The Effects of Sling Exercise Using Vibration on Trunk Muscle Activities of Healthy Adults

[Purpose] This study compared the effects of sling exercises with and without vibration on the muscular activity of the internal oblique (IO), rectus abdominis (RA), multifidus (MF), and erector spinae (ES) muscles of healthy adults. [Methods] Eleven healthy university students (11 men) with a mean age of 22.8 years were enrolled in this study. Subjects performed supine and prone bridge exercises with the knees flexed using a sling suspension system with and without vibration. The amplitudes of the EMG activities of selected trunk muscles (internal oblique, rectus abdominis, erector spinae, multifidus) were recorded. Two types of exercise conditions were executed in a random sequence for 5 seconds each. The signals detected from the middle 3 seconds (after discarding the signals of the first and the last one seconds) were used in the analysis. A 3-minute break was given after each exercise to minimize muscle fatigue. [Results] During the supine bridge exercise with vibration, the activities of the IO, RA, MF, and ES muscles were significantly higher than those of the supine bridge exercise without vibration. Additionally, during the prone bridge exercise with vibration, the activities of the IO, RA, MF, and ES were significantly higher than those of the prone bridge exercise without vibration. [Conclusion] Sling exercises with vibration improved the trunk muscle activities of healthy adults compared to the sling exercises without vibration. The information presented here is important for clinicians who use lumbar stabilization exercises as an evaluation tool or a rehabilitation exercise.Key words: Sling exercise, Vibration, Trunk muscle     

The Effects of Visual Field Conditions on Electromyography of the Lower Extremities during Reaching Tasks in Healthy Adults

[Purpose] The purpose of this study was to identify the effects of visual field condition on electromyography of the lower extremities during arm reaching in healthy adults, and to compare differences in electromyography of the lower extremities between young and old adults according to visual fields condition. [Subjects and Methods] Twenty-nine young persons in their 20s and 19 elderly persons in their 60s, a total of 48 persons, participated in this study. Prior to participation in the study, each subject signed an informed consent form to comply with ethics guidelines dictated by the ethics committee for research at Silla University, Korea. We collected the muscle activation data for both of tibialis anterior and gastrocnemius muscle during reaching by subjects using electromyography. Data analysis with SPSS for Window Version 20.0 was performed using repeated one-way analysis of variance according to visual fields and age. [Results] There were no significantly differences between subjects in their 20s and 60s to visual field conditions except for left tibialis anterior muscle activation during left-side reaching. Left tibialis anterior muscle activation in subjects in their 60s was higher than in subjects in their 20s during left-side reaching. [Conclusion] We determined that tibialis anterior muscle activation in subjects in their 60s was higher than in subjects in their 20s. We suggest that visual field conditions are the important factor for physical therapy interventions to improve balance and priority of intervention .Key words: Visual field condition, Reaching task, Lower extremities muscle activity     

Effect of Virtual Reality Exercise Using the Nintendo Wii Fit on Muscle Activities of the Trunk and Lower Extremities of Normal Adults

[Purpose] The present study aimed to determine the effect of virtual reality exercise using the Nintendo Wii Fit on the muscle activities of the trunk and lower extremities of normal adults. [Subjects] The subjects of the study were 24 normal adults who were divided into a virtual reality exercise group (VREG, n=12) and a stable surface exercise group (SEG, n=12). [Methods] The exercises of the VREG using the Nintendo Wii Fit and the SEG using a stable surface were conducted three times a week for six weeks. Electromyography was used to measure the muscle activities of the tibialis anterior (TA), medial gastrocnemius (MG), erector spinae (ES), and rectus abdominal (RA) muscles. [Results] VREG showed significant within group differences in TA and MG muscle activities, while the SEG showed a significant difference in the muscle activity of the MG. [Conclusion] Virtual reality exercise using the Nintendo Wii Fit was an effective intervention for the muscle activities of the TA and MG of normal adults.Key words: Virtual reality exercise, Stable surface exercise, Muscle activity     

The Influence of Dual Pressure Biofeedback Units on Pelvic Rotation and Abdominal Muscle Activity during the Active Straight Leg Raise in Women with Chronic Lower Back Pain

[Purpose] This study was performed to assess the influence of applying dual pressure biofeedback units (DPBUs) on the angle of pelvic rotation and abdominal muscle activity during the active straight leg raise (ASLR). [Subjects] Seventeen patients with low-back pain (LBP) participated in this study. [Methods] The subjects were asked to perform an active straight leg raise (ASLR) without a PBU, with a single PBU, and with DPBUs. The angles of pelvic rotation were measured using a three-dimensional motion-analysis system, and the muscle activity of the bilateral internal oblique abdominis (IO), external oblique abdominis (EO), and rectus abdominis (RA) was recorded using surface electromyography (EMG). One-way repeated-measures ANOVA was performed to determine the rotation angles and muscle activity under the three conditions. [Results] The EMG activity of the ipsilateral IO, contralateral EO, and bilateral RA was greater and pelvic rotation was lower with the DPBUs than with no PBU or a single PBU. [Conclusion] The results of this study suggest that applying DPBUs during ASLR is effective in decreasing unwanted pelvic rotation and increasing abdominal muscle activity in women with chronic low back pain.Key words: Active straight leg raise, Pelvic rotation, Pressure biofeedback unit     

Assessment of Effective Ankle Joint Positioning in Strength Training for Intrinsic Foot Flexor Muscles: A Comparison of Intrinsic Foot Flexor Muscle Activity in a Position Intermediate to Plantar and Dorsiflexion with that in Maximum Plantar Flexion Using Needle Electromyography

[Purpose] The effectiveness of intrinsic foot flexor strength training performed in the plantar flexion position was examined using needle electromyography. [Subjects] The subjects of this study were 18 healthy men. [Methods] We used needle electromyography to measure the muscle activities of the flexor hallucis brevis (FHB), and the flexor digitorum brevis (FDB) in maximum plantar and an intermediate position. [Results] Significant increases in muscle activities were observed for both FHB and FDB, and the rates of increase from the intermediate position to the plantar flexion position were 43% for FHB and 46% for FDB. [Conclusion] This study demonstrated that it is possible to evaluate intrinsic foot flexors, in addition to the numerous reports on treatment methods focusing on extrinsic foot flexors. Furthermore, the results suggest that toe flexion exercises performed during plantar flexion of the ankle joint are an effective method for intrinsic foot flexor strength training.Key words: Intrinsic foot flexor muscles, Needle electromyography, Muscle activity     

The Effects on Muscle Activation of Flatfoot during Gait According to the Velocity on an Ascending Slope

[Purpose] This study determined the difference between flatfeet and normal feet in humans on an ascending slope using electromyography (EMG). [Subjects] This study was conducted on 30 adults having normal feet (n=15) and flatfeet (n=15), all of whom were 21 to 30 years old. [Methods] A treadmill (AC5000M, SCIFIT,) was used to analyze kinematic features during gait. These features were analyzed at slow, normal, and fast gait velocities on an ascending slope. A surface electromyogram (TeleMyo 2400T, Noraxon Co., USA) was used to measure muscle activity changes. [Results] The activities of most muscles in the subjects with flatfeet were significantly different from the muscle activities in the subjects with normal feet at different gait velocities on an ascending slope. There were significant differences in the vastus medialis and abductor hallucis muscles. [Conclusion] Because muscle activation of the vastus medialis in relation to stability of the lower extremity has a tendency to increase with an increase in gait velocity on an ascending slope, we hypothesized that higher impact transfer to the knee joints occurs in subjects with flatfeet due to the lack of a medial longitudinal arch and that the abductor halluces muscles, which provide dynamic stability to the medial longitudinal arches, do not activate well when they are needed in subjects with flatfeet.Key words: Flat foot, Electromyography, Ascending slope     

The Effect of an Inclined Ankle on the Activation of the Abductor Hallucis Muscle during Short Foot Exercise

[Purpose] The purpose of this study was to identify the effects of an inclined ankle on the activation of the abductor hallucis muscle during short foot exercises. [Subjects] We recruited 14 healthy volunteers who were free of pain, and did not suffer from arthritis or osteomuscular problems related to the foot or ankle. [Methods] The subjects performed short foot exercises and short inclined foot exercises with 30° passive ankle dorsiflexion. [Results] The exercise with an inclined foot showed a significantly larger activation of the abductor hallucis than that shown during the neutral short foot exercises. [Conclusion] These results suggest that passive ankle dorsiflexion during short foot exercise for strengthening the abductor hallucis is a more effective clinical treatment exercise.Key words: Abductor hallucis, Inclined ankle, Short foot exercise     

Comparison of Muscle Activities Using a Pressure Biofeedback Unit during Abdominal Muscle Training Performed by Normal Adults in the Standing and Supine Positions

[Purpose] The purpose of this study was to assess the effects of draw-in exercise on abdominal muscle activity in the standing and supine positions. [Methods] Twenty healthy women participated in this study. The subjects were required to complete two draw-in exercises (standing and supine positions) using a biofeedback pressure unit. The root mean square (RMS) values of the EMG data were expressed as a percentage of the resting contraction. The data were analyzed using the independent t-test. [Results] According to the changes in the activities of the abdominal muscles, the draw-in exercise in the standing position produced the most significant increase in the activities of the rectus abdominis, the transverse abdominis, the internal oblique, and the external oblique muscles. [Conclusion] The activities of the trunk stability muscles (rectus abdominis, transverse abdominis, internal oblique, and external oblique) increased more in the standing than in the supine position, enabling the subjects to overcome gravity. Therefore, to strengthen the activation of the abdominal muscles, a standing position seems to be more effective than a supine position for draw-in exercises.Key words: Abdominal muscle activity, Positions, Pressure biofeedback unit     

Effect of the Foot Placements on the Latissmus Dorsi and Low Back Muscle Activities during Pull-down Exercise

[Purpose] The purpose of this study was to examine the effects of foot placement on the latissmus dorsi and low back muscles activities during pull-down exercise. [Subjects] For this study, we recruited 10 male volunteers. [Methods] The subjects performed pull-down exercises with 4 foot placement conditions. The activities of the latissmus dorsi and L4 paraspinal muscles were measured. [Results] The activities of the latissmus dorsi muscles significantly increased in the order of conditions 1 and 2 < condition 4 < condition 3. The activities of the L4 paraspinal muscles were significantly different, with the activities of conditions 1 and 2 being greater than those of conditions 3 and 4. [Conclusion] We suggest that the selection of foot placement is an important factor for the effective strengthening of the latissmus dorsi.Key words: Foot placement, Latissmus dorsi, Pull-down exercise     

The Effect of Trunk Stabilization Exercise Using an Unstable Surface on the Abdominal Muscle Structure and Balance of Stroke Patients

[Purpose] This study investigated the effect of unstable surface trunk stabilization exercise on the abdominal muscle structure and balance of stroke patients. [Subjects] The subjects were divided into two groups: an unstable surface trunk stabilization exercise group (n=13), and a stable surface trunk stabilization exercise group (n=11). [Methods] Both groups performed trunk stabilization exercise for 30 minutes, 3 days per week for 6 weeks. Abdominal muscle thickness and the Berg Balance Scale (BBS) were measured at the baseline and after 6 weeks. [Results] There was a significant improvement in the internal oblique muscle thickness, transversus abdominis thickness and balance ability of the unstable surface trunk stabilization exercise group. [Conclusion] The unstable surface trunk stabilization exercise improved the internal oblique and transversus abdominis muscles and balance ability. These results suggest that unstable surface trunk exercise is useful in the rehabilitation stroke patients.Key words: Unstable surface, Trunk stabilization exercise, Muscle thickness     

Effect of the Mandibular Orthopedic Repositioning Appliance on Trunk and Upper Limb Muscle Activation during Maximum Isometric Contraction

[Purpose] The purpose of this study was to measure the muscle activities of the trunk muscles and upper limb muscles during maximum isometric contraction when temporomandibular joint alignment was achieved with a mandibular orthopedic repositioning appliance in order provide basic data on the effects of mandibular orthopedic repositioning appliance on the entire body. [Subjects] The present study was conducted with healthy Korean adults in their 20s (males=10, females=10). [Methods] An 8 channel surface electromyography system was used to measure the muscle activities of the upper limb muscles and neck muscles of the subjects during maximum isometric contraction with and without use of a mandibular orthopedic repositioning appliance. [Results] The maximum isometric contractions of the trunk and upper limb muscles when mandibular orthopedic repositioning appliance were used were compared with those when no mandibular orthopedic repositioning appliance was used. The results showed that the sternocleidomastoid muscle, cervical and lumbar erector spinae, upper trapezius, biceps, triceps, rectus abdominis and internal oblique and external oblique muscles all showed significant increases in maximum isometric contractions with a mandibular orthopedic repositioning appliance. [Conclusion] The use of a mandibular orthopedic repositioning appliance is considered to be a method for normal adults to improve the stability of the entire body with the improvement of the stability of the TMJ. The proximal improvement in stability improves of the proximal thereby improving not only muscle strength with increased muscle activation but also stability during exercises.Key words: Electromyography, Maximum isometric contraction, MORA     

The Correlation between the Muscle Activity and Joint Angle of the Lower Extremity According to the Changes in Stance Width during a Lifting Task

[Purpose] This study examined the correlation between the muscle activities and joint angle of the hip and knee according to the changes in stance width during a lifting task. [Subjects and Methods] The subjects of this study were 15 healthy students. A three-dimensional motion analyzer (SMART-E, BTS, Italy) was used to measure the joint angles of hip and knee during lifting. An 8-channel electromyograph (8-EMG) (Pocket EMG, BTS, Italy) was used to measure muscle activities of the erector spinae, gluteus maximus, rectus femoris, and tibialis anterior during lifting. The collected data were analyzed using the Pearson-test and SPSS 18.0. [Result] The muscle activity of the tibialis anterior was significantly decreased by increasing the stance width (r= −0.285). Muscle activity of the erector spinae was significantly decreased by increasing the knee angle (r= −0.444). The muscle activity of the gluteus maximus was significantly increased by increasing the muscle activity of the tibialis anterior (r= 0.295). [Conclusion] Efficient lifting is possible when stance width and knee flexion are increased, which results in reduced muscle activity of the tibialis anterior and the erector spinae. Lifting is facilitated when the muscle activities of the gluteus maximus and tibialis anterior are correlated.Key words: Muscle activity, Joint angle, Lifting     

Changes in the Activities of the Trunk Muscles in Different Kinds of Bridging Exercises

[Purpose] The purpose of this study was to examine the effects of different types of bridging exercises on the activities of the trunk muscles. [Methods] Twenty-four students participated in this experiment. The activities of the internal oblique (IO), external oblique (EO), rectus abdominis (RA), and erector spinae (ES) muscles were measured in four different bridging exercises. [Results] There were significant differences in the IO, EO, RA, and ES among the four kinds of bridging exercise. The activities of IO, EO and RA were the highest in prone bridging (exercise 4), followed by unilateral bridging (exercise 3), and supine bridging on balance pads (exercise 2). In conventional bridging (exercise 1), the activities of IO, EO, and RA were the lowest. The activity of ES was the highest in exercise 3 followed by exercises 2 and 1. The activity of ES was the lowest than in exercise 1. [Conclusions] Bridging exercise in the prone position may be a more effective method of enhancing trunk muscle activities exercises in other positions.Key words: Bridge exercise, Muscle activity, EMG     

Effect of the Shoulder Flexion Angle in the Sagittal Plane on the Muscle Activities of the Upper Extremities when Performing Push-up plus Exercises on an Unstable Surface

[Purpose] The purpose of this study was to investigate the effect of the shoulder flexionangle on the muscle activities of the upper extremities when performing the push-up plusexercise (PUPE) on an unstable surface with the forearm in the external rotation position.[Subjects] The subjects were conducted on 15 normal male adults. [Methods] A sling devicewas used for the unstable surface, and PUPE was performed with the forearm in the externalrotation position. The shoulder flexion angles measured in the sagittal plane were 110°,90°, and 70°. Electromyography was used for a comparitive analysis of the muscleactivities of the serratus anterior (SA), the pectoralis major (PM), and the uppertrapezius (UT). [Results] In the intra-group comparison, the muscle activity of SA wasstatistically the highest when the shoulder-flexion angle was 110°. [Conclusion]performing PUPE on an unstable surface, the muscle activity of the SA is activated themost when the shoulder flexion angle is 110° and the forearm is in the external rotationposition.     

Effect of Exercise Speed and Isokinetic Feedback on the Middle and Lower Serratus Anterior Muscles during Push-up Exercises

[Purpose] This study assessed the use of different exercise speeds and isokinetic feedback on the middle and lower serratus anterior muscles during push-up exercises. [Subjects] Ten male workers voluntarily consented to participate in the study. [Methods] The subjects performed push-up exercises under three conditions. Surface electrodes were placed on the dominant right side of the middle and lower serratus anterior muscles. [Results] The middle and lower SA muscle activities under condition 2 were significantly decreased when compared with those under conditions 1 and 3. The middle SA activity under condition 3 was significantly increased when compared with that under condition 1. [Conclusion] This study suggests that proper selection of push-up exercise speed may be necessary for selective strengthening of the SA and that isokinetic feedback information obtained using an accelerator can help in selective strengthening of the middle SA.Key words: Accelerator, Isokinetic feedback, Middle SA     

The Influence of an Unstable Surface on Trunk and Lower Extremity Muscle Activities during Variable Bridging Exercises

[Purpose] The aim of this study was to investigate the influence of an unstable surface on trunk and lower extremity muscle activities during various types of bridging exercises. [Subjects] Thirty healthy female adults voluntarily participated in this study. [Methods] All subjects were asked to perform 3 different bridging exercises (bridging exercise, single leg lift bridging exercise, single leg cross bridging exercise) with and without an unstable surface. The trunk and lower extremity muscle activities were measured by using surface electromyography during bridging exercise. [Results] During the bridging exercise (BE), single leg lift bridging exercise (LBE), and single leg cross bridging exercise (CBE), the muscle activities of the external oblique muscle (EO), erector spinae (ES), and biceps femoris (BF) were significantly higher on an unstable surface than on a stable surface. The muscle activities of the EO on both sides, contralateral BF, and ipsilateral ES were significantly higher during LBE than during BE and CBE. [Conclusion] Use of an unstable surface increases muscle activity of the trunk and lower extremities, and single leg lift bridging exercise increases the muscle activity of the EO on both sides, ipsilateral ES, and contralateral BF.Key words: Bridging exercise, Electromyography, Unstable surface     

Effects of Sling Exercise Therapy on Trunk Muscle Activation and Balance in Chronic Hemiplegic Patients

Weakening of trunk muscles in stroke patients hinders functional ability, safety and balance. To confirm whether strengthening trunk muscles could facilitate rehabilitation of stroke patients, we investigated the effectiveness of sling exercise therapy (SET) using closed kinetic chain exercises to activate trunk muscles and improve balance in stroke patients. [Subjects and Methods] Twenty stroke patients with chronic hemiplegia were equally divided into 2 groups, a SET group and a control group that performed regular exercises on a mat with the assistance of a table. Patients in both groups exercised for 30 min, three times per week for 4 weeks. Trunk muscle activity was measured using surface electromyography, whereas balance was measured using the Berg Balance Scale, Frailty and Injuries Cooperative Studies of Intervention Technique, Timed Up & Go test, and BioRescue before and after the 4-week experimental period. [Results] Trunk muscle activity and balance before and after intervention in both groups were significantly different. However, no significant differences were observed between the 2 groups. [Conclusion] Although SET was not more effective than regular exercise, significant improvement was observed before and after SET. Therefore, SET can be considered effective in strengthening trunk muscles in stroke patients with chronic hemiplegia.Key words: Chronic stroke patients, Sling exercise therapy, Trunk muscles     

Effects of Bilateral Passive Range of Motion Exercise on the Function of Upper Extremities and Activities of Daily Living in Patients with Acute Stroke

[Purpose] To evaluate the effects of early passive range of motion exercise on the function of upper extremities and activities of daily living in patients with acute stroke. [Methods] A total of 37 patients with acute stroke in intensive care units, were assigned to the experimental group (n=19) and control group (n=18). The experimental group performed passive range of motion exercise twice a day, for 4 weeks, immediately after a pretest; the patients in the control group performed the range of motion exercise in the same manner for 2 weeks beginning 2 weeks after the pretest. The functions of upper extremities (edema, range of motion), manual function, and activities of daily living of both groups were measured before and at four weeks after the intervention. [Results] The experimental group showed a significant decrease in the edema of upper extremities compared with the control group. It also showed a significant increase in the range of motion, function of upper extremities, and the activities of daily living compared to the control group. [Conclusion] Passive range of motion exercise in the early stage can improve the function of upper extremities and activities of daily living in patients with acute stroke.Key words: Stroke, Range of motion, Upper extremity     

Effects of Inclined Treadmill Walking on Pelvic Anterior Tilt Angle, Hamstring Muscle Length,and Trunk Muscle Endurance of Seated Workers with Flat-back Syndrome

[Purpose] This study investigated the effects of inclined treadmill walking on pelvic anterior tilt angle, hamstring muscle length, and back muscle endurance of seated workers with flat-back syndrome. [Subjects] Eight seated workers with flat-back syndrome who complained of low-back pain in the L3–5 region participated in this study. [Methods] The subjects performed a walking exercise on a 30° inclined treadmill. We measured the pelvic anterior tilt angle, hamstring muscle length, and back muscle endurance before and after inclined treadmill walking. [Results] Anterior pelvic tilt angle and active knee extension angle significantly increased after inclined treadmill walking. Trunk extensor and flexor muscle endurance times were also significantly increased compared to the baseline. [Conclusion] Inclined treadmill walking may be an effective approach for the prevention or treatment of low-back pain in flat-back syndrome.Key words: Inclined treadmill walking, LBP, Seated workers     

Effect of the Push-up Plus (PUP) Exercise at Different Shoulder Rotation Angles on Shoulder Muscle Activities

[Purpose] Although the Push-Up Plus is a useful exercise method for shoulder stabilization, few studies have examined its effects at different angles of shoulder rotation. Therefore, the present study investigated the most effective exercise method for shoulder stabilization by analyzing muscle activities of the rotator cuff muscles at different angles of shoulder rotation. [Subjects] Fifteen healthy university students in their 20s were the subjects of this study. [Methods] Changes in muscle EMG related to shoulder stabilization were analyzed by performing the Push-Up Plus in shoulder positions of neutral, internal and external rotation. [Results] The highest muscle activity was found in external rotation, and in internal rotation the pectoralis major and levator scapula showed significantly lower activities than the other positions. [Conclusion] Selectively changing the rotation angle of the shoulder for different purposes of the shoulder exercise would be an effective exercise method.Key words: Shoulder, Stabilization, Rotation