion angle less than 20 degrees, and only when the patellar tendon was moved out by 15 or 20 degrees. This represented nearly 1 in. of the anterior displacement of the tibial tuberosity. The results also showed that the Maquet procedure would decrease up to 20% of the force transmission efficiency of the patellofemoral mechanism, which would cause the mechanical consequences of the operation to be only minor at larger knee flexion angles more than 20 degrees. These findings suggest that the Maquet procedure is only favourable to less active or older patients having small knee flexion angle activities. RELEVANCE: Surgical procedure of anterior displacement of the tibial tuberosity has been used to reduce the patellofemoral joint contact force for treatment of symptomatic osteoarthrosis of the patellofemoral joint. In this study the patellofemoral joint reaction force had 50% reduction only when the knee flexion angle was less than 20 degrees, and only when patellar tendon was moved out nearly 1 in. Based on this result, the Maquet procedure is suggested only favourable to less active or older patients having small knee flexion angle activities.     

Falls in the elderly: Part II, Balance, strength, and flexibility

The purpose of this study was to determine and compare the balance, muscular strength, and flexibility of two groups of elderly adults: one with a history of falls (HF) and one with no history of falls (NHF). Subjects were 19 men and 36 women. Static and dynamic balance was determined by a one-foot stance balance test and a backwards walking test. Hip, knee, and ankle joint muscular strength were assessed on a Cybex Leg Press Dynamometer. A goniometer was used to determine hip, knee, and ankle joint range of motion (flexibility), ANOVA indicated a significant difference between the two groups for static balance (p less than .001), leg strength (p less than .01), and hip and ankle flexibility (p less than .01). The results suggest that balance, leg strength, and flexibility may be factors contributing to falls in the elderly.     

Impaired control of weight bearing ankle inversion in subjects with chronic ankle instability

Background

Previous studies have proposed that evertor muscle weakness represents an important factor affecting chronic ankle instability. For research purposes, ankle evertor strength is assessed by means of isokinetic evaluations. However, this methodology is constraining for daily clinical use. The present study proposes to assess ankle evertor muscle weakness using a new procedure, one that is easily accessible for rehabilitation specialists. To do so, we compared weight bearing ankle inversion control between patients suffering from chronic ankle instability and healthy subjects.

Methods

12 healthy subjects and 11 patients suffering from chronic ankle instability conducted repetitions of one leg weight bearing ankle inversion on a specific ankle destabilization device equipped with a gyroscope. Ankle inversion control was performed by means of an eccentric recruitment of evertor muscles. Instructions were to perform, as slow as possible, the ankle inversion while resisting against full body weight applied on the tested ankle.

Results

Data clearly showed higher angular inversion velocity peaks in patients suffering from chronic ankle instability. This illustrates an impaired control of weight bearing ankle inversion and, by extension, an eccentric weakness of evertor muscles.

Interpretation

The present study supports the hypothesis of a link between the decrease of ankle joint stability and evertor muscle weakness. Moreover, it appears that the new parameter is of use in a clinical setting.     

Foot and ankle strength, range of motion, posture, and deformity are associated with balance and functional ability in older adults

Spink MJ, Fotoohabadi MR, Wee E, Hill KD, Lord SR, Menz HB. Foot and ankle strength, range of motion, posture, and deformity are associated with balance and functional ability in older adults.

Objective

To determine the extent to which measures of foot and ankle strength, range of motion, posture, and deformity are associated with performance in a battery of balance and functional ability tests in older adults.

Design

Cross-sectional study of people over 65 years.

Setting

Community.

Participants

Participants (N=305; age range, 65–93y) recruited for a randomized trial investigating the efficacy of a podiatry intervention to prevent falls.

Interventions

Not applicable.

Main Outcome Measures

Clinical measures of foot and ankle strength (using hand-held dynamometry), range of motion, posture, and deformity, and a battery of balance tests (postural sway, maximum balance range, lateral stability, coordinated stability) and functional ability tests (alternate step test, sit-to-stand, timed 6-m walk).

Results

Most (67/88) of the correlations between the foot and ankle tests and performance on the balance and functional tests were statistically significant. Hierarchic linear regression analysis identified hallux plantar flexion strength and ankle inversion-eversion range of motion to be the most consistent significant and independent predictors of balance and functional test performance, explaining up to 25% of the variance in the test scores.

Conclusions

Foot and ankle characteristics, particularly plantar flexor strength of the hallux and ankle inversion-eversion range of motion, are important determinants of balance and functional ability in older people. Further research is required to establish whether intervention programs that include strengthening and stretching exercises for the foot and ankle may achieve improvements in balance and functional ability and reduce the risk of falls in older people.     

The influence of age and fall history on single transition step kinematics

BackgroundThe risk of falls during locomotion increases with age, and step negotiation is one of the most hazardous types of gait for older adults. Further, a history of a fall is one of the strongest predictors of a future fall; and women fall more frequently, and incur greater medical costs, compared to men. The purpose of the study was to identify lower extremity kinematic factors associated with transition step clearance and foot placement in young women and older women with and without a fall history.MethodsForty-five female participants (15 per group) completed trials that consisted of walking barefoot along a raised walkway at a self-selected speed, descending a 17 cm step, and continued level ground walking. Variables of interest included lead and trail limb minimum step clearance and foot placement, and bilateral lower extremity joint positions at step clearance and at lead foot initial contact.FindingsSignificant group differences, with large effect sizes, were found in lead foot placement and knee flexion position at initial contact. Both older groups landed more closely to the step and made initial contact with the lead knee in a more flexed position compared to the young group.InterpretationThe kinematic differences may be a strategy utilized by older adults to create an early landing to minimize time in single limb stance and compensate for age-related loss of lower extremity strength, range of motion, and/or balance. However, the greater knee flexion may also increase the risk a fall due to lead limb collapse.     

Age and falls history effects on antagonist leg muscle coactivation during walking with balance perturbations

BackgroundInspired by a reliance on visual feedback for movement control in older age, optical flow perturbations provide a unique opportunity to study the neuromuscular mechanisms involved in walking balance control, including aging and falls history effects on the response to environmental balance challenges. Specifically, antagonist leg muscle coactivation, which increases with age during walking, is considered a neuromuscular defense against age-associated deficits in balance control. The purpose of this study was to investigate the effects of age and falls history on antagonist leg muscle coactivation during walking with and without optical flow perturbations of different amplitudes.MethodsEleven young adults [mean (standard deviation) age: 24.8 (4.8) years], eleven older non-fallers [75.3 (5.4) years] and eleven older fallers [age: 78 (7.6) years] participated in this study. Participants completed 2-minute walking trials while watching a speed-matched virtual hallway that, in some conditions, included mediolateral optical flow perturbations designed to elicit the visual perception of imbalance.FindingsWe first found that lower leg antagonist muscle coactivation during normal walking increased with age, independent of falls history. We also found that older but not young adults increased antagonist leg muscle coactivation in the presence of optical flow perturbations, with more pervasive effects in older adults with a history of falls.InterpretationOur findings allude to a greater susceptibility to optical flow perturbations in older fallers during walking, which points to a higher potential for risk of instability in more complex and dynamic everyday environments. These findings may also have broader impacts related to the design of innovative training paradigms and neuromuscular targets for falls prevention.     

Use of an Instrumented Timed Up and Go (iTUG) for Fall Risk Classification

Abstract

Aim: To determine if an instrumented Timed Up and Go (iTUG) can accurately classify older adult recurrent fallers and non-fallers who are age and sex-matched. Methods: iTUG data from older adult recurrent fallers (n?=?25) and age and sex-matched non-fallers (n?=?25) were selected for comparison from a pool of participants (n?=?148) that were involved in a larger age and mobility related study. Results: All of the iTUG measures demonstrated a low level of accuracy in classifying recurrent fallers from non-fallers (AUC?=?0.49–0.56) and there were no significant differences in any of the iTUG performance measures between groups. Conclusion: The iTUG was unable to appropriately classify or differentiate older adult recurrent fallers from non-fallers who were both age and sex-matched. The role and usefulness of body-worn sensors for assessing mobility and fall risk require further investigation.     

Gait symmetry and walking speed analysis following lower-extremity trauma

BACKGROUND AND PURPOSE: Gait has been shown to be a major determining factor of function following limb-salvage surgery. However, little is known regarding the measures associated with gait recovery for this patient population. The purpose of this study was to identify clinical measures associated with impaired walking speed and gait asymmetry in patients with lower-extremity reconstruction. SUBJECTS: Study subjects were 381 patients from the Lower Extremity Assessment Project (LEAP) who had undergone reconstruction following severe lower-extremity trauma. METHODS: The LEAP study was a longitudinal study of outcomes following lower-extremity reconstruction. The present study used 24-month clinical follow-up data. A combined outcome measure of reduced walking speed and gait deviation was chosen to provide a comprehensive measure of impaired physical mobility. RESULTS: The most significant clinical factors associated with decreased walking speed and gait deviation were impaired ankle plantar-flexion range of motion, knee flexion strength, and a nonreciprocal stair-climbing pattern. DISCUSSION AND CONCLUSION: The findings provide clinicians with specific clinical measures associated with functional recovery in patients with lower-limb reconstruction. These measures, in turn, can be considered to inform treatment decision making and to prioritize interventions.