Elsie G. Culham

Physical Function and Health Status among Seniors with and without a Fear of Falling

Background: Fear of falling (FF) is pervasive among older people and is an independent risk factor for decreased mobility and loss of quality of life. Although it is a serious health concern, little is known about the severity of the physical and health-related deficits in high-functioning fearful seniors. Objective: This study examined the physical correlates of FF in community-dwelling seniors in relation to their non-fearful counterparts and also explored the relevance of recent fall history. Subjects: Twenty-five volunteers who stated that they had curtailed their activities due to a FF and who reported themselves to be healthy participated. Non-fearful, age- and gender-matched subjects were also recruited and served as a comparison group. Methods: This cross-sectional study had participants come to the laboratory on one occasion for about 1.5 h. Limits of balance stability, walking speed, and lower limb muscle strength were measured in random order. In addition, the SF-36, the Activities-specific Balance Confidence (ABC) scale and the Human Activity Profile questionnaires were completed to provide measures of heath status, FF and activity levels, respectively. Results: Subjects with a FF had lower ABC scores (69.8 ± 10.2) than controls (90.2 ± 7.9; p < 0.001), and although they reported activity curtailment, the groups presented similar activity profiles (p > 0.05). Balance ability was not compromised in seniors with a FF, although their walking speed was slower than that of control subjects (p < 0.004). Lower limb weakness was significant in the FF group, which also reported low physical health. Perceived physical health, activity and hip flexor torque in combination accounted for almost 62% of the variance in ABC scores. Secondary analysis of the data from the FF group revealed a tendency for those who had fallen in the past year to restrict their limits of stability compared to those who had not fallen; though generally the effect sizes were small to moderate. Conclusions: The marked deficits in strength and health status found among seniors living independently in the community, who are in good health, but report being fearful of falling underscores the seriousness of FF as a potential health risk factor in the well elderly.

Reducing fear of falling in seniors through education and activity programs: a randomized trial.

OBJECTIVES: To determine the relative effect of education and activity programs on fear of falling, balance, strength, and health status.

Falls and injury prevention should be part of every stroke rehabilitation plan

Objective: To evaluate falls incidence, circumstances and consequences in people who return home after stroke rehabilitation, so that appropriate falls and injury prevention strategies can be developed. Design: Prospective cohort study. Setting: Community. Subjects: Fifty-six subjects with stroke who were participating in a rehabilitation programme and returning to live in a community setting completed the study. Main measures: Subjects completed a prospective falls diary for six months after discharge from rehabilitation, and were interviewed after falls. Physical function was measured by the Berg Balance Scale (BBS) and the Functional Independence Measure (FIM). Results: Forty-six per cent of people (26/56) fell, with most falls (63/103 falls) occurring in the two months after discharge from rehabilitation. One subject had 37 similar falls and these falls were excluded from further analysis. Falls occurred more often indoors (50/66), during the day (46/66) and towards the paretic side (25/66). People required assistance to get up after 25 falls (38%) and 36 falls (55%) resulted in an injury. People sought professional health care after only 16 falls, and activity was restricted after 29 falls (44%). The Berg Balance Scale and Functional Independence Measure scores were lower in people who had longer lies after a fall, and who restricted their activity after a fall (p < 0.05). Lower physical function scores were also associated with falling in the morning, wearing multifocal glasses at the time of a fall, and injurious falls (p < 0.05). Conclusion: Falls are common when people return home after stroke. Of concern are the small number seeking health professionals’ assistance after a fall, the high proportion restricting their activity as a result of a fall and the number of falls occurring towards the paretic side.

Effect of a Home Program of Hip Abductor Exercises on Knee Joint Loading, Strength, Function, and Pain in People With Knee Osteoarthritis: A Clinical Trial

Background Hip abductor muscle weakness may result in impaired frontal-plane pelvic control during gait, leading to greater medial compartment loading in people with knee osteoarthritis (OA). Objective This study investigated the effect of an 8-week home strengthening program for the hip abductor muscles on knee joint loading (measured by the external knee adduction moment during gait), strength (force-generating capacity), and function and pain in individuals with medial knee OA. Design The study design was a nonequivalent, pretest-posttest, control group design. Setting Testing was conducted in a motor performance laboratory. Patients An a priori sample size calculation was performed. Forty participants with knee OA were matched for age and sex with a control group of participants without knee OA. Intervention Participants with knee OA completed a home hip abductor strengthening program. Measurements Three-dimensional gait analysis was performed to obtain peak knee adduction moments in the first 50% of the stance phase. Isokinetic concentric strength of the hip abductor muscles was measured using an isokinetic dynamometer. The Five-Times-Sit-to-Stand Test was used to evaluate functional performance. Knee pain was assessed with the Western Ontario and McMaster Universities Osteoarthritis Index questionnaire. Results Following the intervention, the OA group demonstrated significant improvement in hip abductor strength, but not in the knee adduction moment. Functional performance on the sit-to-stand test improved in the OA group compared with the control group. The OA group reported decreased knee pain after the intervention. Limitations Gait strategies that may have affected the knee adduction moment, including lateral trunk lean, were not evaluated in this study. Conclusions Hip abductor strengthening did not reduce knee joint loading but did improve function and reduce pain in a group with medial knee OA.

Static and dynamic biomechanics of foot orthoses in people with medial compartment knee osteoarthritis.

OBJECTIVE Gait biomechanics (knee adduction moment, center of pressure) and static alignment were investigated to determine the mechanical effect of foot orthoses in people with medial compartment knee osteoarthritis. DESIGN Repeated measures design in which subjects were exposed to three conditions (normal footwear, heel wedge and orthosis) in random order. BACKGROUND The knee adduction moment is an indirect measure of medial compartment loading. It was hypothesized that the use of a 5 degrees valgus wedge and 5 degrees valgus modified orthosis would shift the center of pressure laterally during walking, thereby decreasing the adduction moment arm and the adduction moment. METHODS Peak knee adduction moment and center of pressure excursion were obtained in nine subjects with medial compartment knee OA during level walking using an optoelectric system and force plate. Static radiographs were taken in 12 subjects using precision radiographs. RESULTS There was no difference between conditions in static alignment, the peak adduction moment or excursion of the center of pressure in the medial-lateral direction. No relationship was found between the adduction moment and center of pressure excursion in the medial-lateral plane. The displacement of the center of pressure in the anterior-posterior direction, measured relative to the laboratory coordinate system, was decreased with the orthosis compared to the control condition (P=0.036) and this measure was correlated with the adduction moment (r=0.45, P=0.019). CONCLUSIONS The proposed mechanism was not supported by the findings. The reduction in the center of pressure excursion in the anterior-posterior direction suggests that foot positioning was altered, possibly to a toe-out position, while subjects wore the orthoses. Based on the current findings, we hypothesize that toe-out positioning may reduce medial joint load. RELEVANCE Knee Osteoarthritis is the most common cause of chronic disability amongst seniors. Developing inexpensive, non-invasive treatment strategies for this large population has potential to impact health care costs, quality of life and clinical outcomes.

Radiographic and non-invasive determination of the hip joint center location: effect on hip joint moments.

OBJECTIVE To determine which of four non-invasive measures is most accurate in locating the hip joint center. BACKGROUND The location of the joint centers must be accurately determined in three dimensions for calculation of the moments of force during gait. It is not known which of the several non-invasive methods available for location of the hip center is most accurate. DESIGN Hip center location was determined using standardized X-rays and four non-invasive methods which utilized measured distances between bony landmarks in 10 healthy subjects. Hip moments during gait were obtained from optical tracking, force plate and anthropometric data. RESULTS The most accurate non-invasive method of locating the hip center was by taking the midpoint of a line connecting the antero-superior iliac spine and the symphysis pubis and moving inferiorly 2 cm. Using this approach the hip center was located 0.7 cm medial and 0.8 cm superior to its true location determined using the standardized X-rays. The 95% confidence interval of the maximum error difference in moments measured between this method and the standardized X-rays ranged from -0.15 to 0.4 Nm/kg in the frontal plane, -0.03 to 0.07 Nm/kg in the sagittal plane and -0.05 to -0.03 Nm/kg in the transverse plane. CONCLUSIONS Locating the hip center based on the distance between the antero-superior iliac spine and the symphysis pubis is a valid technique for estimating the hip center in routine gait analysis.

Balance, Muscle Strength, and Fear of Falling in Older Adults

This study examined balance ability, lower-extremity muscle strength, fear of falling and their inter-relationships in 40 community-dwelling older adults (>65 years). Subjects who self-identified either as being fearful offalling or not (no concern) were screened to exclude those with known risk factors for falling. Limits of stability, maximal isometric strength, gait speed, and fear of falling were contrasted between groups (27 control subjects, 13 fearful subjects). Those fearful of falling demonstrated smaller center of pressure (COP) excursions in anterior, left, and right directions ( p <.0001) and used a smaller percentage of their base of support during maximal weight shifting in combined anterior-posterior and right-left directions ( p <.001) compared to the control group. Strength did not differ between groups, but was associated with the ability to shift the COP in the anterior-posterior direction ( p <.05). Fear of falling also related to weight shifting ability ( p <.017). Seniors fearful of falling demonstrated limitations in balance ability and balance confidence that could not be explained by muscle weakness.

Radiographic measures in subjects who are asymptomatic and subjects with patellofemoral pain syndrome.

Lateral tilt and displacement of the patella are considered characteristic features of patellofemoral pain syndrome. It has been suggested that abnormal patellar tilt and displacement are detected best with the knee near full extension, which requires computed tomography or magnetic resonance imaging. The objective of the current study was to determine whether alignment abnormalities could be detected in subjects with patellofemoral pain syndrome from axial radiographs obtained at 35° knee flexion using a new, standardized radiographic technique. Thirty-three subjects with patellofemoral pain syndrome and 33 matched control subjects were recruited from a military population. Lateral and axial (unloaded and with quadriceps contraction) radiographs were taken using the Patellofemoral QUESTOR™ Precision Radiograph system. Measures of patellar tilt and displacement, and anatomic measures (sulcus angle, patellar facet angle, patella alta) were obtained from the radiographs. No significant differences in patellar tilt or displacement were detected between the groups (paired t tests) in either the unloaded or loaded (quadriceps contracted) condition, suggesting that these measures, obtained at this knee angle are not useful diagnostic or outcome measures in patellofemoral pain syndrome. Patellar angle, sulcus angle, and patellar height also did not differ between groups suggesting that these are not etiologic factors in patellofemoral pain syndrome.

Sensory-Specific Balance Training in Older Adults: Effect on Position, Movement, and Velocity Sense at the Ankle

Background and Purpose Age-related changes in proprioception contribute to impairments in postural control and increased fall risk in older adults. The purpose of this randomized controlled trial was to examine the effects of balance exercises on proprioception. Subjects The participants were 36 older people and 24 younger people who were healthy. Methods Older participants were randomly assigned to a balance exercise group (n=17) or a falls prevention education group (n=19). Baseline, postintervention, and 8-week follow-up measurements of 3 proprioceptive measures (threshold to perception of passive movement, passive joint position sense, and velocity discrimination) were obtained at the ankle. For comparative purposes, younger participants underwent a one-time assessment of the 3 proprioceptive measures. Results Postintervention improvements in velocity discrimination were found in the balance exercise group when compared with values at baseline and in the falls prevention education group. Age-related differences found at baseline were reduced in the balance exercise group after intervention. Improvements were not maintained at the 8-week follow-up. Threshold to perception of passive movement and passive joint position sense did not change as a function of the exercise intervention. Discussion and Conclusion The results suggest that short-term improvements in velocity sense, but not movement and position sense, may be achieved following a balance exercise intervention.

Sensory-Specific Balance Training in Older Adults: Effect on Proprioceptive Reintegration and Cognitive Demands

Background and Purpose: Age-related changes in the ability to adjust to alterations in sensory information contribute to impaired postural stability. The purpose of this randomized controlled trial was to investigate the effect of sensory-specific balance training on proprioceptive reintegration. Subjects: The subjects of this study were 36 older participants who were healthy. Methods: Participants were randomly assigned to a balance exercise group (n=17) or a falls prevention education group (n=19). The primary outcome measure was the center-of-pressure (COP) velocity change score. This score represented the difference between COP velocity over 45 seconds of quiet standing and each of six 5-second intervals following proprioceptive perturbation through vibration with or without a secondary cognitive task. Clinical outcome measures included the Fullerton Advanced Balance (FAB) Scale and the Activities-specific Balance Confidence (ABC) Scale. Assessments were conducted at baseline, postintervention, and at an 8-week follow-up. Results: Following the exercise intervention, there was less destabilization within the first 5 seconds following vibration with or without a secondary task than there was at baseline or in the falls prevention education group. These training effects were not maintained at the 8-week follow-up. Postintervention improvements also were seen on the FAB Scale and were maintained at follow-up. No changes in ABC Scale scores were identified in the balance exercise group, but ABC Scale scores indicated reduced balance confidence in the falls prevention education group postintervention. Discussion and Conclusion: The results of this study support short-term enhanced postural responses to proprioceptive reintegration following a sensory-specific balance exercise program.