OBJECTIVES: To explore the changes of elbow flexor muscle strength after musculocutaneous nerve injury and its correlation with needle electromyography (nEMG) parameters. METHODS: Thirty cases of elbow flexor weakness caused by unilateral brachial plexus injury (involving musculocutaneous nerve) were collected. The elbow flexor muscle strength was evaluated by manual muscle test (MMT) based on Lovett Scale. All subjects were divided into Group A (grade 1 and grade 2, 16 cases) and Group B (grade 3 and grade 4, 14 cases) according to their elbow flexor muscle strength of injured side. The biceps brachii of the injured side and the healthy side were examined by nEMG. The latency and amplitude of the compound muscle action potential (CMAP) were recorded. The type of recruitment response, the mean number of turns and the mean amplitude of recruitment potential were recorded when the subjects performed maximal voluntary contraction. The quantitative elbow flexor muscle strength was measured by portable microFET 2 Manual Muscle Tester. The percentage of residual elbow flexor muscle strength (the ratio of quantitative muscle strength of the injured side to the healthy side) was calculated. The differences of nEMG parameters, quantitative muscle strength and residual elbow flexor muscle strength between the two groups and between the injured side and the healthy side were compared. The correlation between elbow flexor manual muscle strength classification, quantitative muscle strength and nEMG parameters was analyzed. RESULTS: After musculocutaneous nerve injury, the percentage of residual elbow flexor muscle strength in Group B was 23.43% and that in Group A was 4.13%. Elbow flexor manual muscle strength classification was significantly correlated with the type of recruitment response, and the correlation coefficient was 0.886 (P<0.05). The quantitative elbow flexor muscle strength was correlated with the latency and amplitude of CMAP, the mean number of turns and the mean amplitude of recruitment potential, and the correlation coefficients were -0.528, 0.588, 0.465 and 0.426 (P<0.05), respectively. CONCLUSIONS The percentage of residual elbow flexor muscle strength can be used as the basis of muscle strength classification, and the comprehensive application of nEMG parameters can be used to infer quantitative elbow flexor muscle strength.
Humans ; Elbow ; Electromyography ; Musculocutaneous Nerve ; Elbow Joint/physiology* ; Muscle, Skeletal ; Muscle Strength ; Peripheral Nerve Injuries

Three-dimensional finite element model of elbow was established to study the effect of medial collateral ligament (MCL) in maintaining the stability of elbow joint. In the present study a three-dimensional geometric model of elbow joint was established by reverse engineering method based on the computed tomography (CT) image of healthy human elbow. In the finite element pre-processing software, the ligament and articular cartilage were constructed according to the anatomical structure, and the materials and contacts properties were given to the model. In the neutral forearm rotation position and 0° flexion angle, by comparing the simulation data of the elbow joint with the experimental data, the validity of the model is verified. The stress value and stress distribution of medial collateral ligaments were calculated at the flexion angles of elbow position in 15°, 30°, 45°, 60°, 75°, 90°, 105°, 120°, 135°, respectively. The result shows that when the elbow joint loaded at different flexion angles, the anterior bundle has the largest stress, followed by the posterior bundle, transverse bundle has the least, and the stress value of transverse bundle is trending to 0. Therefore, the anterior bundle plays leading role in maintaining the stability of the elbow, the posterior bundle plays supplementary role, and the transverse bundle does little. Furthermore, the present study will provide theoretical basis for clinical recognizing and therapy of elbow instability caused by medial collateral ligament injury.
Biomechanical Phenomena ; Cadaver ; Collateral Ligaments ; physiology ; Elbow Joint ; physiology ; Finite Element Analysis ; Humans ; Range of Motion, Articular ; Tomography, X-Ray Computed

Muscle strength training plays an important role in improving limb movement function, preventing muscle atrophy and promoting muscle function recovery in patients with various bone and joint diseases. The sports function of elbow joint is closely related to people's daily life activity ability. At present, Chinese muscle strength training devices are depended on import. Therefore, it is of great significance to develop muscle strength training devices. Based on the concepts and characteristics of isometric training, isotonic training, passive training and isokinetic training, in the upper computer, the servo driver and servo motor are controlled through the LabView interface, and the real-time torque is detected by the torque sensor, realizing four training modes. The main parameters of the multi-mode elbow joint muscle strength training device meet the requirements, and the trainers have a good experience.
Elbow Joint ; physiology ; Humans ; Muscle Strength ; Muscle, Skeletal ; Resistance Training ; Torque

Myositis ossificans circumscripta (MOC) is a kind of self-localized, benign and tumor-like lesions often seen in adults, with approximately 75% of cases caused by trauma. We reported a case of non-traumatic MOC occurred at the elbow joint in a 9-year old child and it has been excised by surgery. After 18 months follow-up, a favorable outcome has been achieved with the Broberg-Morrey score of 100. We suggest that surgical resection should be done as soon as the diagnosis is confirmed.
Arthralgia ; diagnostic imaging ; physiopathology ; Biopsy, Needle ; Child ; Elbow Joint ; diagnostic imaging ; pathology ; surgery ; Follow-Up Studies ; Humans ; Immunohistochemistry ; Magnetic Resonance Imaging ; methods ; Male ; Myositis Ossificans ; diagnostic imaging ; surgery ; Orthopedic Procedures ; methods ; Pain Measurement ; Postoperative Care ; methods ; Range of Motion, Articular ; physiology ; Tomography, X-Ray Computed ; methods ; Treatment Outcome

BACKGROUNDThe appropriate elbow position of short-segment nerve conduction study (SSNCS) to diagnose cubital tunnel syndrome (CubTS) is still controversial. The goal of this study was to determine the effect of different elbow positions at full extension and 70° flexion on SSNCS in CubTS.

METHODSIn this cross-sectional study, the clinical data of seventy elbows from 59 CubTS patients between September, 2011 and December, 2014 in the Peking University First Hospital were included as CubTS group. Moreover, thirty healthy volunteers were included as the healthy group. SSNCS were conducted in all subjects at elbow full extension and 70° elbow flexion. Paired nonparametric test, bivariate correlation, Bland-Altman, and Chi-squared test analysis were used to compare the effectiveness of elbow full extension and 70° flexion elbow positions on SSNCS in CubTS patients.

RESULTSData of upper limit was calculated from healthy group, and abnormal latency was judged accordingly. CubTS group's latency and compound muscle action potential (CMAP) of each segment at 70° elbow flexion by SSNCS was compared with full extension position, no statistically significant difference were found (all P > 0.05). Latency and CMAP of each segment at elbow full extension and 70° flexion were correlated (all P < 0.01), except the latency of segment of 4 cm to 6 cm above elbow (P = 0.43), and the latency (P = 0.15) and the CMAP (P = 0.06) of segment of 2 cm to 4 cm below elbow. Bivariate correlation and Bland-Altman analysis proved the correlation between elbow full extension and 70° flexion. Especially in segments across the elbow (2 cm above the elbow and 2 cm below it), latency at elbow full extension and 70° flexion were strong direct associated (r = 0.83, P < 0.01; r = 0.55, P < 0.01), and so did the CMAP (r = 0.49, P < 0.01; r = 0.72, P < 0.01). There was no statistically significant difference in abnormality of each segment at full extension as measured by SSNCS compared with that at 70° flexion (P > 0.05, respectively).

CONCLUSIONSThere was no statistically significant difference in the diagnosis of CubTS with the elbow at full extension compared with that at 70° flexion during SSNCS. We suggest that elbow positon at full extension can also be used during SSNCS.

Action Potentials ; Adolescent ; Adult ; Aged ; Aged, 80 and over ; Cross-Sectional Studies ; Cubital Tunnel Syndrome ; physiopathology ; Elbow ; Female ; Humans ; Male ; Middle Aged ; Neural Conduction ; physiology

PURPOSE: To verify the effect of a newly-developed cylindrical type forearm brace, which was designed to give focal counterforce perpendicularly on the muscle belly of the wrist extensor. MATERIALS AND METHODS: The dominant hands of 24 (12 males, 12 females) healthy subjects were tested. Two types of forearm braces (focal cylindrical type and broad pneumatic type) were examined. The braces were applied at the extensor carpi radialis brevis, 5 to 7 cm distal to the lateral epicondyle. Two surface electrodes were attached to the proximal and distal parts of the brace. By quantitative electromyography, the mean amplitudes of voluntary extensor carpi radialis brevis contraction before and after applying each brace were recorded and analyzed. RESULTS: The mean amplitudes of the focal cylindrical brace and broad pneumatic brace were reduced significantly compared to no brace (p<0.05), with a larger reduction for the cylindrical brace than the pneumatic brace (p<0.05). There was no significant difference between the proximal and distal mean amplitudes with each brace. CONCLUSION: A cylindrical type brace decreased electromyographic activity in the wrist extensor more effectively than did the pneumatic type brace.
Adult ; *Braces ; *Electromyography ; Equipment Design ; Female ; Forearm/physiology ; Humans ; Male ; Middle Aged ; Tennis Elbow/physiopathology/therapy ; Wrist/*physiology ; Wrist Joint ; Young Adult

Tuberculosis (TB) occurring after a closed bone fracture in the patient with no history of TB and no evidence of TB infection at the time of initial fracture is a rare entity. We report one such case of a 48-year-old female, who presented in the emergency department with an olecranon fracture which was open reduced and internally fixed with tension band wiring. Patient presented in the outpatient department with serosanguineous discharge at 3 weeks after surgery. The discharge was sent for culture and sensitivity tests, and the patient was managed by antibiotics and daily dressings. There was wound dehiscence and the underlying implant was exposed, which was removed at 12 weeks after surgery. Repeat debridements and dressings continued for 6 months, but the discharge from the wound site continued. X-rays of the elbow performed at 6 months raised the suspicion of TB, which was confirmed by Ziel-Neelsen staining and histopathological examination of the debrided tissue. Following the confirmation, patient was put on antitubercular drugs. The patient responded to antitubercular drug therapy (ATT), the purulent discharge from the wound ceased, and eventually the wound healed after 2 months of starting ATT.
Arthritis, Infectious ; etiology ; Elbow Joint ; Female ; Fracture Fixation, Internal ; Humans ; Middle Aged ; Olecranon Process ; injuries ; Postoperative Complications ; Transforming Growth Factor beta1 ; physiology ; Tuberculosis, Osteoarticular ; etiology

BACKGROUND: Although closed reduction and percutaneous pinning is accepted as the treatment of choice for displaced supracondylar fracture of the humerus, there are some debates on the pinning techniques, period of immobilization, elbow range of motion (ROM) exercise, and perceptions on the restoration of elbow ROM. This study was to investigate the consensus and different perspectives on the treatment of supracondylar fractures of the humerus in children. METHODS: A questionnaire was designed for this study, which included the choice of pinning technique, methods of elbow motion, and perception on the restoration of elbow ROM. Seventy-six orthopedic surgeons agreed to participate in the study and survey was performed by a direct interview manner in the annual meetings of Korean Pediatric Orthopedic Association and Korean Society for Surgery of the Hand. There were 17 pediatric orthopedic surgeons, 48 hand surgeons, and 11 general orthopedic surgeons. RESULTS: Ninety-six percent of the orthopedic surgeons agreed that closed reduction and percutaneous pinning was the treatment of choice for the displaced supracondylar fracture of the humerus in children. They showed significant difference in the choice of pin entry (lateral vs. crossed pinning, p = 0.017) between the three groups of orthopedic surgeons, but no significant difference was found in the number of pins, all favoring 2 pins over 3 pins. Most of the orthopedic surgeons used a removable splint during the ROM exercise period. Hand surgeons and general orthopedic surgeons tended to be more concerned about elbow stiffness after supracondylar fracture than pediatric orthopedic surgeons, and favored gentle passive ROM exercise as elbow motion. Pediatric orthopedic surgeons most frequently adopted active ROM exercise as the elbow motion method. Pediatric orthopedic surgeons and general orthopedic surgeons acknowledged that the patient's age was the most contributing factor to the restoration of elbow motion, whereas hand surgeons acknowledged the amount of injury to be the most contributing factor. CONCLUSIONS: More investigation and communication will be needed to reach a consensus in treating pediatric supracondylar fractures of the humerus between the different subspecialties of orthopedic surgeons, which can minimize malpractice and avoid medicolegal issues.
Age Factors ; Attitude of Health Personnel ; Bone Nails ; Chi-Square Distribution ; Child ; Consensus ; Elbow Joint/physiology ; Exercise Therapy/*methods ; Fracture Fixation, Internal/*methods ; Humans ; Humeral Fractures/rehabilitation/*surgery ; Orthopedics ; Questionnaires ; *Range of Motion, Articular ; Splints ; Statistics, Nonparametric ; Time Factors

BACKGROUND: Although closed reduction and percutaneous pinning is accepted as the treatment of choice for displaced supracondylar fracture of the humerus, there are some debates on the pinning techniques, period of immobilization, elbow range of motion (ROM) exercise, and perceptions on the restoration of elbow ROM. This study was to investigate the consensus and different perspectives on the treatment of supracondylar fractures of the humerus in children. METHODS: A questionnaire was designed for this study, which included the choice of pinning technique, methods of elbow motion, and perception on the restoration of elbow ROM. Seventy-six orthopedic surgeons agreed to participate in the study and survey was performed by a direct interview manner in the annual meetings of Korean Pediatric Orthopedic Association and Korean Society for Surgery of the Hand. There were 17 pediatric orthopedic surgeons, 48 hand surgeons, and 11 general orthopedic surgeons. RESULTS: Ninety-six percent of the orthopedic surgeons agreed that closed reduction and percutaneous pinning was the treatment of choice for the displaced supracondylar fracture of the humerus in children. They showed significant difference in the choice of pin entry (lateral vs. crossed pinning, p = 0.017) between the three groups of orthopedic surgeons, but no significant difference was found in the number of pins, all favoring 2 pins over 3 pins. Most of the orthopedic surgeons used a removable splint during the ROM exercise period. Hand surgeons and general orthopedic surgeons tended to be more concerned about elbow stiffness after supracondylar fracture than pediatric orthopedic surgeons, and favored gentle passive ROM exercise as elbow motion. Pediatric orthopedic surgeons most frequently adopted active ROM exercise as the elbow motion method. Pediatric orthopedic surgeons and general orthopedic surgeons acknowledged that the patient's age was the most contributing factor to the restoration of elbow motion, whereas hand surgeons acknowledged the amount of injury to be the most contributing factor. CONCLUSIONS: More investigation and communication will be needed to reach a consensus in treating pediatric supracondylar fractures of the humerus between the different subspecialties of orthopedic surgeons, which can minimize malpractice and avoid medicolegal issues.
Age Factors ; Attitude of Health Personnel ; Bone Nails ; Chi-Square Distribution ; Child ; Consensus ; Elbow Joint/physiology ; Exercise Therapy/*methods ; Fracture Fixation, Internal/*methods ; Humans ; Humeral Fractures/rehabilitation/*surgery ; Orthopedics ; Questionnaires ; *Range of Motion, Articular ; Splints ; Statistics, Nonparametric ; Time Factors

The architecture and dynamic properties of human muscles are very complex. So, most of the muscles are represented simply by straight-line or curve in musculoskeletal model. The straight-line and curve are called muscle paths. The representation of the muscle path plays a vital role in musculoskeletal model simulation such as the estimation of muscle force. Firstly, we create a black box with the muscle force on the bones as the output signal. Then based on the assumption that there is a muscle path plane (MPP) at any time during joint movement, we construct the space curve function of the muscle path during joint instantaneous movement by mathematical approaches. Finally, we calculate the lengths of the muscle paths and analyze the changes of them during elbow flexion.
Algorithms ; Computer Simulation ; Elbow Joint ; physiology ; Humans ; Models, Anatomic ; Movement ; Muscle Contraction ; Muscle, Skeletal ; physiology