Effects of different types of exercise on muscle activity and balance control

Efficacy and safety of hydrokinesitherapy in patients with dystrophinopathy

Duchenne muscular dystrophy (DMD) is one of the most common forms of hereditary muscular dystrophies in childhood and is characterized by steady progression and early disability. It is known that physical therapy can slow down the rate of progression of the disease. According to global recommendations, pool exercises, along with stretching, are preferable for children with DMD, as these types of activities have a balanced effect on skeletal muscles and allow simultaneous breathing exercises. The present study aimed to evaluate the effectiveness of regular pool exercises in patients with Duchenne muscular dystrophy who are capable of independent movement during 4 months of training. 28 patients with genetically confirmed Duchenne muscular dystrophy, who were aged 6.9 ± 0.2 years, were examined. A 6-min distance walking test and timed tests, namely, rising from the floor, 10-meter running, and stair climbing and descending, muscle strength of the upper and lower extremities were assessed on the baseline and during dynamic observation at 2 and 4 months. Hydrorehabilitation course lasted 4 months and was divided into two stages: preparatory and training (depend on individual functional heart reserve (IFHR)). Set of exercises included pool dynamic aerobic exercises. Quantitative muscle MRI of the pelvic girdle and thigh was performed six times: before training (further BT) and after training (further AT) during all course. According to the results of the study, a statistically significant improvement was identified in a 6-min walking test, with 462.7 ± 6.2 m on the baseline and 492.0 ± 6.4 m after 4 months (p < 0.001). The results from the timed functional tests were as follows: rising from the floor test, 4.5 ± 0.3 s on the baseline and 3.8 ± 0.2 s after 4 months (p < 0.001); 10 meter distance running test, 4.9 ± 0.1 s on the baseline and 4.3 ± 0.1 s after 4 months (p < 0.001); 4-stair climbing test, 3.7 ± 0.2 s on the baseline and 3.2 ± 0.2 s after 4 months (p < 0.001); and 4-stair descent test, 3.9 ± 0.1 s on the baseline and 3.2 ± 0.1 s after 4 months (p < 0.001). Skeletal muscle quantitative MRI was performed in the pelvis and the thighs in order to assess the impact of the procedures on the muscle structure. Muscle water T2, a biomarker of disease activity, did not show any change during the training period, suggesting the absence of deleterious effects and negative impact on disease activity. Thus, a set of dynamic aerobic exercises in water can be regarded as effective and safe for patients with DMD.

Inter-rater and intra-rater reliability of isotonic exercise monitoring device for measuring active knee extension

Background

The goal of this study was to assess the reliability of electromyography and range of motion measurements obtained using a knee exercise monitoring system. This device was developed to collect data on knee exercise activities.

Methods

Twenty healthy individuals performed isotonic quadriceps exercises in this study. The vastus medialis surface electromyography (sEMG) and range of motion (ROM) of the knee were recorded during the exercise using the isotonic knee exercise monitoring device, the Mobi6-6b, and a video camera system. Each subject underwent a second measuring session at least 24 h after the first session. To determine reliability, the intraclass correlation coefficients (ICCs) and standard error of measurement (SEM) at the 95% confidence interval were calculated, and a Bland-Altman analysis was performed.

Results

For inter-rater reliability, the ICCs of the mean absolute value (MAV) and root mean square (RMS) of sEMG were 0.73 (0.49, 0.86) and 0.79 (0.61, 0.89), respectively. ROM had an ICC of 0.93 (0.02, 0.98). The intra-rater reliability of the MAV of the sEMG was 0.89 (0.71, 0.96) and the intra-rater reliability of RMS of the sEMG was 0.88 (0.70, 0.95). The ROM between days had an intra-rater reliability of 0.82 (0.54, 0.93). The Bland-Altman analysis demonstrated no systematic bias in the MAV and RMS of sEMG, but revealed a small, systematic bias in ROM (-0.8311 degrees).

Conclusion

For sEMG and range of motion measures, the isotonic knee exercise monitoring equipment revealed moderate to excellent inter- and intra-rater agreement. However, the confidence interval of ROM inter-rater reliability was quite large, indicating a small agreement bias; hence, the isotonic knee exercise monitor may not be suitable for measuring ROM. This isotonic knee exercise monitor could detect and collect information on a patient's exercise activity for the benefit of healthcare providers.

Effect of Three-Month Weight Training Program on Resting Heart Rate and Blood Pressure in Healthy Young Adult Males

Background A planned and structured physical activity is the cornerstone of improving and sustaining body fitness. The underlying reason for exercise is personal interest, maintaining good health, or improving endurance for sports. Furthermore, exercise may be either isotonic or isometric. In weight training, different types of weight are being used and are lifted against gravity, and this type of exercise is of isotonic type. Objective The objective of this study was to observe the changes in heart rate (HR) and blood pressure (BP) after a three-month weight training intervention in healthy young adult males and to compare them with age-matched healthy control. Materials and methods We initially recruited a total of 25 healthy male volunteers for the study and 25 age-matched participants in the control group. Research participants were screened for any existing diseases and suitability for participation by the Physical Activity Readiness Questionnaire. We lost one participant from the study group and three participants from the control group in the follow-up. A structured weight training program (five days a week for three months) was applied for the study group with direct instruction and supervision in a controlled environment. A single expert clinician measured baseline and post-program (after three months) HR and BP (measured after 15 minutes, 30 minutes, and 24 hours of rest after exercise) to reduce any possible inter-observer variation. For comparing the pre-exercise and post-exercise parameters, we considered the post-exercise measurement, which was done after 24 hours of exercise. Mann-Whitney U test, Wilcoxon signed-rank test, and Friedman test compared the parameters. Result A total of 24 males with a median age of 19 years (Q1-Q3: 18-20) participated as the study group and 22 males with the same median age were the control group. At the end of the three-month weight training exercise program, there was no significant change in the HR (median 82 versus 81 bpm, p = 0.27) in the study group. The systolic BP was increased (median 116 versus 126 mmHg, p <0.0001) after three months of the weight training program. In addition, pulse pressure and mean arterial BP was also increased. However, diastolic (median 76 versus 80 mmHg, p = 0.11) BP was not significantly increased. There was no change in HR, systolic and diastolic BP in the control group. Conclusion A structured weight training program (used in this study) for three months may sustain an increase in systolic BP at rest in young adult males while diastolic BP remains the same. The HR remains unchanged before and after the exercise program. Hence, those enrolling in such an exercise program should be monitored frequently for changes in BP over time for any timely intervention appropriate for the candidate. However, being a small-scale study, the result of this study would be validated by further observing the underlying causes of the increment of systolic blood pressure.

The limits of stability and muscle activity in middle-aged adults during static and dynamic stance

Balance control plays an important role in maintaining daily activity. However, studies on postural control among middle-aged adults are scarce. This study aims (i) to examine directional control (DCL) and electromyography activity (EMG) for different stability levels, and (ii) to determine left-right asymmetry for DCL and muscle activity among sedentary middle-aged adults. Twenty healthy, middle-aged adults (10 males, 10 females; age=50.0±7.5yrs; body height: 1.61±0.10m; body mass: 70.0±14.5kg) participated in the study. EMG for left and right side of rectus femoris (RF), biceps femoris (BF), and medial gastrocnemius (MG) were recorded. Two-way repeated measures analysis of variance was used to assess the effect of dynamic level on DCL and EMG, whereas independent sample t-test was conducted to analyse the asymmetries of DCL and EMG for the left and right leg. When the dynamic tilt surface increased, DCL scores significantly decreased (except forward, forward-rightward, and backward-leftward direction) and only RF muscle indicated significant differences. Left-right asymmetry was found in BF and MG muscles. No significant gender difference was observed in DCL and EMG. These data demonstrated that increased dynamic tilt surface may increase the displacement of center of pressure of certain directions, and stimulate RF activity in dynamic stance among sedentary middle-aged adults. Further studies should be conducted to examine the dynamic stance and muscle activity of the lower limb in age-matched patient groups with balance abnormalities.

The Impact of Walking Exercises and Resistance Training upon the Walking Distance in Patients with Chronic Lower Limb Ischaemia

Objective. The objective of this paper is to compare the impact of supervised walking and resistance training upon the walking distance in PAD patients. Materials and Methods. The examination involved 50 PAD patients at the 2nd stage of the disease according to Fontaine's scale. The participants were randomly allocated to two groups: one exercising on the treadmill (n = 24) and one performing resistance exercises of lower limbs (n = 26). Results. The 12-week program of supervised rehabilitation led to a significant increase in the intermittent claudication distance measured both on the treadmill and during the 6-minute walking test. The group training on the treadmill showed a statistically significant increase of the initial claudication distance (ICD) and the absolute claudication distance (ACD) measured on the treadmill, as well as of ICD and the total walking distance (TWD) measured during the 6-minute walking test. Within the group performing resistance exercises, a statistically significant improvement was observed in the case of parameters measured on the treadmill: ICD and ACD. Conclusions. The supervised rehabilitation program, in the form of both walking and resistance exercises, contributes to the increase in the intermittent claudication distance. The results obtained in both groups were similar.

Weight loss may be a better approach for managing musculoskeletal conditions than increasing muscle mass and strength

To prevent or remedy musculoskeletal conditions, the relationship between obesity and the characteristics of muscle mass and strength need to be clarified. [Subjects and Methods] A total of 259 Japanese males aged 30–64 years were classified into 4 groups according to the Japanese obesity criteria. Body composition was evaluated, and handgrip strength and knee extensor strength were measured for the upper and lower extremities, respectively. Physical performance was evaluated with a jump test. [Results] Obesity was positively correlated with skeletal muscle mass index, percentage of whole-body fat, and leg muscle strength and negatively correlated with the percentage of muscle mass index, body weight-normalized handgrip strength, and knee extensor strength, and the jump test results. [Conclusion] Weight loss may be a better approach than increasing muscle mass and strength to improve musculoskeletal conditions in obese adult males.