Research using electromyography (EMG) requires an understanding of EMG methodology. Specific points to emphasize in EMG recording include: 1) the use of bipolar and monopolar recording, 2) analysis of raw EMG data, and 3) the relationship between muscle contraction and dynamic EMG data. EMG recording and analysis are essential to research in physical therapy.

The shoulder joint is called a complex, and consists of the sternoclavicular, acromioclavicular, scapulothoracic, and glenohumeral joints. It has a wide range of motion and contributes to the smoothness of upper limb function. The motor function of the upper limb is a complicated mechanism because the influence of the peripheral joints affects the shoulder joints, and it is difficult to understand. Electromyographic analysis of the shoulder joint function is useful for objectively presenting the effect of exercise therapy. Therefore, in this paper, we present the clinical applications of EMG data of shoulder joint function. Specifically, we focus on the following: 1) Understanding of muscle activity patterns according to the direction of movement of the shoulder joint and the elevation angle, taking into consideration the mechanism of the shoulder joint. 2) The shrug sign (shoulder shrinkage phenomenon) is a compensatory motion of shoulder joint disease cases. In addition to the activities of the elevator and retractor muscle groups of the shoulder girdle during this operation, the muscle activity of the supraspinatus muscle is also analyzed and discussed regarding its clinical applications. 3) Exercise posture (supine or lateral) promotes or suppresses treatment of the target muscles and re-education of muscle activity due to posture can be expected.

Motor imagery is beneficial for the improvement of motor function in physical therapy. In this study, the effect of motor imagery on the excitability of spinal motor neurons and motor accuracy was investigated. Motor imagery facilitated the excitability of spinal motor neurons, and the intensity of the imagined muscle contraction was not involved in the changes in spinal motor neurons’ excitability. Therefore, in clinical practice, motor imagery under only slight muscle contraction strength may be enough to improve motor function. In addition, the use of motor imagery during and after physical therapy can further improve the motor-learning effect.

Arm elevation movement is used in daily living. There are many reports about the functions of the muscle activities and biomechanics of the shoulder joint. However, there are few reports about trunk function during arm elevation movement. We have performed physical therapy for patients without shoulder joint problems who had difficulty with arm elevation movement. We think trunk function is important in arm elevation movement. Therefore, we examined trunk function during arm elevation movement, and describe it in this report.

The activity of the gluteus maximus is said to change with exercise, the hip joint position, and muscle fiber. Therefore, it is important for physical therapy to deepen the understanding of the muscle activities of the upper and lower gluteus maximus in basic movements. In this paper, we examined the muscle activity patterns of the upper and lower gluteus maximus in basic movements using electromyography. The activities of the upper and lower gluteus maximus were different in timing and size of muscle activity in each basic movement, and we describe them using electromyograms.

Muscle activities are measured objectively using electromyography, and we can determine the position with the highest muscle activity. I would like to share with you here clinical tips I have acquired from the detailed analysis of electromyograms. Based on electromyographic data, it seems likely that the muscle activity of the serratus anterior changes based on the position of the forearm. Therefore, we have to pay special attention to the position of the forearm during exercises for the serratus anterior.

In a clinical setting, we observed the patterns of muscle activity which change with awareness and the muscular activity which increases in order to relieve pain. Using electromyography, we observed the change in calf raise movement and the increase in movement in the perineal position when the gluteal muscle was forced to contract. We were able to inhibit excessive compensation by the erector spinae muscle group. In addition, the trunk muscles and the leg muscles became involved at the same time and contributed to correct postural alignment.

When performing a movement, many features of sensory information are used as inputs and integrated. Smooth movement is made possible by selecting the necessary information from all sensory inputs. The somatosensory input of the movement is adjusted at different levels, such as at the level of the spinal cord, brainstem, and sensory cortex. However, sensory tests used by physical therapists provide only the sensory information perceivable through parietal association fields. Further, somatosensory evoked potentials (SEPs) occur in tests of the somatic sensory function. Understanding of SEPs enables evaluation of the posterior track; therefore, it is possible to determine the occurrence of somatosensory input adjustment at any stage. A characteristic decrease in the SEP amplitude is noted with an increase in the speed and intensity of movement. Thus, it is important to understand the relationship between motor speed and somatosensory inputs. In this paper, we introduce our study of the relationship between physical movements and somatosensory inputs, and provide recommendations for physical therapy practice.

Motor imagery provides a learning effect similar to that of actual movement, and is an effective rehabilitation modality. Factors influencing brain activity are thought to include the number of repetitions, the body part moved, muscle strength, range of joint movement, perception of rhythm, and movement complexity. We theorized that a change in motor imagery complexity would also change the excitability of spinal neural function as well as brain activity. Our study of motor imagery complexity showed that the excitability of spinal neural function is increased. On the other hand, it is difficult to understand the content of motor imagery. Motor imagery ability is a factor that influences the effect of therapy. Motor imagery ability is assessed by the validity and reliability of vividness. We evaluated the influence of motor imagery ability on the excitability of spinal neural function. The results of the group with low motor imagery ability showed that the excitability of the spinal neural function is increased.

In clinical settings, we often treat pain, but the cause of pain is often not clear. We sometimes use X-ray images to identify the cause of pain. However, symptoms and X-ray images are not necessarily consistent. Therefore, a basic understanding of the nature of pain is necessary. We must learn how damaged tissue is restored, and the organization of healthy tissue. Only then can we understand how damaged connective tissue is restored and how the percentages of the fiber and matrix components change during the repair and organization processes. Based on this anatomic knowledge, we can understand how to treat pain.

In general, muscle action is often thought of in the anatomical limb position, and there are few reports on the complex action of the muscles surrounding the hip joint in the sitting posture. Therefore, we examined the activity of the muscles surrounding the hip joint in stable internal and external rotation using electromyography (EMG). The subjects were 10 healthy males (20 lower limbs). EMG of the lower gluteus maximus, sartorius, adductor longus, and gracilis muscles was performed in the sitting posture. The activities during internal and external rotation of the hip joint at 10°, 20°, and 30° were compared. The results show that the integrated EMG activity of the lower gluteus maximus fibers at 30° of external rotation was significantly greater than that at 10°. In addition, the integrated EMG activities of the sartorius and adductor longus muscles at 30° of external rotation were significantly greater than their respective values at 10° or 20°, and their activities at 20° of external rotation were significantly greater than their respective values at 10°. Integrated EMG activities of the adductor longus and gracilis muscles at 30° of internal rotation were significantly greater than their respective values at 10° or 20°. On the basis of these results, we conclude that external rotation of the hip joint is mainly performed by the sartorius muscle, and the lower gluteus maximus fibers supplement this action. In addition, as the hip joint adductor muscles counteract hip abduction, the adductor longus is also involved in hip joint external rotation by drawing the posterior surface of the femur inward and upward. Internal rotation of the hip joint requires adduction, so the hip joint adductor muscles are involved in stabilizing the limb position.

This study examined the effect of continuous motor imagery on the accuracy of movement and assessed the relationship between the accuracy of movement and the excitability of spinal neural function in a healthy 25-year-old man. The F wave was recorded under three conditions: at rest, with the participant holding a pinch sensor, and during motor imagery. The participant practiced the pinching movement at 30% of maximum voluntary contraction for 1 min. The accuracy of movement was assessed before and after motor imagery and the values were compared. The results show that the F-wave persistence and F/M amplitude ratio tended to increase during motor imagery compared to the values recorded in the resting and sensor-holding conditions, and the accuracy of movement tended to increase during continuous motor imagery. In addition, the excitability of the spinal neural function may be related to the accuracy of movement.

In this study, we examined the relationship between the activity pattern of hamstring muscles and postural change of weight shift, in the standing position. We used surface electromyographic data from the medial gluteus medius, biceps femoris, and semitendinosus muscles of 10 healthy male participants. During exercise tasks, we observed two groups of participants: those who registered ankle dorsiflexion during lateral weight shift movements and those who did not. The former group registered an increase in hamstring muscle activity and the latter group registered no change. Similar to a previous study, an increase in gluteus medius muscle activity was detected along with the start of lateral weight shift. It appears that the biceps femoris muscle works to increase hip extension before semitendinosus muscle activity, causing a forward weight shift and dorsiflexion of the ankle joint during lateral weight shift in the standing position.

This study examined the effect of acupuncture stimulation physical therapy (ASPT) with the inhibition technique on the excitability of the spinal neural function in healthy subjects with high muscle tonus. This study recruited 16 healthy subjects. In the ASPT group, ASPT with the inhibition technique was applied at LU5 (Chize) during left thenar muscle activity of 30% maximal voluntary contraction (ASPT trial). The F-waves were recorded in three trials: during rest (resting), during ASPT (ASPT), and after ASPT (post ASPT). For the control, F-waves were recorded without using ASPT (post no ASPT) in a similar way on a different day. The relative value of F-wave persistence significantly decreased in the post ASPT trial compared with the post no ASPT trial. ASPT with the inhibition technique at LU5 (Chize) inhibited the excitability of the spinal neural function in healthy subjects with high muscle tonus.

In this study, we examined the effect on the excitability of the spinal neural function of motor imagery in the thumb and index finger opposition position with opponens orthosis. We analyzed 10 healthy subjects. In the motor imagery with orthosis trial, F-waves were recorded during relaxation (rest trial). Subsequently, the subjects practiced isometric thenar muscle activity at 30% maximum voluntary contraction using visual feedback for 1 min. Then, F-waves were recorded while the subjects performed motor imagery in the opposition position with orthosis (image with orthosis trial). After the motor imagery task, F-waves were recorded during relaxation (post-image trial). In the motor imagery without orthosis trial, F-waves were recorded during rest, image without orthosis, and post-image trials on another day. The relative values of persistence and F/M amplitude ratio during the image with orthosis trial were significantly higher than those of the without orthosis trial. Motor imagery with proprioceptive input can increase the excitability of spinal neural function. In clinical settings, it is important to perform motor imagery in a position similar to that during actual activity.

This study aimed to examine differences in the index of kyphosis, center of foot pressure position, and sway in the standing position according to fall direction and frequency. A total of 78 community-dwelling elderly subjects with the ability to walk indoors were classified into three groups: Group I, those who had no falls in the past year; Group II, those who had experienced falls other than backward falls in the past year; and Group III, those who had experienced backward falls in the past year. The following were measured: index of kyphosis in the standing position, eyes-open Y-axis average displacement (average displacement YA), eyes-closed Y-axis average displacement (average displacement YB), eyes-open rectangular sway area (rectangular area A), eyes-closed rectangular sway area (rectangular area B), eyes-open center of gravity locus length (trajectory length A), eyes-closed center of gravity locus length (trajectory length B), and the Romberg ratio. No significant differences were found between the groups. Rectangular area B measured 7.7 ± 14.9 cm² for those with single falls and 9.7 ± 10.5 cm² for those with multiple falls. The gender ratio (male/female) was 7/5 for those with single falls and 4/15 for those with multiple falls. The use of a walking aid (Yes/No) was 1/11 for those with single falls and 9/10 for those with multiple falls. The differences were significant (p<0.05). There were no significant differences between the other items measured. Because it is difficult to determine the fall direction and risk in a standing posture with a static balance test, a combination of dynamic balance adjustments may be necessary. Elderly people with a large rectangular sway area in the eyes-closed standing position and elderly females who use walking aids have a greater risk of multiple falls.

This study investigated the changes in the excitability of spinal neural function due to differences between the upper limb position seen in an observation task and that of the measured upper limb. The excitability of spinal neural function was examined using the F wave. The subjects were 12 healthy adults with a mean age of 26.0 ± 5.4 years. The subjects sat on a chair with the right forearm in the neutral position with the palm facing left, or with the forearm supinated with the palm facing upwards. They watched two videos showing the movement of the right thumb from the radial side (radial video), and the palmar side (palmar video). The F wave was first recorded at rest, and then recorded for one minute while the subjects watched the radial video or palmar video with the right forearm in the neutral or supination positions after a four-minute rest. The F wave was elicited from the right thenar eminence following stimulation of the right median nerve. The results revealed that the relative amplitude of the F/M ratio in the forearm neutral position was significantly higher than that in the forearm supination position when the radial video was watched. In the palmar video task, although there was no significant difference between the relative persistence and the relative amplitude of the F/M ratio, it tended to show a higher value in the forearm supination position than in the forearm neutral position. These results suggest that the excitability of spinal neural function corresponding to the muscle of the right thenar eminence, increases when the upper limb position in the observation task and the position of the observer’s upper limb are similar.

We conducted physical therapy for a patient who underwent total left knee arthroplasty for osteoarthritis. The ability to stand up from the half-kneeling position was necessary to enable the patient to return to nursing work. At the beginning of the therapy program, the patient could not fully extend either of the lower extremities or stand up from the half-kneeling position. Physical therapy included exercises for improving standing ability from various half-kneeling position heights, as well as range of motion and muscle strengthening exercises. After 4 weeks of exercise, the patient was able to stand up from a half-kneeling position without difficulty or assistance. This case report highlights the benefits of a modified physical therapy program.

This case report describes a patient with femoral neck fracture and body instability in the forward direction at the end of the stance phase during walking. Physical therapy for this patient included both muscle strength training of the hip extensor muscles and weight-transfer exercises with reaching movements using one upper limb while holding a T-cane. With physical therapy, weight transfer in the forward direction during the stance phase accompanied hip extension. Moreover, forward body instability at the end of the stance phase disappeared and walking ability improved. The effects of physical therapy for this patient are discussed with reference to improvements in joint angle values.

We administered physical therapy for a patient who presented with right hemiplegia after cerebral infarction. When lowering clothing with the left hand for toileting, the patient risked falling posteriorly to the right. Therefore, therapy focused on enabling the removal of underclothing. Healthy subjects remove underclothing with the use of left elbow extension and left lateral bending of the trunk, while moving the pelvis in a right lateral direction. However, this patient was unable to adequately bend the trunk to the left and could not lower underclothing on the left side. In addition to not being able to control right lateral movement of the pelvis, she had rearward displacement of the right buttock, and risked falling posteriorly to the right. Physical examination and observation of motion revealed decreased tone of the right external abdominal oblique and the posterior fibers of the gluteus medius; the lower fibers of the gluteus maximus were considered the main problem. Physical therapy enabled the patient to undress for self-toileting by focusing on the impaired muscles.

We performed physical therapy for a patient with left hemiplegia following cerebral infarction 4 years earlier. The patient had excess outward posterolateral tilt in the left leg stance during walking. Moreover, the pelvis tilted down and to the right with adduction of the left hip because of the progressive outward lateral left lower-leg tilt. The patient's gait motion showed an early initial contact on the left side. Abnormal motion was observed, with excess tone in the left peroneal and tibialis posterior muscles. Furthermore, left ankle dorsiflexion was restricted. Accordingly, we prescribed direct stretching for the left tibialis posterior and facilitation of the left peroneal muscles. However, the pelvic tilt to the right and adduction of the left hip showed no improvement. Therefore, the pelvic tilt to the right and adduction of the left hip were not caused by the ankle and foot problem. On re-examination, abnormal motion was observed, with abnormal muscle tone for horizontal driving on the left internal oblique muscle of the abdomen. Physical therapy was performed to address this trunk, ankle, and foot condition. Consequently, the patient showed improvement in left lower-leg excess outward posterolateral tilt, and pelvic tilt down and to the right, along with adduction of the left hip. Moreover, the patient attained stability in the left leg stance during walking.

A patient with cervical spinal canal stenosis who had right shoulder pain when removing a front-opening shirt was prescribed physical therapy. We showed the patient how to undress by grasping the right hem of the front-opening shirt. When undressing, the patient exhibited poor right shoulder external rotation when pulling on the right upper garment, and rightward rotation of the thoracolumbar spine caused the right hand to move back and to the outside. Thus, the right shoulder was displaced backward, and the right scapular arch was elevated with shoulder flexion. When removing the right collar, the right scapular arch was raised further with flexion to lower the right shoulder. With right shoulder extension and external rotation and right elbow extension while maintaining the right scapular arch in the flexion position, pain was induced in the biceps long head tendon in the intertubercular sulcus by a tension load; and this pain interfered with undressing. Based on these observations, we prescribed physical therapy for right shoulder and scapular arch impairment. Right shoulder external rotation induced right hand movement toward the back and outside, and the right upper garment was placed under tension. Thus, the patient was able to remove the right collar and lower the scapular arch without pain when undressing.

We performed physical therapy for a patient with left hemiplegia after cerebral infarction. The patient had reduced safety and stability because of a tendency to fall to the left when gargling while seated in a wheelchair. The patient’s wheelchair sitting position showed posterior tilt of the pelvis due to poor left hip flexion, with further depression of the pelvis on the left and leftward tilt of the trunk on abduction of the left hip. Therefore, the patient’s wheelchair sitting position showed excessive leaning into the backrest on the left. The patient was able to hold water in his mouth in this position, but when he spat out the water, the thoracic vertebrae showed excessive flexion due to poor left hip flexion. Thus, the patient fell to the left when the trunk lifted away from the backrest, compromising safety and stability in the sitting position. To enable the patient to gargle safely, we trained him to keep a symmetrical sitting position, with forward tilt of the pelvis using hip flexion while preparing to spit. Because the patient had cognitive impairment, physical therapy was challenging. By involving the family, we were able to perform physical therapy. As a result, the patient was able to keep a symmetrical wheelchair sitting position with improved safety when gargling, despite the challenge posed by the patient’s cognitive impairment.

Patients who undergo femoral head replacement may have difficulty in dressing with socks because excessive hip motion can dislocate the joint. We describe a patient who underwent surgery for a fractured left femoral neck and had difficulty putting on and removing socks. He could not abduct his hip with the joint flexed at 90° and felt pain near the greater trochanter with movement to the end of internal rotation with abduction. Therefore, he was instructed to turn leftward and to the rear in the standing position. As a result, he was able to put on and remove socks without pain.

We prescribed physical therapy for a patient with right hemiplegia following cerebral infarction 9 years prior. The patient had excess lower leg tilt to the outside in the right leg stance during walking. This interfered with safety and stability in the right leg stance. With motion, abnormal tone was observed in the right peroneal muscle and foot invertors. We prescribed direct stretching for the right foot invertors and facilitation for the right peroneal muscle. The patient showed improvement in the right leg tilt to the outside. Moreover, the patient gained safety and stability in the right leg stance during walking.

Physical therapy was performed for a patient with left hemiplegia following cerebral infarction. The patient had difficulty extending the thoracic and lumbar spine after bending forward when moving to stand up. Difficulty with thoracic spinal flexion appeared to be due to increased longis-simus thoracis tone. Moreover, decreased left gluteus maximus tone prevented braking of anterior thoracic flexion. Accordingly, physical therapy was performed for the left gluteus maximus and thoracic and lumbar spinal muscles. As a result, muscle tone increased in the lower fibers of the left gluteus maximus, and braking of anterior thoracic flexion recovered as left hip joint flexion improved, enabling the patient to stand up with less difficulty.