Muscle strength in rheumatoid elbow: quantitative measurement and comparison to Larsen's X-ray grade

Accurate assessment of elbow function is important to determine the total ability of the arm. The purpose of this study was to clarify the relationship between isometric muscle strength of the elbows of patients with rheumatoid arthritis (RA) and Larsen's X-ray evaluation. Fifty-six elbows of 45 RA patients aged 47 to 77 years (mean age, 63 years) were tested. Muscle strength was measured with an isometric torque-cell dynamometer. Test-retest reliability of the dynamometer was proven by measuring 12 elbows of 6 healthy young men. In RA patients, elbow flexion and extension strength decreased in proportion to increases in the severity of Larsen's grades from Grade 1 to 4. However, Grade 5 elbows had greater muscle strength than those in Grade 4. Forearm pronation and supination strength also decreased in proportion to increases in the severity of Larsen's grades from Grade 1 to 5. This quantitative study made it clear that the muscle strength of RA patients' elbows almost completely correlates to X-ray finding according to the grade of Larsen's evaluation based on X-rays. With regard to muscle strength of postoperative elbows, both flexion strength and supination strength after total elbow replacement (TER) were about two times greater than before TER, and after synovectomy it was as great as those in non-operative RA patients of Grade 2.     

The effect of a flexion contracture of the elbow on the ability to transfer in patients who have quadriplegia at the sixth cervical level

We studied six patients (twelve upper extremities) who had quadriplegia at the sixth cervical level. Our purpose was to evaluate how the loss of terminal extension of the elbow adversely affected the ability of the patient to perform transfers with a sliding board and so-called depression raises (lifting of the body with use of the extended upper extremities to reduce the pressure on the ischial tuberosities). Function of the triceps muscle was considered to be absent in eight upper extremities and present in four. A flexion contracture of the elbow was simulated with use of a specially fabricated, hinged elbow brace. Terminal extension was progressively limited, in 5-degree increments, until the patient was no longer able to perform the transfer or the depression raise. The mean flexion contracture at which the patient could not perform the transfer or the depression raise was approximately 25 degrees when function of the triceps was absent and approximately 50 degrees when function of the triceps was intact. The results of this study emphasize the importance of maintaining the full range of motion of the elbow in a patient who has high-level quadriplegia. In a patient who has quadriplegia at the sixth cervical level who otherwise would be independent with regard to transfer skills and mobility in bed, a flexion contracture of the elbow of approximately 25 degrees or more can result in the loss of a functional level and render the patient as dependent as one who has quadriplegia at the fifth cervical level.     

Surveillance of nosocomial infections in geriatric patients

The authors report 18 cases of transfer of several ulnar nerve fascicles onto the biceps muscle nerve, performed between 1990 and 1997. The patients were between the ages of 17 and 41 years, and presented C5-C6 paralysis in 8 cases and C5-C6-C7 paralysis in 10 cases. The operation was tempted between 4 months and 6 years (m = 17 months) after the initial accident. In the 8 cases of C5-C6 paralysis reviewed, 7 patients recovered elbow flexion and only one required an additional Steindler transfer. In the 9 cases of C5-C6-C7 paralysis reviewed, 4 patients recovered elbow flexion after nerve surgery alone, while 4 patients only obtained elbow flexion after a complementary Steindler transfer. Two of these 4 patients were operated very late (27 and 75 months). Finally, a single 40-year-old patient, operated 28 months after the accident, was considered to be a complete failure. Overall, ulnar biceps nerve transfer appears to be indicated in C5-C6 avulsion, during the months following the initial accident. Flexion against gravity is then regularly obtained in less than 6 months, without any objective or subjective sequelae of the hand.     

Obstetrical brachial plexus palsy: results following neurolysis of conducting neuromas-in-continuity

Sixteen infants with conducting neuromas-in-continuity at primary brachial plexus exploration underwent microsurgical neurolysis of their lesions. For each patient, the immediate preoperative scores for individual joint movements were compared with scores at the last examination. In the Erb's palsy group (n = 9), significant improvement was seen in shoulder movements, elbow flexion, supination, and wrist extension (paired t test, p < 0.05). Clinically useful improvements in function was seen at the shoulder and elbow (Fisher's exact test, p < 0.05). In the total palsy group (n = 7), significant improvement in shoulder abduction, shoulder adduction, elbow flexion, and extension of the wrist, fingers, and thumb was seen (paired t test, p < 0.05), but there was no significant improvement in the proportion of patients with useful functional outcomes. Neurolysis in Erb's palsy improves both muscle grade and the functional ability of patients. Neurolysis does not provide useful functional recovery in patients with total plexus palsy.     

Lipid and lipoprotein distributions in children by ethnic group, gender, and geographic location--preliminary findings of the Child and Adolescent Trial for Cardiovascular Health (CATCH)

Male and female isometric strength curves for elbow fixation, shoulder flexion, and wrist supination-pronation are obtained during systematic variation in arm configuration. The shape of a given moment-angle curve is found to be a function of the orientations of joints kinematically coupled to the primary joint. It is also found that female elbow strength curves are shifted toward flexion with respect to male elbow-strength curves, suggesting that the in situ rest length of upper-limb muscles relative to joint angle may be longer for males than for females. Experimental results were contrasted with simulation results obtained using a three-dimensional musculoskeletal model which estimates the relationships between initial joint orientations, muscle tension-length behavior, and joint moments. In most of the cases, simulation results complimented experimental data and provided insights into likely in situ muscle rest lengths and moments arms, especially for the multiarticular biceps brachii muscle. Where inconsistencies exist between simulated and experimental data, subtle biomechanical complexities within the forearm and the shoulder girdle complex are identified that require future investigation.     

Examples of recapitulation of the phylogenetic stages of development of the wakefulness-sleep cycle in mammalian ontogenesis

The purpose of this study was to determine the relationship between the ulnar nerve and the cubital tunnel during flexion of the elbow with use of magnetic resonance imaging and measurements of intraneural and extraneural interstitial pressure. Twenty specimens from human cadavera were studied with the elbow in positions of incremental flexion. With use of magnetic resonance imaging, cross-sectional images were made at each of three anatomical regions of the cubital tunnel: the medial epicondyle, deep to the cubital tunnel aponeurosis, and deep to the flexor carpi ulnaris muscle. The cross-sectional areas of the cubital tunnel and the ulnar nerve were calculated and compared for different positions of elbow flexion. Interstitial pressures were measured with use of ultrasonographic imaging to allow a minimally invasive method of placement of the pressure catheter, both within the cubital tunnel and four centimeters proximal to it, at 10-degree increments from 0 to 130 degrees of elbow flexion. As the elbow was moved from full extension to 135 degrees of flexion, the mean cross-sectional area of the three regions of the cubital tunnel decreased by 30, 39, and 41 per cent and the mean area of the ulnar nerve decreased by 33, 50, and 34 per cent. These changes were significant in all three regions of the cubital tunnel (p < 0.05). The greatest changes occurred in the region beneath the aponeurosis of the cubital tunnel with the elbow at 135 degrees of flexion. The mean intraneural pressure within the cubital tunnel was significantly higher than the mean extraneural pressure when the elbow was flexed 90, 100, 110, and 130 degrees (p < 0.05). With the elbow flexed 130 degrees, the mean intraneural pressure was 45 per cent higher than the mean extraneural pressure (p < 0.001). Similarly, with the elbow flexed 120 degrees or more, the mean intraneural pressure four centimeters proximal to the cubital tunnel was significantly higher than the mean extraneural pressure (p < 0.01). Relative to their lowest values, intraneural pressure increased at smaller angles of flexion than did extraneural pressure, both within the cubital tunnel and proximal to it. With the numbers available, we could not detect any significant difference in intraneural pressure measured, either at the level of the cubital tunnel or four centimeters proximal to it, after release of the aponeurotic roof of the cubital tunnel.     

Nerve transfer to biceps muscle using a part of the ulnar nerve in brachial plexus injury (upper arm type): a report of 32 cases

Thirty-two patients with absent elbow flexion secondary to brachial plexus injury underwent nerve transfer using 1 or 2 fascicles of the ulnar nerve to the motor branch of the biceps muscle. Twenty-six patients had root avulsion injury of C5 and C6; 4 had root avulsion injury of C5, C6, and C7; and 2 had lateral and posterior cord injury with distal injury of the musculocutaneous nerve. The follow-up period ranged from 11 to 40 months (average, 18 months). Thirty patients had biceps strength of M4 (flexion power ranged from 0.5 to 7 kg) and 1 had biceps strength of M3. All but 1 patient demonstrated signs of recovery of the biceps muscle. No notable impairment of hand function was observed.     

Restoration of elbow flexion 16 years after brachial plexus root avulsion

To restore elbow flexion in brachial plexus lesions or cervical root avulsions, surgical nerve reconstruction can be attempted after approximately 6 months. If the reconstruction is not successful or was not performed, tendon transfer may improve the function of a paralysed limb. The selection of the muscle for transfer can be influenced by strengthening potentially available muscles by a myo-feedback method.     

Increase of 5-HT7 (serotonin-7) and 5-HT1A (serotonin-1A) receptor mRNA expression in rat hippocampus after adrenalectomy

Kinematic and electromyographic (EMG) analysis of a target-directed, maximal velocity movement was used to investigate the effects of high-force eccentric exercise on the neuromuscular control of elbow flexion. Ten non-weight-trained females [19.6 (1.6) years old] performed 50 maximal velocity elbow flexion movements from 0 to 1.58 rad (90 degrees), as rapidly as possible in response to a light stimulus, while kinematic and triphasic EMG parameters were measured. This was done three times pre-exercise, immediately and 1, 2, 3, 4, and 5 days following the 50 maximal eccentric elbow flexion actions. The eccentric exercise caused lengthening of kinematic parameters including total movement time and time to peak velocity. The EMG elements of the biceps brachii (b.) motor time, time to peak EMG, biceps b. burst duration, and the latency period between biceps b. and triceps b. bursts were lengthened post-exercise. These changes persisted for up to 5 days post-exercise. The exercise also caused a large increase in serum creatine kinase (CK) activity. It was concluded that high-force eccentric exercise in this population caused prolonged changes in neuromuscular control that were a function of exercise-induced disruption of the skeletal muscle. Compensation in the central motor program was such that the components of the triphasic EMG pattern were systematically lengthened.     

Biomechanical evaluation of the medial collateral ligament of the elbow

Anatomical dissection and biomechanical testing were used to study twenty-eight cadaveric elbows in order to determine the role of the medial collateral ligament under valgus loading. The medial collateral ligament was composed of anterior, posterior, and occasionally transverse bundles. The anterior bundle was, in turn, composed of anterior and posterior bands that tightened in reciprocal fashion as the elbow was flexed and extended. Sequential cutting of the ligament was performed while rotation caused by valgus torque was measured. The anterior band of the anterior bundle was the primary restraint to valgus rotation at 30, 60, and 90 degrees of flexion and was a co-primary restraint at 120 degrees of flexion. The posterior band of the anterior bundle was a co-primary restraint at 120 degrees of flexion and a secondary restraint at 30 and 90 degrees of flexion. The posterior bundle was a secondary restraint at 30 degrees only. The reciprocal anterior and posterior bands have distinct biomechanical roles and theoretically may be injured separately. The anterior band was more vulnerable to valgus overload when the elbow was extended, whereas the posterior band was more vulnerable when the elbow was flexed. The posterior bundle was not vulnerable to valgus overload unless the anterior bundle was completely disrupted. The intact elbows rotated a mean of 3.6 degrees between the neutral position and the two-newton-meter valgus torque position. Cutting of the entire anterior bundle caused an additional 3.2 degrees of rotation at 90 degrees of flexion, where the effect was greatest. CLINICAL RELEVANCE: Physical findings in a patient who has an injury of the anterior bundle may be subtle, and an examination should be performed with the elbow in 90 degrees of flexion for greatest sensitivity. As the anterior bundle is the major restraint to valgus rotation, reconstructive procedures should focus on anatomical reproduction of that structure. Parallel limbs of tendon graft placed from the inferior aspect of the medial epicondyle to the area of the sublimis tubercle will simulate the reciprocal bands of the anterior bundle. Temporary immobilization with the elbow in flexion may relax the critically important anterior band of the reconstruction during healing.     

Fatigue analysis of human reinnervated muscle after microsurgical nerve repair

The reinnervated elbow flexors, biceps, and brachialis muscles were compared with the elbow flexors on the healthy opposite side in terms of muscle strength and fatigue in 10 patients who sustained sequelae of a unilateral posttraumatic brachial plexus palsy. The patients had recovered an active elbow flexion against resistance after microsurgical nerve repair. The patients were reviewed with an average postoperative followup of 12 years (range, 7.5-16 years). Despite a statistically significant difference in maximum isometric force, this study showed that after peripheral nerve repair, a partially reinnervated muscle has the same characteristics of fatigue and endurance as a normally innervated muscle, if these muscles exert the same percentage of their own maximum force.     

Reducing maternal smoking and relapse: long-term evaluation of a pediatric intervention

Simultaneous recordings of action potentials (APs) of multiple single motor units (MUs) were obtained in brachialis and biceps (caput breve) muscles during sinusoidally modulated isometric contractions of elbow flexor muscles and during sinusoidal flexion/extension movements in the elbow against a preload in the extension direction. The results show that MUs typically fire in one short burst for each sinusoidal cycle. The mean phase lead of the bursts of APs relative to a sinusoidally modulated isometric torque in the elbow joint or relative to sinusoidal movements in the elbow increases gradually with frequency. The increase of the mean phase lead during isometric contractions was very similar for all MUs and could be explained well by modeling the force production of MUs with a second-order linear low-pass system. For sinusoidal flexion/extension movements each MU reveals a specific, reproducible phase lead as a function of frequency. However, there is a large variability in phase behavior between MUs. Also, the modulation of the firing rate for sinusoidal isometric contractions versus sinusoidal movements appeared to be different for various MUs. In simultaneous recordings some MUs clearly revealed a larger firing rate in each burst for movements relative to isometric contractions, whereas other MUs revealed a smaller firing rate. This suggests that some MUs are preferentially activated during movements whereas others are preferably activated during isometric contractions. The results demonstrate task-dependent changes in the relative activation of MUs within a single muscle for sinusoidal isometric contractions and movements.     

Plasma cell and sclerosing osteomyelitis. A follow-up of 21 patients

Ten consecutive patients with incapacitating fecal incontinence were treated with 'anal dynamic graciloplasty' (transposition of the gracilis muscle around the anal canal and implantation of intramuscular electrodes connected with an implanted pulse generator, 6 weeks later) to achieve continence. We measured the gracilis muscle diameter immediately after transposition and before implantation of the stimulation device. It was found that gracilis diameter decreased from 12 (5 days after transposition) to 8 mm, 6 weeks later (mean decrease: 4 mm (95% confidence interval 3.6), n = 10, P < 0.05). In addition, morphology demonstrated a decrease of both Type I and Type II muscle fiber diameter and an increase in endomysial collagen. Despite this decrease in muscle (and muscle fiber) diameter, electrical stimulation of the transposed gracilis muscle increased the pressure into the anal canal from 37 to 55 mmHg (mean increase: 17 mmHg (95% confidence interval 6.29), P < 0.05). Fecal continence was achieved in seven (70%) of these patients. Further analysis revealed no correlations between reduction of the gracilis muscle diameter before implantation of the stimulation device and clinical outcome in terms of achieved continence and/or anal canal pressures. MRI is an excellent method to demonstrate the shape of gracilis muscle after transposition. However, the size of transposed gracilis muscle is not associated with the functional outcome.     

Muscle strength testing: evaluation of tests of explosive force production

The purpose of the study was to evaluate four tests of explosive force production (EFP). Specifically, the main aims of the study were to assess the reliability of different EFP tests, to examine their relationship with maximum muscle strength, and to explore the relationship between EFP tests and functional movement performance. After an extensive preliminary familiarization with the tasks, subjects ( n=26) were tested on maximum explosive strength of the elbow extensor and flexor muscle, as well as on rapid elbow extension and flexion movements performed in both an oscillatory and a discrete fashion. In addition to maximum force ( F(max)), four different EFP tests were assessed from the recorded force-time curves: the time interval elapsed between achieving 30% and 70% of F(max) ( F(30-70%)), the maximum rate of force development (RFD), the same value normalized with respect to F(max) (RFD/ F(max)), and the force exerted 100 ms after the contraction initiation ( F(100 ms)). Excluding F(30--70%), all remaining EFP tests revealed either good or fair reliability (intraclass correlation coefficients being within 0.8-1 and 0.6-0.8 intervals, respectively) which was also comparable with the reliability of F(max). RFD and F(100 ms) demonstrated a positive relationship with F(max), but not T(30-70%) and RFD/ F(max). Stronger elbow flexor muscles also demonstrated higher values of RFD and F(100 ms) than weaker elbow extensor muscles, while no difference was observed between either T(30-70%) or RFD/ F(max) recorded from two muscles. Despite the simplicity of the tested movement tasks, the relationship observed between the EFP tests and the peak movement velocity remained moderate and partly insignificant. It was concluded that most of the EFP tests could be reliable for assessing neuromuscular function in their muscle-force- (or, indirectly, muscle size) dependent (such as RFD and F(100 ms)), or muscle-force-independent ( T(30-70%) and RFD/ F(max)) forms. However, their "external validity" when applied to assess the ability to perform rapid movements could be questioned.     

Carcinoids of unknown origin: comparative analysis with foregut, midgut, and hindgut carcinoids

The purpose of this study was to analyze our results of surgical treatment of arthrogryposis of the elbow and to compare our tendon transfer results using range of motion (ROM) criteria versus functional use criteria. Eighteen tendon transfers for elbow flexion in 14 children with arthrogryposis with an average follow-up period of 4 years (range, 1-14 years) and 6 elbow capsulotomies with triceps lengthening in 6 children with arthrogryposis with an average follow-up period of 5 years (range, 2-9 years) were evaluated. Each child was assessed by a questionnaire regarding functional use of the upper extremity, physical examination of ROM and strength, and a videotaped activities of daily living evaluation. Tendon transfer results were classified and compared using 2 methods of evaluation: postoperative strength and ROM and effective functional use of the tendon transfer to perform activities of daily living. The 6 elbow capsulotomies improved from an average preoperative arc of 17 degrees of motion (average extension, -2 degrees; average flexion, 19 degrees) to an average final follow-up arc of 67 degrees (average extension, -25 degrees; average flexion, 92 degrees). The 18 tendon transfers evaluated by strength and ROM criteria showed 9 triceps to biceps transfers in 9 arms (7 good, 1 fair, and 1 poor), 5 pectoralis to biceps transfers in 4 arms (1 good, 3 fair, and 1 poor), and 4 latissimus dorsi to biceps transfers in 3 arms (2 good and 2 fair). Evaluation by functional use criteria gave the same result in 13 transfers and downgraded the result in 5; the downgraded results were due to resultant flexion contracture or limited functional use because the transfer was in the nondominant arm. Based on this review, optimal surgical candidates for tendon transfer are children older than 4 years, who have full passive ROM of the elbow in the dominant arm, and at least grade 4 strength of the muscle to be transferred.     

Moment arms and lengths of human upper limb muscles as functions of joint angles

Modeling of musculoskeletal structures requires accurate data on anatomical parameters such as muscle lengths (MLs), moment arms (MAs) and those describing the upper limb position. Using a geometrical model of planar arm movements with three degrees of freedom, we present, in an analytical form, the available information on the relationship between MAs and MLs and joint angles for thirteen human upper limb muscles. The degrees of freedom included are shoulder flexion/extension, elbow flexion/extension, and either wrist flexion/extension (the forearm in supination) or radial/ulnar deviation (the forearm in mid-pronation). Previously published MA/angle curves were approximated by polynomials. ML/angle curves were obtained by combining the constant values of MLs (defined by the distance between the origin and insertion points for a specific upper limb position) with a variable part obtained by multiplying the MA (joint radius) and the joint angle. The MAs of the prime wrist movers in radial/ulnar deviation were linear functions of the joint angle (R2 > or = 0.9954), while quadratic polynomials accurately described their MAs during wrist flexion/extensions. The relationship between MAs and the elbow angle was described by 2nd, 3rd or 5th-order polynomials (R2 > or = 0.9904), with a lesser quality of fit for the anconeus (R2 = 0.9349). In the full range of angular displacements, the length of wrist, elbow and shoulder muscles can change by 8.5, 55 and 200%, respectively.     

A dynamic model for simulating movements of the elbow, forearm, an wrist

We developed a dynamic model of the upper extremity to simulate forearm and wrist movements. The model is based on the skeletal structure of the arm and is capable of elbow flexion/extension, forearm pronosupination, and wrist flexion/extension and radial/ulnar deviation movements. Movements are produced by activation of a Hill-type model of muscle, and limits on joint motion are imposed by passive moments modeled after experimental results. We investigated the muscle output force sensitivity, as well as wrist flexion/extension motion sensitivity to parameter variations. The tendon slack length and muscle fiber length were found to have the greatest influence on muscle output and flexion/extension wrist motion. The model captured the direction of the moment vectors at the wrist well, but predicted much higher moments than were measured by stimulating the paralyzed muscles of one tetraplegic subject.     

The long-term changes after the implantation of silicone breast prostheses

For a large scaled test 52 patients with anterior transposition of the ulnar nerve and 62 patients with elbow injuries were examined by questionnaire, physical examination and electroneurography. In conformity with existing literature 24 patients out of 52 suffering from cubital tunnel syndrome had an elbow trauma previously. To our great surprise in seven patients out of 46 with elbow injuries a cubital tunnel syndrome could be found for the first time. The cubital tunnel syndrome appears to be a frequent complication of elbow injuries. Besides the well known fractures of the medial epicondyle and pericondylar fractures leading to cubital tunnel syndrome, in our study fractures of the head of the radius and processus coronoideus were found quite often. Patients having typical anamnesis and complaints should be checked by electroneurography in order to permit a quick operation and to prevent incurable damages of the nerve. The diagnosis leading to operation of the elbow should however be made with greatest care. In case the operation is unavoidable, the ulnar nerve should be thoroughly checked and anterior transposition should be carried out.     

One view of the Japanese work ethic

Elbow joint disorders were studied in relation to vibration exposure and age in 74 male stone quarry workers who operated mainly chipping hammers and sometimes rock drills. They were examined for range of active motion in elbow extension and flexion, and by means of radiographs of the elbow joint. Effects of age and vibratory tool operation on the elbow joint were statistically estimated using multiple regression analysis. In the analysis of all subjects, including those aged over 60 years, age was significantly related to the range of motion in extension and to radiographic changes in both elbows, and the duration of vibratory tool operation was associated with the range of right elbow flexion. Among subjects under the age of 60 years, duration of vibratory tool operation showed a significant dose-effect relationship to the range of flexion and radiographic changes in the right elbow, but there was no significant relationship with age. The present results suggest that the operation of chipping hammers and rock drills contributes to elbow joint disorders or osteoarthrosis, even when the effect of age is taken into account. Besides vibration exposure, it may be necessary to consider various loads on the elbow joint such as firmly grasping and pressing the tool against stones with the arm bent at about 90 degrees, and carrying stones.     

Cubital tunnel syndrome pathophysiology

Cubital tunnel syndrome is the second most common peripheral compression neuropathy. The unique anatomic relationships of the ulnar nerve at the elbow place it at risk for injury. Normally with elbow range of motion, the ulnar nerve is subjected to compression, traction, and frictional forces. As the elbow is flexed the arcuate ligament elongates producing a decrease in canal volume of 55%. Intraneural and extraneural pressures increase and have been shown to exceed 200 mm Hg with elbow flexion and flexor carpi ulnaris contraction. Because the ulnar nerve courses behind the elbow axis of rotation, elbow flexion produces excursion of the nerve proximal and distal to the medial epicondyle. The ulnar nerve also elongates 4.7 to 8 mm with elbow flexion. Cubital tunnel syndrome may develop because of various factors including repetitive elbow motion, prolonged elbow flexion, or direct compression. An understanding of the anatomy and pathophysiology associated with cubital tunnel syndrome will aid in patient evaluation and determination of the appropriate treatment.