Effects of computer-aided rowing exercise systems on improving muscle strength and function in older adults with mild knee osteoarthritis: a randomized controlled clinical trial.

BACKGROUND: Osteoarthritis (OA) is common in aged adults and can result in muscle weakness and function limitations in lower limbs. Knee OA affects the quality of life in the elderly. Technology-supported feedback to achieve lower impact on knee joints and individualized exercise could benefit elderly patients with knee OA. Herein, a computer-aided feedback rowing exercise system is proposed, and its effects on improving muscle strength, health conditions, and knee functions of older adults with mild knee OA were investigated. METHODS: Thirty-eight older adults with mild knee OA and satisfying the American College of Rheumatology (ACR) clinical criteria participated in this randomized controlled clinical trial. Each subject was randomly assigned to a computer-aided rowing exercise (CRE) group (n = 20) or a control group (CON) (n = 18) that received regular resistance exercise programs two times per week for 12 weeks. Outcome measurements, including the Western Ontario and MacMaster Universities (WOMAC), muscle strength and functional fitness of the lower limbs, were evaluated before and after the intervention. RESULTS: Participants' functional fitness in the CRE group exhibited significantly higher adjusted mean post-tests scores, including the WOMAC (p = 0.006), hip abductors strength (kg) (MD = 2.36 [1.28, 3.44], p = 5.67 × 10-5), hip adductors strength (MD = 3.04 [1.38, 4.69], p = 0.001), hip flexors strength (MD = 4.01 [2.24, 5.78], p = 6.46 × 10-5), hip extensors strength (MD = 2.88 [1.64, 4.12], p = 4.43 × 10-5), knee flexors strength (MD = 2.03 [0.66, 3.41], p = 0.005), knee extensors strength (MD = 1.80 [0.65, 2.94], p = 0.003), and functional-reach (cm) (MD = 3.74 [0.68, 6.80], p = 0.018), with large effect sizes (η2 = 0.17-0.42), than those in the CON group after the intervention. CONCLUSIONS: Older adults with knee OA in the CRE group exhibited superior muscle strength, health conditions, and functional fitness improvements after the 12-week computer-aided rowing exercise program than those receiving the conventional exercise approach. TRIAL REGISTRATION: The Institutional Review Board of the Taipei Medical University approved the study protocol (no. N201908020, 27/05/2020) and retrospectively registered at ClinicalTrials.gov (trial registry no. NCT04919486, 09/06/2021).

The impact of aging and reaching movements on grip stability control during manual precision tasks.

BACKGROUND: Operating an object by generating stable hand-grip force during static or dynamic posture control of the upper extremities simultaneously is an important daily activity. Older adults require different attentional resources during grip strength control and arm movements. However, the impact of aging and reaching movements on precise grip strength and stability control among older adults is not well understood. This study investigated the impact of aging and reaching movements on grip strength and stability control in both hands of the upper extremities. METHODS: Fifty healthy young adults (age: 28.8 ± 14.0 years) and 54 healthy older adults (73.6 ± 6.3 years) were recruited to perform isometric grip strength test at 20% maximal voluntary contraction as the target force during three manual precision tasks simultaneously: stationary task (without arm movements), forward-reach task, and backward-reach task. The average grip force (in kg) and coefficient of variation values (expressed as a percentage) during manual precision tasks were calculated to determine the quality of participants' grip strength. The deviation error, absolute error, and force-stability index values were calculated to determine the strength control relative to the target force. RESULTS: For both the young and older groups, the force-stability index values in both hands were significantly higher during forward- and backward-reaching movements than in the stationary condition (p < 0.05). The older group exhibited a significantly lower hand-grip strength and stability of strength control in both hands than the young group (p < 0.05). CONCLUSIONS: Aging and reaching task performance reduced the grip strength of participants and increased the variations in strength control of both hands relative to the target force, indicating that older adults exhibit poor grip strength and stability control when performing arm-reaching movements. These findings may help clinical therapists in establishing objective indexes for poor grip-stability control screening and developing appropriate rehabilitation programs or health-promotion exercises that can improve grip strength and stability control in older people.

Impacts of tai chi exercise on functional fitness in community-dwelling older adults with mild degenerative knee osteoarthritis: a randomized controlled clinical trial.

BACKGROUND: Degenerative osteoarthritis (OA) often leads to pain and stiffness of the affected joints, which may affect the physical performance and decrease the quality of life of people with degenerative knee OA. Compared to traditional exercise, tai chi is a safe exercise with slow movements which can facilitate physical functioning and psychological well being, and might be suitable for improving the physical activities of older adults with knee OA. Therefore, this study investigated the impacts of tai chi exercise on the functional fitness of community-dwelling older adults with degenerative knee OA. METHODS: Sixty-eight community-dwelling older adults with knee OA were recruited from the local community to participate in this randomized controlled clinical trial. All subjects were randomly assigned to either an TCE group that practiced tai chi exercise (TCE) (n = 36) or a control group (CON) (n = 32) that received regular health education programs twice per week for 12 weeks. Outcome measurements were determined using functional fitness tests before and after the intervention, including a 30-s chair stand (number of repeats), 30-s arm-curl (number of repeats), 2-min step (number of steps), chair sit-and-reach (reaching distance, cm), back-scratch flexibility (distance between hands, cm), single-leg stand (time, s), functional reach (reaching distance, cm), 8-foot up-and-go (time, s), and 10-m walk tests (time, s). Pre-post comparisons of functional fitness were analyzed using the ANCOVA test with SPSS software version 18.0. RESULTS: Results revealed that participants' functional fitness in the TCE group had significantly higher adjusted mean post-tests scores than that in the CON group after the intervention, including the 8-foot up-and-go (s) (mean difference [MD]=-2.92 [-3.93, -1.91], p = 2.39*10- 7), 30-s arm curl (MD = 4.75 (2.76, 6.73), p = 1.11*10- 5), 2-min step (MD = 36.94 [23.53, 50.36], p = 7.08*10- 7), 30-s chair stand (MD = 4.66 [2.97, 6.36], p = 6.96*10- 7), functional-reach (MD = 5.86 [3.52, 8.20], p = 4.72*10- 6), single-leg stand with eyes closed (MD = 3.44 [1.92, 4.97], p = 2.74*10- 5), chair sit-and-reach (MD = 3.93 [1.72, 6.15], p = 0.001), and single-leg stand with eyes opened (MD = 17.07 [6.29, 27.85], p = 0.002), with large effect sizes (η²=0.14 ~ 0.34). CONCLUSIONS: Community-dwelling older adults with knee OA in the TCE group had better functional fitness performances after the 12-week tai chi intervention than those receiving only health education.

Impacts of Stroke on Muscle Perceptions and Relationships with the Motor and Functional Performance of the Lower Extremities.

Stroke results in paretic limb disabilities, but few studies have investigated the impacts of stroke on muscle perception deficits in multiaxis movements and related functional changes. Therefore, this study aimed to investigate stroke-related changes in muscle perceptions using a multiaxis ankle haptic interface and analyze their relationships with various functions. Sixteen stroke patients and 22 healthy participants performed active reproduction tests in multiaxis movements involving the tibialis anterior (TA), extensor digitorum longus (EDL), peroneus longus, and flexor digitorum longus (FDL) of the ankle joint. The direction error (DE), absolute error (AE), and variable error (VE) were calculated. The lower extremity of Fugl-Meyer Assessment (FMA-LE), Barthel Index (BI), Postural Assessment Scale for Stroke Patients, Tinetti Performance-Oriented Mobility Assessment (POMA), and 10-m walk test (10MWT) were evaluated. VE of EDL for the paretic ankle was significantly lower than that for the nonparetic ankle (p = 0.009). AE of TA, EDL, and FDL and VE of EDL and FDL of muscle perceptions were significantly lower in healthy participants than in stroke patients (p < 0.05 for both). DE of TA for the paretic ankle was moderately correlated with FMA-LE (r = -0.509) and POMA (r = -0.619) scores. AE and VE of EDL for the paretic ankle were moderately correlated with the 10MWT score (r = 0.515 vs. 0.557). AE of FDL for the paretic ankle was also moderately correlated with BI (r = -0.562). This study indicated poorer accuracy and consistency in muscle perception for paretic ankles, which correlated with lower limb functions of stroke patients.

Bimanual coordination deficits in hands following stroke and their relationship with motor and functional performance.

BACKGROUND: Stroke can lead to movement disorders that affect interlimb coordination control of the bilateral upper extremities, especially the hands. However, few studies have investigated the influence of a stroke on bimanual force coordination control between the hands using a quantitative measurement tool, or the relationship of force coordination with paretic upper extremity motor and functional performance. We aimed to investigate these outcomes using a novel measurement device, and analyze the relationship of bimanual force coordination control deficits in both hands with motor and functional performances of the paretic upper extremity in stroke patients. METHODS: Sixteen healthy adults and 22 stroke patients were enrolled. A novel bilateral hand grip measurement device with two embedded dynamometers was used to evaluate the grip force during a bilateral hand grip-force coordination control task. The alternating time and force applied for coordination with the grip force of both hands were calculated to analyze control of bimanual grip force coordination. Motor and functional measurements included the upper-extremity portion of the Fugl-Meyer assessment (FMA-UE), Wolf Motor Function Test (WMFT), Motor Assessment Scale (MAS), and Barthel Index (BI). RESULTS: Compared with the healthy group, the alternating time from the non-paretic to the paretic hand was 27.6% shorter for stroke patients (p < 0.001). The grip force generated for coordination in the healthy group was significantly greater (30-59%) than that of the stroke group (p < 0.05), and the coefficients of variation of alternating time (p = 0.001) and force applied (p = 0.002) were significantly higher in the stroke group than the healthy group. The alternating time from the paretic to the non-paretic hand showed moderately significant correlations with the FMA-UE (r = - 0.533; p = 0.011), the WMFT (r = - 0.450; p = 0.036), and the BI (r = - 0.497; p = 0.019). CONCLUSIONS: Stroke results in a decline in bimanual grip force generation and increases the alternating time for coordinating the two hands. A shorter alternating time is moderately to highly associated with enhanced motor and functional performances.

Chronic low back pain is associated with impaired bed turning ability: Evaluation by a mobility detection system.

BACKGROUND: We aimed to assess and compare kinetics and kinematic variables of bed turning ability using a mobility detection system in patients with and without chronic low back pain and to observe the impacts of the disease on bed turning kinetics and kinematics. METHODS: Thirty-five patients with chronic low back pain were enrolled and compared to healthy controls (n = 34). Pain scores and disability level were assessed by Numeric Pain Rating Scale and the function questionnaires including Oswestry Disability Index and Roland Morris Disability Questionnaire. Bed turning ability was tested using the Mobile Detection System. Univariate and multivariate regression analysis were applied to compare the differences between groups. FINDINGS: Patients with chronic low back pain had significantly lower turning over and back force/weight ratio (p < 0.001) than those healthy controls. Turning over time was significantly longer in patients with Numeric Rating Scale score 3 than in those with Numeric Rating Scale score 2 (p = 0.015). Turning over and back force were significantly higher in male patients and patients with higher BMI after adjusting BMI and sex, respectively (all p < 0.001). When turning back, chronic low back pain patients with Numeric Rating Scale scores of 3 had lower turning back force/weight ratio than those with Numeric Rating Scale scores of 2 (p = 0.014). Male patients had higher turning back force/weight ratio after adjusting pain score (p = 0.001). INTERPRETATION: The novel Mobility Detection System can provide more objective assessments of bed turning kinetics and kinematics in patients with chronic low back pain.

Validation of Vibration Exercises on Enhancing Muscle Strength and Upper Limb Functionality among Pre-Frail Community-Dwelling Older Adults.

Pre-frail older adults require appropriate exercise to enhance muscle strength as well as upper limb functionality. We developed a handheld vibrator and evaluated its effectiveness in enhancing muscle strength compared to conventional exercises among pre-frail community-dwelling older adults. Thirty-one pre-frail older adults (aged 75.5 ± 5.1 years) were recruited and randomly allocated to a vibration group (VG) and control group (CG). The VG underwent 20 minutes of vibration (frequency: 30 Hz, amplitude: 5 mm, horizontal vibration) using a handheld vibrator as well as 40 minutes of conventional exercise. The CG received 60 minutes of conventional exercise only. The primary outcome was muscle strength assessment (kg), and the secondary outcome included activities of daily living and instrumental activities of daily living scores. The comparisons between the outcome measures revealed no significant differences at the baseline level. Muscle strength of the dominant (ß = 2.49, p = 0.002) and non-dominant (ß = 1.89, p = 0.02) wrist flexion, brachioradialis (ß = 3.8, p = 0.01), and biceps brachii (ß = 3.02, p = 0.02) in the dominant upper limbs was significantly increased among the VG. The vibration intervention can enhance muscle strength in the upper limbs among pre-frail older adults.

Analysis of Vibration Frequency and Direction for Facilitating Upper-Limb Muscle Activity.

We aimed to determine the effect of vibration frequency and direction on upper-limb muscle activation using a handheld vibrator. We recruited 19 healthy participants who were instructed to hold a handheld vibrator in their dominant hand and maintain the elbow at 90° flexion, while vertical and horizontal vibrations were applied with frequencies of 15, 30, 45, and 60 Hz for 60 s each. Surface electromyography (EMG) measured the activities of the flexor digitorum superficialis (FDS), flexor carpi radialis (FCR), extensor carpi ulnaris (ECU), extensor carpi radialis (ECR), biceps, triceps, and deltoid anterior muscles. EMG changes were evaluated as the difference in muscle activity between vibration and no-vibration (0 Hz) conditions. Muscle activity was induced under vibration conditions in both vertical and horizontal (p < 0.05) directions. At 45 Hz, FDS and FCR activities increased during horizontal vibrations, compared with those during vertical vibrations. ECU activity significantly increased under 15-Hz vertical vibrations compared with that during horizontal vibrations. Vibrations from the handheld vibrator significantly induced upper-limb muscle activity. The maximum muscle activations for FDS, ECR, ECU, biceps, and triceps were induced by 45-Hz horizontal vibration. The 60-Hz vertical and 30-Hz horizontal vibrations facilitated maximum muscle activations for the FCR and deltoid anterior, respectively.

Validating the Capability for Measuring Age-Related Changes in Grip-Force Strength Using a Digital Hand-Held Dynamometer in Healthy Young and Elderly Adults.

BACKGROUND: Grip-force performance can be affected by aging, and hand-grip weakness is associated with functional limitations of dasily living. However, using an appropriate digital hand-held dynamometer with continuous hand-grip force data collection shows age-related changes in the quality of hand-grip force control may provide more valuable information for clinical diagnoses rather than merely recording instantaneous maximal hand-grip force in frail elderly adults or people with a disability. Therefore, the purpose of this study was to indicate the construct validity of the digital MicroFET3 dynamometer with Jamar values for maximal grip-force assessments in elderly and young adults and confirmed age-related changes in the maximal and the quality of grip-force performance using the MicroFET3 dynamometer in elderly people. METHODS: Sixty-five healthy young (23.3 ± 4.5 years) and 50 elderly (69.5 ± 5.8 years) adults were recruited and asked to perform a validity test of the grip-force maximum voluntary contraction (MVC) using both the dominant and nondominant hands with a Jamar dynamometer and a MicroFET3 dynamometer. RESULTS: A strong correlation of maximal grip-force measurements was found between the MicroFET3 dynamometer and Jamar standard dynamometer for both hands in all participants (p < 0.05). Although, the results showed that a lower grip force was measured in both hands by the MicroFET3 dynamometer than with the Jamar dynamometer by 49.9%~57% (p < 0.05), but confidently conversion formulae were also developed to convert MicroFET3 dynamometer values to equivalent Jamar values for both hands. Both dynamometers indicated age-related declines in the maximum grip-force performance by 36.7%~44.3% (p < 0.05). We also found that the maximal hand-grip force values generated in both hand by the elderly adults were slower and more inconsistent than those of the young adults when using the MicroFET3 dynamometer. CONCLUSIONS: This study demonstrated that the digital MicroFET3 dynamometer has good validity when used to measure the maximal grip force of both hands, and conversion formulae were also developed to convert MicroFET3 dynamometer force values to Jamar values in both hands. Comparing with the Jamar dynamometer for measuring grip force, the MicroFET3 dynamometer not only indicated age-related declines in the maximum grip-force performance but also showed slower and more inconsistent maximal hand-grip strength generation by the elderly.

Inhibition of autophagy protects against sepsis by concurrently attenuating the cytokine storm and vascular leakage.

OBJECTIVES: Sepsis is an overwhelming systemic inflammatory response for which no satisfactory therapeutic drug is available. Previous studies have shown that autophagy is involved in the cytokine storm and vascular leakage that occur during sepsis. Therefore, we aimed to evaluate the therapeutic potential of autophagy inhibitors against bacterial infection-induced sepsis. METHODS: Cytokine production and phagocytosis of bacteria by human leukocytes and the permeability of endothelial cells were determined after the co-incubation of cells with lipopolysaccharide (LPS) or Escherichia coli in the presence or absence of autophagy inhibitors in vitro. Furthermore, the therapeutic effects of the autophagy inhibitors in E. coli-infected mice were analysed. RESULTS: In the presence of the autophagy inhibitors, the LPS-triggered cytokine secretion of human leucocytes and LPS (or LPS-conditioned medium from leucocytes)-induced endothelial hyperpermeability were significantly reduced. Moreover, the inhibition of autophagy enhanced the clearance of E. coli by leucocytes in vitro. Finally, we demonstrated that post-treatment but not pretreatment with an autophagy inhibitor (hydroxychloroquine) completely protected mice against E. coli infection-induced lethality by simultaneously reducing cytokine production and vascular leakage and enhancing bacterial clearance. CONCLUSIONS: These results suggest that autophagy plays an important role in the pathogenesis of sepsis and could serve as a potential therapeutic target for sepsis.

Influence of aging and visual feedback on the stability of hand grip control in elderly adults.

Aging causes a gradual decrease in maximal grip strength and leads many elderly people to have to rely on visual feedback to compensate for poorer muscle strength in performing daily activities and preventing accidents. Previous studies have investigated age and visual feedback-related changes in grip strength. However, little is known about methods of determining the quality and stability of hand grip strength control in the elderly, which is important for understanding their ability to generate grip force when handling objects with and without visual feedback in daily living. Therefore, the purpose of this study was to investigate the influence of aging and visual feedback on the stability of hand grip control in both hands in elderly adults. Forty-four healthy elderly persons (age 80.5 ±â€¯4.53 years) and 36 young adults (age 32.69 ±â€¯16.48 years) were recruited to execute grip force stability tasks using both hands at a 2 kg target force level. To perform the grip force stability task, the participants were asked to hold the dynamometer tightly in an attempt to achieve the target force level under visual and non-visual feedback conditions. Strength performances (grip force and coefficient of variation values) and stability of strength control (deviation error, variation error and force stability index values) for hand grip force stability tasks were calculated and analyzed. Compared with the visual feedback condition, the stability of grip force control in the hands of the young and elderly groups were significantly reduced in the non-visual feedback condition by 23.5%-57.1% (p < .05). The elderly group also showed significantly worse hand grip strength performances and stability of hand strength control than the young adult group (p < .05). Aging and non-visual feedback reduced the hand grip force output and stability of grip strength control of the hands. This may reveal the difficulty with manipulating hand-held objects in the absence of visual feedback while performing activities of daily living among the elderly.

Analysis of trunk rolling in Parkinson's disease patients using a mattress mobility detection system.

BACKGROUND AND OBJECTIVE: Parkinson's disease (PD) is a neurodegenerative condition characterized by motor dysfunction and various types of non-motor impairments. The reaction time and movement time are reported to become more severe delayed in worse PD patients. Most tools for evaluating motor impairment are limited by relying on subjective observations and being qualitative in design. The aim of this study was to investigate trunk rolling performance in PD patients by using a recently developed system to detect turning in bed. METHODS: The study included 20 PD patients and 42 healthy controls. A mattress mobility detection system was employed for quantitative measurements. Each test session consisted of subjects starting by lying in a supine position on a bed and rolling 10 times onto their left side and 10 times onto their right side. Strain gauges mounted under the feet of the bed recorded changes in the center of pressure (CoP). RESULTS: For turning back, the patients compared with the controls had significantly longer movement time (P = 0.017), longer time to peak counteraction (P = 0.001), larger ratio of peak counteraction to movement time (P = 0.006), shorter CoP displacement (P < 0.0001), slower turning speed (P = 0.000), weaker peak counteraction (P = 0.013), and smaller ratio of peak counteraction to weight (P = 0.032). Results for turning over were similar except there was no significant difference in the ratio of peak counteraction to weight. CONCLUSIONS: The mattress mobility detection system was useful for objectively assessing trunk rolling performance of PD patients. Improved assessment of trunk function in PD patients could lead to better treatments and improved rehabilitation procedures.

Development and clinical application of a computer-aided real-time feedback system for detecting in-bed physical activities.

BACKGROUND AND OBJECTIVE: Being bedridden long-term can cause deterioration in patients' physiological function and performance, limiting daily activities and increasing the incidence of falls and other accidental injuries. Little research has been carried out in designing effective detecting systems to monitor the posture and status of bedridden patients and to provide accurate real-time feedback on posture. The purposes of this research were to develop a computer-aided system for real-time detection of physical activities in bed and to validate the system's validity and test-retest reliability in determining eight postures: motion leftward/rightward, turning over leftward/rightward, getting up leftward/rightward, and getting off the bed leftward/rightward. METHODS: The in-bed physical activity detecting system consists mainly of a clinical sickbed, signal amplifier, a data acquisition (DAQ) system, and operating software for computing and determining postural changes associated with four load cell sensing components. Thirty healthy subjects (15 males and 15 females, mean age = 27.8 ± 5.3 years) participated in the study. All subjects were asked to execute eight in-bed activities in a random order and to participate in an evaluation of the test-retest reliability of the results 14 days later. Spearman's rank correlation coefficient was used to compare the system's determinations of postural states with researchers' recordings of postural changes. The test-retest reliability of the system's ability to determine postures was analyzed using the interclass correlation coefficient ICC(3,1). RESULTS: The system was found to exhibit high validity and accuracy (r = 0.928, p < 0.001; accuracy rate: 87.9%) in determining in-bed displacement, turning over, sitting up, and getting off the bed. The system was particularly accurate in detecting motion rightward (90%), turning over leftward (83%), sitting up leftward or rightward (87-93%), and getting off the bed (100%). The test-retest reliability ICC(3,1) value was 0.968 (p < 0.001). CONCLUSIONS: The system developed in this study exhibits satisfactory validity and reliability in detecting changes in-bed body postures and can be beneficial in assisting caregivers and clinical nursing staff in detecting the in-bed physical activities of bedridden patients and in developing fall prevention warning systems.

Validity of an ankle joint motion and position sense measurement system and its application in healthy subjects and patients with ankle sprain.

BACKGROUND AND OBJECTIVE: Ankle motion and proprioception in multiple axis movements are crucial for daily activities. However, few studies have developed and used a multiple axis system for measuring ankle motion and proprioception. This study was designed to validate a novel ankle haptic interface system that measures the ankle range of motion (ROM) and joint position sense in multiple plane movements, investigating the proprioception deficits during joint position sense tasks for patients with ankle instability. METHODS: Eleven healthy adults (mean ± standard deviation; age, 24.7 ± 1.9 years) and thirteen patients with ankle instability were recruited in this study. All subjects were asked to perform tests to evaluate the validity of the ankle ROM measurements and underwent tests for validating the joint position sense measurements conducted during multiple axis movements of the ankle joint. Pearson correlation was used for validating the angular position measurements obtained using the developed system; the independent t test was used to investigate the differences in joint position sense task performance for people with or without ankle instability. RESULTS: The ROM measurements of the device were linearly correlated with the criterion standards (r = 0.99). The ankle instability and healthy groups were significantly different in direction, absolute, and variable errors of plantar flexion, dorsiflexion, inversion, and eversion (p < 0.05). CONCLUSIONS: The results demonstrate that the novel ankle joint motion and position sense measurement system is valid and can be used for measuring the ankle ROM and joint position sense in multiple planes and indicate proprioception deficits for people with ankle instability.

Analysis of Trunk Rolling Performances by Mattress Mobility Detection System in Poststroke Patients: A Pilot Study.

PURPOSE: The purpose of this study was to investigate the correlation of kinematic variables with quality of trunk control in poststroke patients. METHODS: This cross-sectional study included stroke subjects with mild to moderate motor deficit corresponding to Brunnstrom stages 3-4. Trunk functional performance was measured using bed mobility monitor system. All tasks were repeated ten times for both directions in each subject. Outcome measurements included the movement time and displacement of center of pressure (CoP) from supine to side lying and returning. RESULTS: The results revealed that a significant longer turning time was observed when turning from the paretic side toward the nonparetic side compared to the other direction, with an estimated mean difference of 0.427 sec (P = 0.005). We found a significant difference in the time of rolling back to supine position between two directions. The displacement of CoP in rolling back from side lying on the nonparetic side was smaller than that from the paretic side with an estimated mean difference of -0.797 cm (P = 0.023). CONCLUSIONS: The impaired trunk mobility was associated with increased movement time and decreased displacement of CoP in poststroke patients. Trunk rolling performance has potential in assessment of stroke patients.