Characteristic gait patterns in older adults with obesity--results from the Baltimore Longitudinal Study of Aging

Influence of body mass index on sagittal hip range of motion and gait speed recovery six months after total hip arthroplasty

PURPOSE

In practice, obesity leads to poor functional outcomes after total hip arthroplasty (THA). However, in clinical research, the influence of body mass index (BMI) on the gait recovery and kinematics for THA is not well documented. The purpose of this study was to assess the influence of BMI on gait parameters pre-operatively and six months after THA for hip osteoarthritis (OA) patients.

METHODS

We included 76 THA for hip OA: non-obese group (G1): 49 (BMI < 30 kg/²) and obese group (G2): 37 (BMI ≥ 30 kg/m²) with a control group of 61 healthy people. Clinical evaluation (HOOS) and a 3D gait analysis (gait speed and flexion range of the hip (ROM)) were performed before and six months after THA: The gains between the two visits were calculated and we looked for correlations between outcomes and BMI.

RESULTS

Preoperative gait speed and hip ROM were significantly lower in obese patients (speed G1: 0.81 ± 0.22 m/s vs. G2: 0.64 ± 0.23 m/s, p = 0.004 and hip ROM G1: 26.1° ± 7.3 vs. G2: 21.4° ± 6.6, p = 0.005), and obese patients were more symptomatic. At six months, gait speed and hip ROM were significantly lower for all patients compared with the control group. No correlation between gait velocity, hip ROM, and BMI was found. Biomechanical and clinical gains were comparable in the two groups.

CONCLUSIONS

All patients, including obese patients, have significant functional improvement after THA, objectively assessed by gait speed. Even if patients did not fully recover to the level of a healthy control person after THA, functional gain is comparable irrespective of BMI.

The effect of body mass index, lower extremity performance, and use of a private car on incident life-space restriction: a two-year follow-up study

Background

The purpose of the study was to explore the single and combined contributions of body mass index (BMI) and lower extremity performance as modifiable physical factors, and the influence of use of a private car as an environmental factor on prevalent and incident life-space restriction in community-dwelling older people.

Methods

Community-dwelling people aged 75–90 years (n = 823) participated in the Life-Space Mobility in Old Age (LISPE) two-year follow-up study. Participants who reported that the largest life-space area they had attained, without aid from any device or another person, was the neighborhood or less were considered to have life-space restriction. Incident life-space restriction was the endpoint of Cox’s proportional hazard model. BMI, lower extremity performance (Short Physical Performance Battery, SPPB), and use of a private car were predictors.

Results

At baseline, people who had both obesity (BMI ≥30.0) and impaired lower extremity performance (SPPB 0–9) had a higher prevalence of life-space restriction (prevalence ratio 3.6, 95% confidence interval, CI, 2.0–6.3) compared to those with normal weight (BMI 23.0–24.9) and intact physical performance (SPPB 10–12). The 581 people without life-space restriction at the baseline contributed 1033 person-years during the two-year follow-up. Incident life-space restrictions were reported by 28.3% participants. A higher hazard ratio (HR) for incident life-space restriction was observed in subjects having both obesity and impaired lower extremity performance (HR 3.6, 95% CI, 1.7–7.4), impaired lower extremity performance only (HR 1.9, 95% CI 0.9–4.1), and obesity only (HR 1.8, 95% CI, 0.9–3.5) compared to those with normal weight and intact performance. Private car passengers (HR 2.0, 95% CI, 1.3–3.0) compared to car drivers had a higher risk of life-space restriction. All models were adjusted for age, sex, chronic diseases, and education.

Conclusions

Older people with impaired lower extremity performance have an increased risk of incident life-space restriction especially if combined with obesity. Also, not driving a car renders older people vulnerable to life-space restriction.

Implication of obesity on motion, posture and internal stress of the foot: an experimental and finite element analysis

Obesity causes increased loading on the foot which can damage the soft tissue and bone ultimately leading to foot problems. Experimental and computational methods were used to analyse the chain of biomechanical changes in the lower limb due to obesity. The experimental study shows some changes in foot posture and gait where obese subjects were more likely to have pronated feet, smaller joint angles in the sagittal and frontal planes, smaller cadence, and smaller stride length. Anatomically correct finite element models generated on obese subjects showed increased and altered internal and plantar stress.  Altered foot posture was identified as a key indicator of increased internal stress indicating the importance of foot posture correction.

Use of various obesity measurement and classification methods in occupational safety and health research: a systematic review of the literature

BACKGROUND

This study systematically examined obesity research in occupational safety and health regarding the use of various obesity measurement and classification methods.

METHODS

A systematic search of the PubMed database on English language publications from 2000 to 2015 using related keywords and search of citations resulted in selection of 126 studies. They were categorized into two groups based on their main research question: 1) general physical or mental work-related functioning; and 2) task or body part specific functioning.

RESULTS

Regardless of the study group, body mass index (BMI) was the most frequently used measure. Over 63% of the studies relied solely on BMI to define obesity. In only 22% of the studies, body fat was directly measured by methods such as dual energy x-ray absorptiometry. Abdominal obesity was defined using waist circumference in recent years, and waist-hip ratio in earlier years. Inconsistent cut-offs have also been used across studies investigating similar topics.

CONCLUSIONS

Few authors acknowledged the limitations of using indirect obesity measures. This is in part due to the limited understanding of some occupational safety and health researchers regarding the complex issues surrounding obesity classification and also the mixed recommendations over the past 2-3 decades and across populations. Efforts need to be made to promote appropriate obesity measurement and reporting in this field.

Differential associations between dual-task walking abilities and usual gait patterns in healthy older adults-Results from the Baltimore Longitudinal Study of Aging

BACKGROUND

It is well established that facing a cognitive challenge while carrying out a motor task interferes with the motor task performance, and in general the ability of handling a dual-task declines progressively with aging. However, the reasons for this decline have not been fully elucidated. Understanding the association between usual-walking gait patterns and dual-task walking performance may provide new insights into the mechanisms that lead to gait deterioration in normal aging and its link to motor and cognitive function.

RESEARCH QUESTION

Our aim was to assess usual gait parameters in kinematics and kinetics to understand how these parameters are related with a specific task in dual-task walking.

METHODS

We hypothesized that difficulty in dual-task walking would be associated with gait deteriorations as reflected in range of motion and mechanical work expenditure. We tested this hypothesis by quantifying the gait of 383 participants in the Baltimore Longitudinal Study of Aging (68% of whom successfully completed the dual-task walk, 21% failed the motor task, and 11% failed the cognitive task).

RESULTS

Compared to successful performers, participants who failed the single motor task had slower gait speed, shorter stride length, higher cadence, and lower range of motion in the knee and ankle joints (p < 0.05, for all), while the participants who failed the cognitive task while walking had longer double support time (p = 0.003), and greater knee absorptive mechanical work (p = 0. 001) and lower ankle generative mechanical work (p < 0. 001).

SIGNIFICANCE

These results suggest that dual-task walking may be useful for monitoring subtle and diverse gait deteriorations in aging and possibly for designing interventions for maintaining and regaining proper gait patterns in older adults.

Dynamical Properties of Postural Control in Obese Community-Dwelling Older Adults †

Postural control is a key aspect in preventing falls. The aim of this study was to determine if obesity affected balance in community-dwelling older adults and serve as an indicator of fall risk. The participants were randomly assigned to receive a comprehensive geriatric assessment followed by a longitudinal assessment of their fall history. The standing postural balance was measured for 98 participants with a Body Mass Index (BMI) ranging from 18 to 63 kg/m², using a force plate and an inertial measurement unit affixed at the sternum. Participants' fall history was recorded over 2 years and participants with at least one fall in the prior year were classified as fallers. The results suggest that body weight/BMI is an additional risk factor for falling in elderly persons and may be an important marker for fall risk. The linear variables of postural analysis suggest that the obese fallers have significantly higher sway area and sway ranges, along with higher root mean square and standard deviation of time series. Additionally, it was found that obese fallers have lower complexity of anterior-posterior center of pressure time series. Future studies should examine more closely the combined effect of aging and obesity on dynamic balance.

Diet induced obesity alters muscle spindle afferent function in adult mice

Populations with obesity are more likely to fall and exhibit balance instability. The reason for this is likely multifactorial, but there is some evidence that sensory function is impaired during obesity. We tested the hypothesis that muscle proprioceptor function is compromised in a mouse model of diet induced obesity. An in vitro muscle-nerve preparation was used to record muscle spindle afferent responses to physiological stretch and sinusoidal vibration. We compared the responses of C57/Bl6 male and female mice on a control diet (10% kcal fat) with those eating a high fat diet (HFD; 60% kcal fat) for 10 weeks (final age 14–15 weeks old). Following HFD feeding, adult mice of both sexes exhibited decreased muscle spindle afferent responses to muscle movement. Muscle spindle afferent firing rates during the plateau phase of stretch were significantly lower in both male and female HFD animals as were two measures of dynamic sensitivity (dynamic peak and dynamic index). Muscle spindle afferents in male mice on a HFD were also significantly less likely to entrain to vibration. Due to the importance of muscle spindle afferents to proprioception and motor control, decreased muscle spindle afferent responsiveness may contribute to balance instability during obesity.

Socioeconomic status, non-communicable disease risk factors, and walking speed in older adults: multi-cohort population based study

OBJECTIVE

To assess the association of low socioeconomic status and risk factors for non-communicable diseases (diabetes, high alcohol intake, high blood pressure, obesity, physical inactivity, smoking) with loss of physical functioning at older ages.

DESIGN

Multi-cohort population based study.

SETTING

37 cohort studies from 24 countries in Europe, the United States, Latin America, Africa, and Asia, 1990-2017.

PARTICIPANTS

109 107 men and women aged 45-90 years.

MAIN OUTCOME MEASURE

Physical functioning assessed using the walking speed test, a valid index of overall functional capacity. Years of functioning lost was computed as a metric to quantify the difference in walking speed between those exposed and unexposed to low socioeconomic status and risk factors.

RESULTS

According to mixed model estimations, men aged 60 and of low socioeconomic status had the same walking speed as men aged 66.6 of high socioeconomic status (years of functioning lost 6.6 years, 95% confidence interval 5.0 to 9.4). The years of functioning lost for women were 4.6 (3.6 to 6.2). In men and women, respectively, 5.7 (4.4 to 8.1) and 5.4 (4.3 to 7.3) years of functioning were lost by age 60 due to insufficient physical activity, 5.1 (3.9 to 7.0) and 7.5 (6.1 to 9.5) due to obesity, 2.3 (1.6 to 3.4) and 3.0 (2.3 to 4.0) due to hypertension, 5.6 (4.2 to 8.0) and 6.3 (4.9 to 8.4) due to diabetes, and 3.0 (2.2 to 4.3) and 0.7 (0.1 to 1.5) due to tobacco use. In analyses restricted to high income countries, the number of years of functioning lost attributable to low socioeconomic status by age 60 was 8.0 (5.7 to 13.1) for men and 5.4 (4.0 to 8.0) for women, whereas in low and middle income countries it was 2.6 (0.2 to 6.8) for men and 2.7 (1.0 to 5.5) for women. Within high income countries, the number of years of functioning lost attributable to low socioeconomic status by age 60 was greater in the United States than in Europe. Physical functioning continued to decline as a function of unfavourable risk factors between ages 60 and 85. Years of functioning lost were greater than years of life lost due to low socioeconomic status and non-communicable disease risk factors.

CONCLUSIONS

The independent association between socioeconomic status and physical functioning in old age is comparable in strength and consistency with those for established non-communicable disease risk factors. The results of this study suggest that tackling all these risk factors might substantially increase life years spent in good physical functioning.

High-Velocity Quadriceps Exercises Compared to Slow-Velocity Quadriceps Exercises Following Total Knee Arthroplasty: A Randomized Clinical Study

BACKGROUND AND PURPOSE

Despite improvement in pain and perceived function in older adults following total knee arthroplasty (TKA), objective outcome measures of muscular impairment and ambulatory function demonstrate significant deficits. Evidence suggests that quadriceps power may play a greater role in ambulatory function than measures of strength alone following TKA. The purpose of this study was to compare the effect of high-velocity (HV) quadriceps exercises with that of slow-velocity (SV) quadriceps exercises on functional outcomes and quadriceps power following TKA.

METHODS

This study was a randomized clinical study conducted in an outpatient physical therapy clinic. Twenty-one participants who were 4 to 6 weeks post unilateral TKA were randomly assigned to an HV or SV group. Participants performed an evidence-based standardized progressive resistance exercise program in addition to HV quadriceps exercises or SV quadriceps exercises. Participants attended 2 sessions per week for 8 weeks. Before and after the 8-week exercise intervention, participants completed a functional questionnaire, health survey, functional testing, and underwent quadriceps strength and power testing.

RESULTS

Both groups demonstrated improvements in ambulatory outcome measures, strength, speed, and power. The HV group demonstrated significantly greater improvements in distance walked and quadriceps strength than the SV group.

LIMITATIONS

These data should be considered preliminary because of a small sample size.

CONCLUSION

HV quadriceps exercises may be an effective rehabilitation strategy in conjunction with a standardized progressive resistance exercise program beginning 4 to 6 weeks after TKA.

Reference values of gait using APDM movement monitoring inertial sensor system

Normal gait data reported show variability depending on specific equipment and techniques. Reference values of initial contact angle (ICA) and toe-off angle (TOA) are still lacking. We present a normative gait database of 292 healthy adults using the APDM Movement Monitoring inertial sensor system across a large age span of adulthood. Data were collected as participants completed a walk test for 2 min. Normalization was conducted and two factors were extracted by a factor analysis. Six reference gait variables under each factor were presented and the impacts of age, gender and BMI were evaluated by MANOVA and ANCOVA. ICA and TOA were highly correlated with speed and stride length. ICA was significantly larger in men, whereas larger TOA could be observed in women in all age groups but could not achieve significant difference. Overweight and obese adults walked at significantly lower speed, shorter stride length, reduced cadence and longer gait cycle duration. TOA was smaller in the obese group. However, the differences in ICA were not significant. Reference gait values described herein were valuable for identifying and interpreting gait phenomena using APDM®, contributing to rehabilitation of gait dysfunction.

POFBG-Embedded Cork Insole for Plantar Pressure Monitoring

We propose a novel polymer optical fiber (POF) sensing system based on fiber Bragg gratings (FBGs) to measure foot plantar pressure. The plantar pressure signals are detected by five FBGs, in the same piece of cyclic transparent optical polymer (CYTOP) fiber, which are embedded in a cork insole for the dynamic monitoring of gait. The calibration and measurements performed with the suggested system are presented, and the results obtained demonstrate the accuracy and reliability of the sensing platform to monitor the foot plantar pressure distribution during gait motion and the application of pressure. This architecture does not compromise the patient's mobility nor interfere in their daily activities. The results using the CYTOP fiber showed a very good response when compared with solutions using silica optical fibers, resulting in a sensitivity almost twice as high, with excellent repeatability and ease of handling. The advantages of POF (e.g., high flexibility and robustness) proved that this is a viable solution for this type of application, since POF's high fracture toughness enables its application in monitoring patients with higher body mass compared with similar systems based on silica fiber. This study has demonstrated the viability of the proposed system based on POF technology as a useful alternative for plantar pressure detection systems.

The influence of sex and obesity on gait biomechanics in people with severe knee osteoarthritis scheduled for arthroplasty

BACKGROUND

Sex and body mass may influence knee biomechanics associated with poor total knee arthroplasty (TKA) outcomes for knee osteoarthritis (OA). This study aimed to determine if gait differed between men and women, and overweight and class I obese patients with severe knee OA awaiting TKA.

METHODS

34 patients with severe knee OA (average age 70.0 (SD 7.2) years, body mass index 30.3 (4.1kg/m²)) were recruited from a TKA waiting list. Three-dimensional gait analysis was performed at self-selected walking speed. Comparisons were made between men and women, and overweight (body mass index (BMI) 25.0-29.9kg/m²) and class I obese (BMI 30.0-34.9kg/m²) participants. Biomechanical outcomes included absolute and body size-adjusted peak knee adduction moment (KAM), KAM impulse, peak knee flexion moment, as well as peak knee flexion and varus-valgus angles, peak varus-valgus thrust, and peak vertical ground reaction force (GRF).

FINDINGS

Men had a higher absolute peak KAM, KAM impulse and peak GRF compared to women, and this sex-difference in frontal plane moments remained after adjusting for body size. However, when additionally adjusting for static knee alignment, differences disappeared. Knee biomechanics were similar between obesity groups after adjusting for the greater body weight of those with class I obesity.

INTERPRETATION

Men had greater KAM and KAM impulse even after adjustment for body size; however adjustment for their more varus knees removed this difference. Obesity group did not influence knee joint kinematics or moments. This suggests sex- and obesity-differences in these variables may not be associated with TKA outcomes.

Age-Related Anabolic Resistance of Myofibrillar Protein Synthesis Is Exacerbated in Obese Inactive Individuals

CONTEXT

A diminished muscle anabolic response to protein nutrition may underpin age-associated muscle loss.

OBJECTIVE

To determine how chronological and biological aging influence myofibrillar protein synthesis (MyoPS).

DESIGN

Cross-sectional comparison.

SETTING

Clinical research facility.

PARTICIPANTS

Ten older lean [OL: 71.7 ± 6 years; body mass index (BMI) ≤25 kg ⋅ m-2], 7 older obese (OO: 69.1 ± 2 years; BMI ≥30 kg ⋅ m-2), and 18 young lean (YL) individuals (25.5 ± 4 years; BMI ≤25 kg ⋅ m-2).

INTERVENTION

Skeletal muscle biopsies obtained during a primed-continuous infusion of l-[ring-13C6]-phenylalanine.

MAIN OUTCOME MEASURES

Anthropometrics, insulin resistance, inflammatory markers, habitual diet, physical activity, MyoPS rates, and fiber-type characteristics.

RESULTS

Fat mass, insulin resistance, inflammation, and type II fiber intramyocellular lipid were greater, and daily step count lower, in OO compared with YL and OL. Postprandial MyoPS rates rose above postabsorptive values by ∼81% in YL (P < 0.001), ∼38% in OL (P = 0.002, not different from YL), and ∼9% in OO (P = 0.11). Delta change in postprandial MyoPS from postabsorptive values was greater in YL compared with OL (P = 0.032) and OO (P < 0.001). Absolute postprandial MyoPS rates and delta postprandial MyoPS change were associated with step count (r2 = 0.33; P = 0.015) and leg fat mass (r2 = 0.4; P = 0.006), respectively, in older individuals. Paradoxically, lean mass was similar between groups, and muscle fiber area was greater in OO vs OL (P = 0.002).

CONCLUSION

Age-related muscle anabolic resistance is exacerbated in obese inactive individuals, with no apparent detriment to muscle mass.

Influence of Body Mass Index on Sagittal Knee Range of Motion and Gait Speed Recovery 1-Year After Total Knee Arthroplasty

BACKGROUND

The purpose of this prospective study was to investigate the influence of body mass index (BMI) on gait parameters preoperatively and 1 year after total knee arthroplasty (TKA).

METHODS

Seventy-nine patients were evaluated before and 1 year after TKA using clinical gait analysis. The gait velocity, the knee range of motion (ROM) during gait, their gains (difference between baseline and 1 year after TKA), the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), quality of life, and patient satisfaction were assessed. Nonobese (BMI <30 kg/m²) and obese patients (BMI ≥30 kg/m²) were compared. Healthy controls were also assessed. Univariate and multivariate linear regression analyses were used to assess the association between gait speed and ROM gains. Adjustment was performed for gender, age, and WOMAC pain improvement.

RESULTS

At baseline, gait velocity and knee ROM were significantly lower in obese compared with those in the nonobese patients (0.99 ± 0.27 m/s vs 1.11 ± 0.18 m/s; effect size, 0.53; P = .021; and ROM, 41.33° ± 9.6° vs 46.05° ± 8.39°; effect size, 0.52; P = .022). Univariate and multivariate linear regressions did not show any significant relation between gait speed gain or knee ROM gain and BMI. At baseline, obese patients were more symptomatic than nonobese (WOMAC pain: 36.1 ± 14.0 vs 50.4 ± 16.9; effect size, 0.9; P < .001), and their improvement was significantly higher (WOMAC pain gain, 44.5 vs 32.3; effect size, 0.59; P = .011).

CONCLUSION

These findings show that all patients improved biomechanically and clinically, regardless of their BMI.

Six degree-of-freedom knee joint kinematics in obese individuals with knee pain during gait

Knee joint pain is a common symptom in obese individuals and walking is often prescribed as part of management programs. Past studies in obese individuals have focused on standing alignment and kinematics in the sagittal and coronal planes. Investigation of 6 degree-of-freedom (6DOF) knee joint kinematics during standing and gait is important to thoroughly understand knee function in obese individuals with knee pain. This study aimed to investigate the 6DOF knee joint kinematics in standing and during gait in obese patients using a validated fluoroscopic imaging system. Ten individuals with obesity and knee pain were recruited. While standing, the knee was in 7.4±6.3°of hyperextension, 2.8±3.3° of abduction and 5.6±7.3° of external rotation. The femoral center was located 0.7±3.1mm anterior and 5.1±1.5mm medial to the tibial center. During treadmill gait, the sagittal plane motion, i.e., flexion/extension and anterior-posterior translation, showed a clear pattern. Specifically, obese individuals with knee pain maintained the knee in more flexion and more anterior tibial translation during most of the stance phase of the gait cycle and had a reduced total range of knee flexion when compared to a healthy non-obese group. In conclusion, obese individuals with knee pain used hyperextension knee posture while standing, but maintained the knee in more flexion during gait with reduced overall range of motion in the 6DOF analysis.

Plantarflexor passive-elastic properties related to BMI and walking performance in older women

The objective of this study was to examine the influence of BMI on the passive-elastic properties of the ankle plantarflexors in older women. Twenty-three women, 65-80 yr, were separated into normal weight (NW, BMI <25.0kgm-2, n=11) and overweight-obese (OW, BMI≥25.0kgm-2, n=12) groups. Resistive torque of the ankle plantarflexors was recorded on an isokinetic dynamometer by passively moving the ankle into dorsiflexion. Stiffness, work absorption, and hysteresis were calculated across an ankle dorsiflexion angle of 10-15°. Maximal plantarflexor strength was assessed, then participants walked at maximal speed on an instrumented gait analysis treadmill while muscle activation (EMG) was recorded. Plantarflexor stiffness was 34% lower in OW (26.4±12.7Nmrad-1) than NW (40.0±15.7Nmrad-1, p=0.032). Neither work absorption nor hysteresis were different between OW and NW. Stiffness per kg was positively correlated to strength (r=0.66, p<0.001), peak vertical ground reaction force during walking (r=0.72, p<0.001), weight acceptance rate of force (r=0.51, p=0.007), push-off rate of force (r=0.41, p=0.026), maximal speed (r=0.61, p=0.001), and inversely correlated to BMI (r=-0.61, p=0.001), and peak plantarflexor EMG (r=-0.40, p=0.046). Older women who are OW have low plantarflexor stiffness, which may limit propulsive forces during walking and necessitate greater muscle activation for active force generation.

DIFERENCIAS ESPACIO-TEMPORALES DE LA LOCOMOCIÓN EN ADULTOS VARONES CON NORMOPESO Y SOBREPESO

RESUMEN Introducción: La obesidad ha estado relacionada con la presencia de adaptaciones estructurales y funcionales que provocan limitaciones en el control del movimiento. Objetivo: Determinar el efecto del exceso de peso sobre las variables espacio-temporales de la locomoción en varones jóvenes y activos. Métodos: Estudio de corte transversal de muestreo no probabilístico con 55 sujetos con normopeso (IMC ≤25) y 22 sujetos con sobrepeso (IMC >25). Se analizó el IMC, % de masa grasa, y el % de masa magra de ambos grupos con un bioimpedanciómetro multifrecuencia (Inbody 230). También se analizaron las variables cinemáticas de la locomoción utilizando una plataforma de presiones GaitRite. Resultados: El grupo con sobrepeso mostró una disminución significativa de la fase de oscilación y fase de apoyo monopodal (p <0,001) junto con un aumento de la fase de apoyo y fase de apoyo bipodal (p <0,001) comparado con el grupo normopeso. Conclusión: La reducción de la fase de oscilación y el incremento de la fase de apoyo y fase de apoyo bipodal que manifestaron el grupo con sobrepeso puede ser consecuencia del aumento de la inestabilidad que se produce durante la marcha debido al sobrepeso.

Effects of a Twelve-Week Weight Reduction Exercise Programme on Selected Spatiotemporal Gait Parameters of Obese Individuals

Objectives. This study was carried out to investigate the effects of twelve-week weight reduction exercises on selected spatiotemporal gait parameters of obese individuals and compare with their normal weight counterparts. Methods. Sixty participants (30 obese and 30 of normal weight) started but only 58 participants (obese = 30, normal weight = 28) completed the quasi-experimental study. Only obese group had 12 weeks of weight reduction exercise training but both groups had their walking speed (WS), cadence (CD), step length (SL), step width (SW), and stride length (SDL) measured at baseline and at the end of weeks 4, 8, and 12 of the study. Data were analysed using appropriate descriptive and inferential statistics. Results. There was significantly lower WS, SL, and SDL but higher CD and SW in obese group than the normal weight group at baseline and week 12. However, the obese group had significantly higher percentage changes in all selected spatiotemporal parameters than the normal weight group. Conclusion. The 12-week weight reduction exercise programme produced significantly higher percentage changes in all selected spatiotemporal gait parameters in the obese than normal weight individuals and is recommended for improvement of these parameters among the obese individuals with gait related problems.

Medidas temporoespaciais indicativas de quedas em mulheres saudáveis entre 50 e 70 anos avaliadas pela análise tridimensional da marcha

RESUMO Objetivou-se comparar e correlacionar medidas temporoespaciais da marcha indicativas de quedas. Participaram do estudo 35 mulheres saudáveis, sem histórico de quedas no ano da avaliação. A análise computadorizada tridimensional da marcha forneceu cinco medidas temporoespaciais de cada participante, dos membros inferiores direito (D) e esquerdo (E). A análise inferencial abordou dois grupos de mulheres: jovens (20 40 anos) e adultas-idosas (50-70 anos). Houve diferença estatística significativa entre os grupos para comprimento da passada D (p=0,003) e E (p=0,002); passo D (p=0,008) e E (p=0,001); tempo de apoio E (p=0,008); tempo de passo D (p=0,049); tempo de apoio duplo E (p=0,003); largura da base E (p=0,005); resposta à carga E (p=0,001); pré-balanço D (p=0,001) e E (p=0,001) e para algumas medidas em percentil do ciclo de marcha: apoio E (p=0,001); balanço E (p=0,001); apoio simples E (p=0,025); resposta à carga E (p=0,00); pré-balanço E (p=0,001) e pré-balanço D (p=0,014). A regressão linear indicou que a variação da idade modificou em média 18% as medidas de comprimento do passo e da passada e em 20% a velocidade da marcha. Com o avanço da idade, as medidas funcionais diminuíram; e, consequentemente, as medidas de estabilidade, como duração dos períodos de apoio, apoio duplo e pré-balanço, aumentaram. Essas modificações indicam risco de queda na faixa etária de 50 a 70 anos. Algumas medidas de marcha podem apresentar alteração em uma faixa etária ainda considerada de baixo risco.

The development of a charcot foot after significant weight loss in people with diabetes: three cautionary tales

Medication to aid weight loss and weight loss surgery are becoming more commonly available for people with diabetes. As a result of profound weight loss, diabetes may go into remission and many biochemical and physical parameters improve. However, some of the end organ damage associated with diabetes may not improve, peripheral neuropathy being an example. We present three cases in people with diabetes and pre-existing peripheral neuropathy who had lost significant weight. They became more mobile and developed a Charcot foot despite their diabetes improving significantly. People who have lost significant weight should continue to monitor their feet because the risks of foot disease remain even if diabetes goes into remission.

An exploratory investigation of changes in gait parameters with age in elderly Japanese women

BACKGROUND

The aim of the present study was to identify gait parameters in elderly Japanese women. 30 elderly women (65-74.9 years old) and 19 very elderly women (≥75 years old) participated in this study. A 3-dimensional (3D) motion analysis system was used to collect kinematic data, and a total of 70 gait parameters were analysed. Gait parameters included basic gait parameters, gait cycle parameters, and joints angle parameters, as well as angular velocity parameters, such as peak velocity and timing at the hip, knee, and ankle joints.

RESULTS

Our results indicated that basic gait parameters, such as the gait cycle, peak joint angle timing, and angular velocity parameters, significantly differ between elderly and very elderly women. Delayed peak joint angle timing and angular velocity parameters occurred during critical phases throughout the gait cycle: pre-swing, initial swing, and terminal swing phases.

CONCLUSIONS

Several gait parameters exhibited significant differences between elderly and very elderly women. The timing of the peak joint angle and angular velocity parameters are primary characteristics defining gait changes in the elderly.

Anthropometric, functional and foot trajectory determinants of stride length in self-reliant community-dwelling elderly persons in Talca, Chile

Abstract Objective: To analyze anthropometric, muscle performance and foot trajectory determinants of stride length (SL) during walking at a comfortable pace among self-reliant community-dwelling elderly persons in Talca, Chile. Method: A total of 63 self-reliant elderly persons participated in this observational and cross-sectional study. They were characterized by the anthropometric measures of mass, height and body mass index. Dorsiflexor muscle strength performance (DF-MS) and rate of force development were quantified. Finally, the elderly persons were asked to walk comfortably around a 40 meter elliptical circuit, using determined SL and maximum foot clearance (MaxFC) and minimum foot clearance (MFC) trajectory parameters. The SL determinants were evaluated by calculating the coefficient of determination (r2) considering a level of significance of p≤0.05. Results: The anthropometric variables demonstrated significant correlations (r>0.41) with the explanation of SL remaining incipient (r2<0.20). Muscle performance, meanwhile, was significantly correlated (r>0.52), with DF-MS standing out (r2=0.342). MaxFC represented a significant explanation for the data (r2=0.396), while the low correlation of MFC was not significant (r=0.24, r2=0.058). Conclusion: MaxFC and DF-MS are determinants of SL in self-reliant elderly Chileans. It is proposed that gait parameters could be normalized in accordance with trajectory and muscular performance.

Altered joint moment strategy during stair walking in diabetes patients with and without peripheral neuropathy

AIM

To investigate lower limb biomechanical strategy during stair walking in patients with diabetes and patients with diabetic peripheral neuropathy, a population known to exhibit lower limb muscular weakness.

METHODS

The peak lower limb joint moments of twenty-two patients with diabetic peripheral neuropathy and thirty-nine patients with diabetes and no neuropathy were compared during ascent and descent of a staircase to thirty-two healthy controls. Fifty-nine of the ninety-four participants also performed assessment of their maximum isokinetic ankle and knee joint moment (muscle strength) to assess the level of peak joint moments during the stair task relative to their maximal joint moment-generating capabilities (operating strengths).

RESULTS

Both patient groups ascended and descended stairs slower than controls (p<0.05). Peak joint moments in patients with diabetic peripheral neuropathy were lower (p<0.05) at the ankle and knee during stair ascent, and knee only during stair descent compared to controls. Ankle and knee muscle strength values were lower (p<0.05) in patients with diabetic peripheral neuropathy compared to controls, and lower at knee only in patients without neuropathy. Operating strengths were higher (p<0.05) at the ankle and knee in patients with neuropathy during stair descent compared to the controls, but not during stair ascent.

CONCLUSION

Patients with diabetic peripheral neuropathy walk slower to alter gait strategy during stair walking and account for lower-limb muscular weakness, but still exhibit heightened operating strengths during stair descent, which may impact upon fatigue and the ability to recover a safe stance following postural instability.

Chronic obstructive pulmonary disease phenotypes and balance impairment

BACKGROUND/OBJECTIVE

Chronic obstructive pulmonary disease (COPD) is a respiratory disease that results in airflow limitation and respiratory distress, also having many nonrespiratory manifestations that affect both function and mobility. Preliminary evidence suggests that balance deficits constitute an important secondary impairment in individuals with COPD. Our objective was to investigate balance performance in two groups of COPD patients with different body compositions and to observe which of these groups are more likely to experience falls in the future.

METHODS

We included 27 stable COPD patients and 17 healthy individuals who performed a series of balance tests. The COPD patients were divided in two groups: emphysematous and bronchitic. Patients completed the activities balance confidence scale and the COPD assessment test questionnaire and afterward performed the Berg Balance Scale, timed up and go, single leg stance and 6-minute walking distance test. We analyzed the differences in the balance tests between the studied groups.

RESULTS

Bronchitic COPD was associated with a decreased value when compared to emphysematous COPD for the following variables: single leg stance (8.7 vs 15.6; P<0.001) and activities balance confidence (53.2 vs 74.2; P=0.001). Bronchitic COPD patients had a significantly higher value of timed up and go test compared to patients with emphysematous COPD (14.7 vs 12.8; P=0.001).

CONCLUSION

Patients with COPD have a higher balance impairment than their healthy peers. Moreover, we observed that the bronchitic COPD phenotype is more likely to experience falls compared to the emphysematous phenotype.

Excess body weight and gait influence energy cost of walking in older adults

PURPOSE

The objective of this investigation is to study how excess body weight influences the energy cost of walking (Cw) and determine whether overweight and obese older adults self-select stride frequency to minimize Cw.

METHODS

Using body mass index (BMI), men and women between the ages of 65 and 80 yr were separated into normal weight (NW, BMI ≤24.9 kg·m(-2), n = 13) and overweight-obese groups (OWOB, BMI ≥25.0 kg·m(-2), n = 13). Subjects walked at 0.83 m·s on an instrumented treadmill that recorded gait parameters and completed three 6-min walking trials; at a preferred stride frequency (PSF), at +10% PSF, and at -10% PSF. Cw was determined by indirect calorimetry. Repeated-measures ANOVA was used to compare groups, and associations were tested with Pearson correlations, α = 0.05.

RESULTS

OWOB had 62% greater absolute Cw (301 ± 108 vs 186 ± 104 J·m, P < 0.001) and 20% greater relative Cw(kg) (3.48 ± 0.95 vs 2.91 ± 0.94 J·kg(-1)·m(-1), P = 0.046) than NW. Although PSF was not different between OWOB and NW (P = 0.626), Cw was 8% greater in OWOB at +10% PSF (P < 0.001). At PSF, OWOB spent less time in single-limb support (33.1% ± 1.5% vs. 34.9% ± 1.6 % gait cycle, P = 0.021) and more time in double-limb support (17.5% ± 1.6% vs 15.4% ± 1.4% gait cycle, P = 0.026) than NW. In OWOB, at PSF, Cw was correlated to impulse (r = -0.57, P = 0.027) and stride frequency (r = 0.51, P = 0.046).

CONCLUSIONS

Excess body weight is associated with greater Cw in older adults, possibly contributing to reduced mobility in overweight and obese older persons.

[Abdominal obesity mediates the association between a low physical activity and a decline in gait speed in community-dwelling elderly people: A cross-sectional study]

AIM

A low physical activity leads to obesity and a decline in the physical function. The aim of this cross-sectional study was to examine whether the association between a low physical activity and low physical function was mediated by obesity.

METHODS

A total of 73 community-dwelling elderly people participated in this study. The analysis included 56 participants without knee and hip osteoarthritis, low cognitive function (the Mini Mental State Examination score <24) and rheumatoid arthritis (mean age±SD: 73.3±4.1, female: 50%). The daily step count was collected as a measure of physical activity by a single axial accelerometer. The physical function was measured by the gait speed. Obesity was measured by the body mass index and waist circumference. To assess whether the association between the physical activity and physical function was mediated by obesity, linear regression models were fitted according to Baron and Kenny procedures for a mediation analysis. A p value <0.05 was considered to be statistically significant.

RESULTS

The body mass index did not act as a mediator in the association between the physical activity and gait speed, whereas the waist circumference acted as a full mediator in the association between the physical activity and gait speed.

CONCLUSION

An increased waist circumference mediates the association between a low physical activity and a low physical function in community-dwelling elderly people.

The relationship between foot arch measurements and walking parameters in children

BACKGROUND

Walking mechanics are influenced by body morphology. Foot arch height is one aspect of body morphology central to walking. However, generalizations about the relationship between arch height and walking are limited due to previous methodologies used for measuring the arch and the populations that have been studied. To gain the knowledge needed to support healthy gait in children and adults, we need to understand this relationship in unimpaired, typically developing children and adults using dynamic measures. The purpose of the current study was to examine the relationship between arch height and gait in a sample of healthy children and adults using dynamic measures.

METHODS

Data were collected from 638 participants (n = 254 children and n = 384 adults) at the Museum of Science, Boston (MOS) and from 18 4- to 8-year-olds at the Motor Development and Motor Control Laboratories. Digital footprints were used to calculate two arch indices: the Chippaux-Smirak (CSI) and the Keimig Indices (KI). The height of the navicular bone was measured. Gait parameters were captured with a mechanized gait carpet at the MOS and three-dimensional motion analyses and in-ground force plates in the Motor Development and Motor Control Laboratories.

RESULTS

Linear regression analyses on data from the MOS confirmed that as age increases, step length increases. With a linear mixed effect regression model, we found that individuals who took longer steps had higher arches as measured by the KI. However, this relationship was no longer significant when only adults were included in the model. A model restricted to children found that amongst this sample, those with higher CSI and higher KI values take longer relative step lengths. Data from the Motor Development and Motor Control Laboratories showed that both CSI and KI added to the prediction; children with lower anterior ground reaction forces had higher CSI and higher KI values. Arch height indices were correlated with navicular height.

CONCLUSIONS

These results suggest that more than one measure of the arch may be needed elucidate the relationship between arch height and gait.

"Feeling younger, walking faster": subjective age and walking speed in older adults

Walking speed is a key vital sign in older people. Given the implications of slower gait speed, a large literature has identified health-related, behavioral, cognitive, and biological factors that moderate age-related decline in mobility. The present study aims to contribute to existing knowledge by examining whether subjective age, how old or young individuals experience themselves to be relative to their chronological age, contributes to walking speed. Participants were drawn from the 2008 and 2012 waves of the Health and Retirement Study (HRS, N = 2970) and the 2011 and 2013 waves of the National Health and Aging Trends Study (NHATS, N = 5423). In both the HRS and the NHATS, linear regression analysis revealed that a younger subjective age was associated with faster walking speed at baseline and with less decline over time, controlling for age, sex, education, and race. These associations were partly accounted for by depressive symptoms, disease burden, physical activity, cognition, body mass index, and smoking. Additional analysis revealed that feeling younger than one's age was associated with a reduced risk of walking slower than the frailty-related threshold of 0.6 m/s at follow-up in the HRS. The present study provides novel and consistent evidence across two large prospective studies for an association between the subjective experience of age and walking speed of older adults. Subjective age may help identify individuals at risk for mobility limitations in old age and may be a target for interventions designed to mitigate functional decline.

Differences in physical function by body mass index in elderly Japanese individuals: The Fujiwara-kyo Study

OBJECTIVE

This study examined differences in physical function according to body mass index (BMI) in elderly Japanese individuals.

METHODS

Participants (1754 men and 1795 women aged ≥65 years) were divided into the following five BMI groups: low BMI (≤20.0), low-medium BMI (20.1-22.5), medium BMI (22.6-25.0), medium-high BMI (25.1-27.5) and high BMI (≥27.6). Physical function was measured according to BMI and sex, and associations between BMI and physical function were examined.

RESULTS

Compared with the medium BMI group, handgrip strength (HGS), knee extension torque (KET), and knee flexion torque (KFT) were significantly lower in both sexes in the low BMI group, while KET and KFT were significantly higher among men in the high BMI group. One-leg standing time (OLST) with open eyes was significantly shorter among men in the high BMI group than in the medium BMI group. The high BMI group was significantly inferior to the medium BMI group in 10m gait time (10MGT), OLST, and maximum one-step length to height ratio among women. All physical functions, except for 10MGT in men, were associated with BMI adjusted age and/or sex. Muscle strength showed a positive association with BMI in both sexes. There was a stronger association between BMI and physical performance in women compared to men.

CONCLUSION

We found that BMI influences a variety of factors related to muscle strength and physical performance. Our findings may help contribute to the prevention of mobility impairments in elderly Japanese individuals.

Sex-specific age associations of ankle proprioception test performance in older adults: results from the Baltimore Longitudinal Study of Aging

OBJECTIVES

this study was aimed to test the hypothesis that ankle proprioception assessed by custom-designed proprioception testing equipment changes with ageing in men and women.

METHODS

ankle proprioception was assessed in 289 participants (131 women) of the Baltimore Longitudinal Study of Aging (BLSA); the participants aged 51-95 years and were blinded during testing.

RESULTS

the average minimum perceived ankle rotation was 1.11° (SE = 0.07) in women and 1.00° (SE = 0.06) in men, and it increased with ageing in both sexes (P < 0.001, for both). Ankle tracking performance, which is the ability to closely follow with the left ankle, a rotational movement induced on the right ankle by a torque motor, declines with ageing in both men and women (P = 0.018 and P = 0.011, respectively).

CONCLUSIONS

a simple, standardised method for assessing ankle proprioception was introduced in this study using a customized test instrument, software and test protocol. Age-associated reduction in ankle proprioception was confirmed from two subtests of threshold and tracking separately for women and men. Findings in this study prompt future studies to determine whether these age-associated differences in the threshold for passive motion detection and movement tracking are evident in longitudinal study and how these specific deficits in ankle proprioception are related to age-associated chronic conditions such as knee or hip osteoarthritis and type II diabetes and affect daily activities such as gait.

Longitudinal effects of physical inactivity and obesity on gait speed in older adults with frequent knee pain: data from the Osteoarthritis Initiative

Physical inactivity (PI) and obesity are risk factors for many health conditions, including knee pain (KP). The purpose of the present study was to examine the 6-year effects of PI and obesity on gait speed (GS) among older adults with frequent KP. This prospective cohort study used data from the Osteoarthritis Initiative (OAI). At baseline, we studied 1788 adults aged 45 to 79 years old. We grouped the participants into four categories according to baseline scores on the Physical Activity Scale for the Elderly (PASE) and body mass index (BMI). GS was measured using the 20-m timed walk test. Frequent KP was assessed with a self-report questionnaire, and obesity was assessed by BMI (30 kg/m² or greater). General linear mixed models were conducted using data collected at baseline and 12, 24, 36, 48, and 72 months. After adjusting for all covariates, lower levels of physical activity and obesity were associated with a decrease in GS (β = -0.095, SE = 0.011, p < 0.0001). Our results suggest that both PI and obesity are associated with decreased GS over time in older adults with frequent KP.

Longitudinal changes in knee kinematics and moments following knee arthroplasty: a systematic review

BACKGROUND

Knee arthroplasty (KA) is recognized as an effective treatment of knee joint osteoarthritis and up to 90% of patients experience substantial pain relief. There has been no systematic review synthesizing the longitudinal changes in gait following KA. The aims of this systematic review were to determine the effects of KA on (i) frontal plane and (ii) sagittal plane kinematic and kinetic parameters during the stance phase of gait.

METHODS

MEDLINE (PubMed), CINAHL, SPORTdiscus (EBSCO), and Cochrane Library (Wiley) were searched until April 10th, 2014. 1,765 articles were identified, of which 19 studies describing 3-dimensional gait analysis pre- and post-KA were included. Study quality was evaluated by two reviewers independently using the Downs and Black checklist.

FINDINGS

Following KA, in the frontal plane, the maximum knee adduction angle and external knee adduction moment (KAM) tended to decrease. In the sagittal plane, findings suggest that the maximum knee flexion moment is increased. From the ten studies that included a healthy reference group, it was unclear whether gait variables returned to normal following KA.

INTERPRETATION

Overall, it appears that KA results in a decreased peak KAM and maximum knee adduction angles, an increased peak knee flexion moment and inconsistent changes in the peak knee flexion angle. Knowledge gaps remain due to methodological inconsistencies across studies, limited statistical analysis, and largely heterogeneous sample populations. More research is needed to determine whether KA restores gait patterns to normal, or if additional rehabilitation may be needed to optimize gait following surgery for osteoarthritis.

Size and shape differences in the distal femur and proximal tibia between normal weight and obese American Whites

This study tests for differences in articular and diaphyseal size and shape of the distal femur and proximal tibia between normal weight and obese individuals, and discusses the effects of obesity on the patterns of sexual dimorphism and secular change in the skeletal morphology of the knee. Measurements of the femur and tibia were recorded for 143 American White adult males and females born in the 20th century. The sample was divided into normal and obese weight categories based on the body mass index. Results show differences between normal weight and obese individuals in the size and shape of the femoral shaft and the medial side of the knee joint, none of which affect the pattern of sexual dimorphism. While changes in skeletal morphology associated with obesity may be observed in recent secular changes, its role is still unclear because of the relatively recent increase in obesity prevalence.

Obesity as a Factor Contributing to Falls by Older Adults

The growth of the worldwide population of older adults presents significant challenges, many inter-related, that range from the health of individuals to the health of national economies. In the US, more than one-third of older adults may be obese, a condition that may independently increase the risk for mobility impairment, fall-related injury and, possibly, costs of post-injury treatment and care. The effectiveness of conventional exercise-based fall prevention programs is significant but smaller than both the annual rate of falling of older adults and rate of growth of this population, who are at greatest risk for injurious falls. The anthropometric and functional consequences of obesity may impose limitations on the ability to perform compensatory stepping responses following large postural disturbances. The focus of this paper is the potential of task-specific training to improve compensatory stepping responses and reduce falls by obese people given the individual-specific anthropometric and functional consequences of obesity.

Combined effects of age and gender on gait symmetry and regularity assessed by autocorrelation of trunk acceleration

BACKGROUND

The gait of a healthy person is believed to be more regular and symmetrical than those of an individual with a disease. Thus, symmetry and regularity are important indicators of human gait.

METHODS

The effects of age and gender on gait symmetry and regularity were investigated in 87 Japanese participants by measuring trunk accelerometry during a 7-m walk. The younger group included 26 female and 21 male students, and the elderly group included 24 females and 16 males. Average age for each group was 20 and 70 years, respectively. Gait symmetry and regularity were evaluated on the basis of autocorrelation functions of trunk accelerations of vertical and anteroposterior axes.

RESULTS

The relationship between age and gait symmetry and regularity was statistically significant for both vertical and anteroposterior axes. Elderly participants showed lower symmetry and regularity in their gait than young participants. A significant gender effect was observed for the symmetry index of both axes but not for the regularity index. Male participants showed lower gait symmetry than females. An interaction effect between age and gender was significant in the symmetry index of anteroposterior acceleration. Gender effect was appeared more clearly in elderly than young participants.

CONCLUSION

Elderly participants showed a more asymmetrical and irregular gait than young participants. In addition to age, a significant gender effect was observed on gait symmetry. However, the effect size of gender was smaller than that of age, and it was not significant for gait regularity. The gait indices obtained by autocorrelation of trunk acceleration can be considered useful to evaluate aging effect on gait.

Influence of pressure-relief insoles developed for loaded gait (backpackers and obese people) on plantar pressure distribution and ground reaction forces

The aims of this study were to test the effects of two pressure relief insoles developed for backpackers and obese people on the ground reaction forces (GRF) and plantar pressure peaks during gait; and to compare the GRF and plantar pressures among normal-weight, backpackers, and obese participants. Based on GRF, plantar pressures, and finite element analysis two insoles were manufactured: flat cork-based insole with (i) corkgel in the rearfoot and forefoot (SLS1) and with (ii) poron foam in the great toe and lateral forefoot (SLS2). Gait data were recorded from 21 normal-weight/backpackers and 10 obese participants. The SLS1 did not influence the GRF, but it relieved the pressure peaks for both backpackers and obese participants. In SLS2 the load acceptance GRF peak was lower; however, it did not reduce the plantar pressure peaks. The GRF and plantar pressure gait pattern were different among the normal-weight, backpackers and obese participants.

In-shoe plantar pressures and ground reaction forces during overweight adults' overground walking

PURPOSE

Because walking is highly recommended for prevention and treatment of obesity and some of its biomechanical aspects are not clearly understood for overweight people, we compared the absolute and normalized ground reaction forces (GRF), plantar pressures, and temporal parameters of normal-weight and overweight participants during overground walking.

METHOD

A force plate and an in-shoe pressure system were used to record GRF, plantar pressures (foot divided in 10 regions), and temporal parameters of 17 overweight adults and 17 gender-matched normal-weight adults while walking.

RESULTS

With high effect sizes, the overweight participants showed higher absolute medial-lateral and vertical GRF and pressure peaks in the central rearfoot, lateral midfoot, and lateral and central forefoot. However, analyzing normalized (scaled to body weight) data, the overweight participants showed lower vertical and anterior-posterior GRF and lower pressure peaks in the medial rearfoot and hallux, but the lateral forefoot peaks continued to be greater compared with normal-weight participants. Time of occurrence of medial-lateral GRF and pressure peaks in the midfoot occurred later in overweight individuals.

CONCLUSIONS

The overweight participants adapted their gait pattern to minimize the consequences of the higher vertical and propulsive GRF in their musculoskeletal system. However, they were not able to improve their balance as indicated by medial-lateral GRF. The overweight participants showed higher absolute pressure peaks in 4 out of 10 foot regions. Furthermore, the normalized data suggest that the lateral forefoot in overweight adults was loaded more than the proportion of their extra weight, while the hallux and medial rearfoot were seemingly protected.

Greater Effect of Adiposity Than Physical Activity or Lean Mass on Physical Function in Community-Dwelling Older Adults

Adiposity, lean mass, and physical activity (PA) are known to influence physical function in older adults, although the independent influences are not completely characterized. Older adults (N= 156,Mage = 68.9 ± 6.7 yr, 85 men) were assessed for body composition via dual-energy X-ray absorptiometry, PA by accelerometer, and physical function via timed up-and-go (UP&GO), 30-s chair stand, 6-min walk (6-min WALK), and Star-Excursion Balance Test. In the absence of percentage-body-fat by PA interactions (p> .05), main effects existed such that a higher percentage body fat was associated with poorer performance in UP&GO, 30-s chair stand, and 6-min WALK (p< .05). No significant main effects were found for PA and functional performance. Adiposity explains 4.6–11.4% in physical functional variance (p< .05). Preventing increases in adiposity with age may help older adults maintain functional independence.

Effects of obesity on functional capacity

OBJECTIVE

To assess the relationships between BMI and walking speed, balance control, sit-to-stand performance (a measure of mass specific lower limb power), and endurance.

DESIGN AND METHODS

Thirty-six women with a BMI ≥ 30 kg/m(2) and 10 women with normal body weight (BMI between 18 kg/m(2) and 25 kg/m(2) ) were enrolled in this observational study. The obese group comprised 12 persons with a BMI ≥ 30 and <35 (obese), 14 subjects with a BMI ≥ 35 and <40 (severe obesity) and 10 people with a BMI ≥ 40 kg/m(2) (morbid obesity). All subjects underwent a clinical examination, a gait test, an endurance test (6 minutes walking test), a mass specific lower limb power test (five times sit-to-stand) and a balance test.

RESULTS

Obese women exhibited slower fast gait speeds (P < 0.05) with correspondingly shorter stride lengths, poorer sit-to-stand performance (P < 0.05), and endurance (P < 0.05). However, once the state of severe obesity was reached, additional weight gain (morbid obesity) does not seem to decrease these functional capacities any further.

CONCLUSION

This study underlines the importance of assessing obese patients' related physical problems in an early stage of obesity in order to focus exercise regimens and promote appropriate health behaviors.

The relationship between increased body mass index and frailty on falls in community dwelling older adults

Background

The global population is becoming older and more overweight. The inter-relationship between frailty and falls is often seen in the older adult and is associated with poor health outcomes. Little is known about this relationship for those with excess body mass. This study aimed to assess the relationships between BMI, frailty and falls.

Methods

Frailty, body mass index, clinical and demographic characteristics were assessed at baseline for 606 community dwelling adults aged 60 years and older. Falls were assessed prospectively with a semi-structured telephone interview two years later.

Results

An increase in BMI contributed significantly to the identification of frail (Odds Ratio: 4.4; 95% Confidence Interval: 1.4, 13.6) older adults. A total of 346 falls by 148 participants were reported at follow up. Those with an increased BMI were significantly less likely to have experienced a fall between baseline and follow up assessments (p = 0.03). Despite these opposing trends a BMI greater than or equal to 30.0 kg.m² did not alter the relationship between falls and frailty for the current cohort.

Conclusions

This is the first study to assess the falls-frailty relationship for those with an increased BMI. Obesity was found to be protective against falling but not specifically in frail older adults.

Evaluation of cardiorespiratory fitness and respiratory muscle function in the obese population

Cardiorespiratory fitness (CRF) is one of the most important health metrics in apparently healthy individuals, those at increased risk for cardiovascular (CV) disease and virtually all patient populations. In addition to CRF, a host of other variables obtained from aerobic exercise testing provides clinically valuable information. Individuals classified as obese (i.e. a body mass index ≥30 kg/m(2)) have varying degrees of CV, pulmonary and skeletal muscle dysfunction that impact CRF and other key aerobic exercise testing variables. Moreover, there is now evidence indicating inspiratory and expiratory respiratory muscle function, even in the absence of interstitial lung disease, is potentially compromised as a result of obesity. When obesity-induced respiratory muscle dysfunction is present, it has the potential to contribute to the limitations in CRF. The current review will discuss aerobic exercise testing and the assessment of respiratory muscle function in the obese population.