Effect and feasibility of the combination of branched chain amino acid and exercise therapy on muscle mass and echo intensity of muscle in orthopedic patients in a convalescent rehabilitation hospital: A crossover trial.

Background and Aims: This study examined the feasibility of nutritional support combined with exercise intervention for restoring muscle and physical functions in convalescent orthopedic patients. Methods: We used a crossover design in which nutritional support combined with exercise intervention was administered daily during the early (1 month) and late (1 month) cycles with a 1-week washout period. The exercise intervention was performed twice daily for 2 months in the early and late groups. The exercise intervention consisted of one set of muscle strength, stretching, and physical activity exercises for 20 min each. Nutritional interventions were administered immediately after the exercise. A 3.4 g of branched-chain amino acid supplements (BCAAs) or 1.2 g of starch was ingested. We measured the skeletal muscle mass and isometric muscle strength of the limbs and performed balance tests. After the crossover, the BCAA and Placebo groups were compared. Results: The ratio of improvement in the echo intensity of the rectus femoris (RF) was significantly higher in the BCAA group. A comparison of the order of nutritional intervention showed a significant effect on the RF echo intensity in both groups only when BCAAs were administered. Conclusion: This study's results suggest that the proposed combined intervention improves muscle quality and mass in convalescent orthopedic patients.

The Effects of Timing of a Leucine-Enriched Amino Acid Supplement on Body Composition and Physical Function in Stroke Patients: A Randomized Controlled Trial.

The combination of exercise and nutritional intervention is widely used for stroke patients, as well as frail or sarcopenic older persons. As previously shown, supplemental branched chain amino acids (BCAAs) or protein to gain muscle mass has usually been given just after exercise. This study investigated the effect of the timing of supplemental BCAAs with exercise intervention on physical function in stroke patients. The participants were randomly assigned to two groups based on the timing of supplementation: breakfast (n = 23) and post-exercise (n = 23). The supplement in the breakfast group was provided at 08:00 with breakfast, and in the post-exercise group it was provided just after the exercise session in the afternoon at 14:00-18:00. In both groups, the exercise intervention was performed with two sessions a day for two months. The main effects were observed in body fat mass (p = 0.02, confidence interval (CI): 13.2-17.7), leg press strength (p = 0.04, CI: 94.5-124.5), and Berg balance scale (p = 0.03, CI: 41.6-52.6), but no interaction with intake timing was observed. Although the effect of the timing of supplementation on skeletal muscle mass was similar in both groups, BCAA intake with breakfast was effective for improving physical performance and decreasing body fat mass. The results suggest that a combination of BCAA intake with breakfast and an exercise program was effective for promoting rehabilitation of post-stroke patients.

Strain-rate dependence of viscous properties of the plantar soft tissue identified by a spherical indentation test.

The mechanical properties of the plantar soft tissue are known to vary in diabetic patients, indicating that parameter identification of the mechanical properties of the foot tissue using an indentation test is clinically important for possible early diagnosis and interventions of diabetic foot. However, accurate mechanical characterization of the viscous properties of the plantar soft tissue has been difficult, as measured force-relaxation curves of the same soft tissue differ depending on how the material is loaded. In the present study, we attempted to clarify how the indentation rate of the plantar soft tissue affects the measured force-relaxation curves, which is necessary in order to identify the viscoelastic properties. The force-relaxation curves of the heel pads were obtained from the indentation experiment in vivo at indentation rates of 15, 25, 50, 75, and 100 mm/s. The curves were fit to an analytical contact model of spherical indentation incorporating a five-element Maxwell model. The results of the present study demonstrated that, although experimentally obtained force-relaxation curves were actually variable depending on the indentation rate, similar viscous parameters could be identified for the same heel if the effects of (1) the underestimation of the peak force due to the energy dissipation occurring during indentation and (2) the deceleration of the indenter at the target position were incorporated in the parameter identification process. The indentation-rate-independent viscous properties could therefore be estimated using the proposed method.

Effect of exercise therapy combined with branched-chain amino acid supplementation on muscle strength in elderly women after total hip arthroplasty: a randomized controlled trial.

BACKGROUND AND OBJECTIVES: Many patients develop a prolonged decrease of muscle strength after total hip arthroplasty (THA) despite their reconstructed hip joint. Physical exercise combined with branched-chain amino acid (BCAA) supplementation has been reported to improve muscle strength in elderly persons with sarcopenia. However, the effect of BCAA supplementation in patients after THA is unknown. This study examined the effects of BCAA supplementation combined with exercise therapy on the improvement of physical function in elderly patients after THA. METHODS AND STUDY DESIGN: The subjects were 31 elderly women who underwent THA. The participants were randomly assigned to two groups: BCAA (n=18) and control (n=13). The combined therapy was carried out for one month after THA. For the exercise intervention, a 3-set physical exercise program was conducted. For the nutritional intervention, the participants consumed 3.4 g of BCAA supplement or 1.2 g of starch immediately after the exercise intervention. RESULTS: BCAA supplementation combined with muscle strengthening exercises had a significant effect on knee extension strength of the contralateral side and on upper arm cross-sectional area. The improvement ratio of knee extension strength before and after intervention on the operated side was also significantly higher in the BCAA group. CONCLUSIONS: BCAA supplementation is effective for patients to improve the strength of some muscles when combined with physical exercises, but hip abductor muscle strength of the operated leg did not improve. A future study is needed to determine the efficacy of this combined therapy for hip abductor muscle strength.

Effect of ankle-foot orthosis on level walking in healthy subjects.

An ankle-foot orthosis is often prescribed in the rehabilitation of patients with neurological motor disorders such as hemiparesis. However, walking with a unilateral ankle-foot orthosis may not be effectively achieved just by trying to reproduce normal intact walking with a symmetrical gait pattern. Understanding skills to facilitate walking gait with a unilateral ankle-foot orthosis has implications for better rehabilitative interventions to help restore walking ability in patients with stroke. We, therefore, analyzed the kinematics and ground reaction forces of walking with and without an ankle-foot orthosis in healthy subjects to infer the possible skills to facilitate walking gait with a unilateral ankle-foot orthosis. Adult male participants were asked to walk with and without an ankle-foot orthosis across two force platforms set in a wooden walkway, and body kinematics and ground reaction force profiles in the sagittal plane were simultaneously recorded. We found that the forward tilting angle of the trunk at the time of toe-off of the leg with the ankle-foot orthosis was significantly larger than that of the leg without the ankle-foot orthosis, to adaptively compensate for the loss of ankle joint mobility due to the unilateral ankle-foot orthosis. Furthermore, the peak vertical ground reaction force at heel-contact was significantly larger in the leg without the ankle-foot orthosis than in the leg with the ankle-foot orthosis owing to the fact that the stance phase duration of the leg with the ankle-foot orthosis was relatively shorter. Such information may potentially be applied to facilitate walking training in stroke patients wearing a unilateral ankle-foot orthosis.

Motion-plane dependency of the range of dart throw motion and the effects of tendon action due to finger extrinsic muscles during the motion.

[Purpose] To clarify the motion-plane dependency of the range of dart throw motion and the effects of tendon action due to long finger flexors and extensors during the motion. [Subjects and Methods] Forty healthy subjects attended the experiment, and the active range of wrist motion in seven motion planes was measured with an originally designed apparatus. [Results] The reliability of the measurement was acceptable. The range of dart throw motion depended on the motion planes, with a maximum at around the motion plane of 45° from the sagittal plane (45° of pronation). The tendon action of long finger muscles was shown in dart throw motion except in 45° of pronation. [Conclusion] Motion-plane dependency of the range of dart throw motion exists in healthy subjects. The absence of tendon action due to finger extrinsic muscles in dart throw motion at 45° might be one of the causes of the advantage of dart throw motion.

Weight-shift ability significantly correlates with walking velocity in post-acute stroke patients.

The ability to shift weight toward the paretic leg has been considered an essential ability to restore independent walking for post-acute stroke patients. However, few data are available regarding the relationship between the weight-shift ability and gait performance. No clear mechanism has been provided as to why and how the weight-shift ability improves walking performance in stroke patients. We therefore investigated changes in the weight-shift ability and kinematic and kinetic parameters of walking gait in post-stroke patients during rehabilitation. Eight male inpatients undergoing rehabilitation for moderate hemiplegia participated in this study. Measurements were taken every 4 weeks from when the participants were able to walk at least 10 m until they were discharged from the hospital. Our results demonstrated a significant overall correlation between the weight-shift ability and walking velocity, indicating that the improvement in the weight-shift ability toward the paretic leg by lateral tilting of the thorax is fundamentally important to improve walking velocity. We also found that the upward impulse and vertical ground reaction force exerted by the paretic leg were significantly correlated with the walking velocity to cope with the downward impulse due to gravity and to allow sufficient time to swing the non-paretic leg forward during walking. Therefore, improvement in the weight-shift ability is crucial for restoration of walking velocity. We believe that weight-shift training for the paretic leg while instructing the patients to laterally tilt the thorax should be advocated as an effective protocol during rehabilitation of post-acute stroke inpatients.

Accuracy evaluation of a method to partition ground reaction force and center of pressure in cane-assisted gait using an instrumented cane with a triaxial force sensor.

Clarifying the biomechanics of cane-assisted gait in elderly individuals and patients with gait disorders is important for developing better therapeutic interventions in the fields of rehabilitation and orthopedics. However, if the foot and the cane in the ipsilateral hand are placed on the same force plate simultaneously, the force plate cannot separate the forces as it records the sum of the forces. To overcome this indeterminacy problem of the ground reaction force (GRF) and the center of pressure (COP) in cane-assisted gait analysis, a method to partition the GRF and COP using an instrumented cane with a force transducer has been proposed. However, the accuracy and precision of the estimated GRF and COP has not been evaluated previously. We therefore reestablished a framework to partition the foot and cane forces during walking using an instrumented cane with a triaxial force sensor and evaluated the accuracy and precision of the method using a force plate array. Cane-assisted gait of healthy adults and hemiplegic patients were measured. Mean accuracy and precision associated with the GRF and COP measurements were approximately 0.4±1.4N and 0.2±2.7mm, respectively, indicating that the separations of the GRF and COP were sufficiently accurate for kinetic gait analysis. Although some methodological limitations certainly apply, this system will serve as a useful tool for improved therapeutic interventions.