Functional ranges of motion of the wrist joint.

We have examined 40 normal subjects (20 men and 20 women) to determine the ideal range of motion required to perform activities of daily living. The amount of wrist flexion and extension, as well as radial and ulnar deviation, was measured simultaneously by means of a biaxial wrist electrogoniometer. The entire battery of evaluated tasks could be achieved with 60 degrees of extension, 54 degrees of flexion, 40 degrees of ulnar deviation, and 17 degrees of radial deviation, which reflects the maximum wrist motion required for daily activities. The majority of the hand placement and range of motion tasks that were studied in this project could be accomplished with 70 percent of the maximal range of wrist motion. This converts to 40 degrees each of wrist flexion and extension, and 40 degrees of combined radial-ulnar deviation. This study provides normal standards for the functional range of motion of the wrist.

Strength function after elbow arthroplasty.

A prospective study of elbow strength after total elbow joint arthroplasty was conducted in 27 patients (31 procedures). In this overall group, flexion strength improved 92%, pronation, 63%, and supination, 69%. Grip strength improved 35%, but there was no mean improvement in extension strength among these patients. After 27 procedures for rheumatoid arthritis, the average strength improvement of all five functions was 71% compared to a 25% improvement in four patients with nonrheumatoid involvement. Placement of the prosthetic axis of rotation proximal or anterior to the normal axis was associated with consistently poorer strength. The sample was too small to distinguish performance among prosthetic types, but the triceps-sparing approach showed consistently better strength in extension (averaging 20%) than did the other exposures.

Rupture of the tendon of the long head of the biceps brachii. Surgical versus nonsurgical treatment.

Twenty-seven shoulders (in 26 patients) that had surgical repair of a rupture of the long head of the biceps tendon between 1962 and 1981 were evaluated at three to 22 years after injury (mean, 13 years). Thirty similar patients had been treated nonsurgically and were evaluated two to 15 years (mean, 4.6 years) after tendon rupture. Biomechanical testing was performed on ten patients in the surgical group and 13 in the nonsurgical group. Residual arm pain was infrequent in both surgically and nonsurgically treated groups. Residual subjective weakness at the elbow was reported in four of the surgical group and in 20 of the nonsurgical group. Surgically treated patients returned to work later than nonsurgical patients; however, 11 in the nonsurgical group were not able to return to full work capacity, versus only two in the surgical group. On biomechanical testing, the nonsurgical group had lost a mean of 21% of supination strength and 8% of elbow flexion strength but had no weakness in grip, pronation, or elbow extension. The surgical group had lost no strength in any of these testing modes.

Isometric elbow strength in normal individuals.

Isometric elbow strength was measured with torque cell dynamometers in a group of 104 normal subjects. Their mean age was 43 years (range, 21-79 years). Test functions included elbow flexion and extension, forearm pronation and supination, and grip. In general, the men were twice as strong as the women, and the dominant extremities were 6% stronger than the nondominant. The mean extension strength was 61% of that of flexion, and pronation was 86% of supination.

Total arthroplasty of the thumb trapeziometacarpal joint.

Considering the large number of procedures designed for the thumb trapeziometacarpal (TMC) joint, it is evident that none are completely satisfactory. Total arthroplasty attempts to improve the results of resection or space-occupying arthroplasties which, while providing good pain relief, have offered little thumb stability, strength, or normal motion. Conditions of surrounding joints indicate that this disease process is not always a straightforward clinical presentation and that a variety of surgical options are needed. When joint disease is limited to the TMC joint, bone stock is good and there is no excessive heterotopic bone. A total arthroplasty can be considered in selected patients. Careful analysis of comparative series between silicone spacers and tendon spacers for trapezium resection arthroplasty demonstrates that both pinch strength and motion are somewhat less than with total trapezial arthroplasty. Key-type pinch rarely was over 50% of the normal and averaged less than 5 kg for both interposition and silicone arthroplasty. Continued problems with implant subluxation, silicone reactive synovitis, and other complications suggest that these resections (replacement) of the trapezium are not error-free and sacrifice thumb stability. With all types of thumb reconstruction, high precision technique is required. With improved biomaterials, thumb biomechanics, and better fixation techniques, more physiologic implant arthroplasties can be anticipated to improve the current designs of total joint arthroplasties.

Rupture of the distal tendon of the biceps brachii. A biomechanical study.

In biomechanical studies on ten patients who had had a rupture of the distal tendon of the biceps brachii, we compared the results of immediate anatomical reattachment, delayed reattachment, and conservative treatment. When the tendon was simply attached to the brachialis muscle (one patient), there was nearly normal strength in elbow flexion but about 50 per cent loss of forearm supination. Late reinsertion (one patient) improved strength of both flexion and supination, but not to normal. Immediate reattachment (four patients) restored normal strength in flexion and supination at one year but not at four months (one patient). With conservative treatment (three patients) there was a mean loss of 40 per cent of supination strength and variable loss of flexion strength, averaging 30 per cent. These data suggest that immediate surgical reinsertion of the biceps tendon into the radial tuberosity, compared with other modes of treatment, restores more strength of flexion and supination.

Electromyographic analysis of the thumb: a study of isometric forces in pinch and grasp.

An electromyographic study of thumb muscles was performed on eight subjects by means of integrated polyelectromyography and simultaneous recordings of isometric flexion-extension, abduction-adduction, and prehensile pinch and grasp of the thumb. The integrated electromyographic signal proved to be an excellent index of thumb muscle activity, with a linear relationship found at low to middle levels of muscle strength. To facilitate understanding of thumb function, thumb muscles can be classified as primary or secondary on the basis of electrical potential activity. In isometric flexion, the flexor pollicis longus (FPL) was primary, whereas in extension, the extensor pollicis longus (EPL) and abductor pollicis longus were primary. In adduction, the adductor pollicis and EPL were primary and the FPL was secondary. In abduction, the abductor pollicis brevis and opponens pollicis were primary. The adductor pollicis, and FPL were nearly equal during pinch and grasp, with significant electrical activity increasing with greater force requirements. The first dorsal interosseous and EPL contributed secondarily in both pinch and grasp. When surgeons consider tendon transfers for nonfunctioning thumb muscles, the primary muscles should be replaced first to best restore pinch and grasp strength.

Objective clinical evaluation of function. Gait analysis.

Automated gait analysis allows us to document and quantify objectively normal gait, functional deficits, and patient response to therapeutic intervention. Instrumentation for this analysis at the Mayo Clinic Gait Laboratory includes three-dimensional electrogoniometers for measurement of relative joint rotation at the hip, knee, and ankle; footswitches that record foot-floor contact sequences; instrumented mats that measure step length and width; piezoelectric force plates for measurement of floor reaction forces; and two walkways that simulate a variety of ground conditions. We use a DEC-PDP 11/34 computer for acquisition, storage, and analysis of data and for generation of a gait report form that displays a patient's results relative to normal and previous evaluations. Applications of these techniques include assessment of function preoperative and postoperative total joint arthroplasty, quantification of gait faults, and documentation of effectiveness of exercise and gait training techniques. We have demonstrated the reliability of the techniques, accumulated a sizeable normal data bank, and developed a concise, effective data summary for communication with referring practitioners.

Reliability of isometric strength testing. Temporal factors and strength variation.

Isometric strength measurements of grip, pronation, supination, and elbow extension and flexion on dominant and nondominant sides were made on 40 normal subjects (age range, 40-70 years) to investigate the variability of isometric strength at different times of the day. Statistically significant differences were found in certain pronation, supination, and grip comparisons. No statistically significant difference was found in extension and flexion. Although significant, the absolute change in strength at different times of the day was small and showed no consistent trend. On the basis of these data, it appears that this variation can probably not be routinely detected in the normal clinical setting. However, the study further defines the reliability of isometric strength testing and should be considered in further attempts at more accurate measurement of elbow function. The small variations of strength, approximately 5%, that can be measured universally with sensitive testing equipment, are clinically relevant. However, when attempting to determine an impairment state in order not to place too much importance on small differences, care should be exercised in interpreting strength measurements. This investigation demonstrates how the application of sophisticated biomechanical techniques may be employed to provide useful objective information in the difficult clinical area of disability assessment. Disability judgments may be made more accurate as more is learned of the normal variables influencing objective measurement.

Objective evaluation of hand function in scleroderma patients to assess effectiveness of physical therapy.

A system was developed to evaluate the hand function of patients with scleroderma objectively in terms of joint contracture, range of movement, dexterity, strength, and skin compliance. Twelve patients with progressive systemic sclerosis were evaluated using this technique to determine the effectiveness of classic physical therapy methods. A statistically significant improvement in hand function was found after a single physical therapy treatment. This conservative mode of treatment may contribute to improved hand function in patients with scleroderma.

A biomechanical study of normal functional elbow motion.

UNLABELLED: We studied thirty-three normal patients, eighteen women and fifteen men, for normal motion and the amount of elbow motion required for fifteen activities of daily living. The amounts of elbow flexion and forearm rotation (pronation and supination) were measured simultaneously by means of an electrogoniometer. Activities of dressing and hygiene require elbow positioning from about 140 degrees of flexion needed to reach the occiput to 15 degrees of flexion required to tie a shoe. Most of these activities are performed with the forearm in zero to 50 degrees of supination. Other activities of daily living (such as eating, using a telephone, or opening a door) are accomplished with arcs of motion of varying magnitudes. Most of the activities of daily living that were studied in this project can be accomplished with 100 degrees of elbow flexion (from 30 to 130 degrees) and 100 degrees of forearm rotation (50 degrees of pronation and 50 degrees of supination). CLINICAL RELEVANCE: These data, not previously recorded, may be used to provide an objective basis for the determination of disability impairment, to determine the optimum position for elbow splinting or arthrodesis, and to assist in the design of elbow prostheses. The motion needed to perform essential daily activities is obtainable with a successful total elbow arthroplasty.

Electrogoniometer for the measurement of human elbow joint rotation.

Since the electrogoniometric method has been justified for the measurement of lower extremity joint motion, a similar device is developed for the measurement of elbow joint and forearm rotations. In this design, the axis of forearm rotation coincides with the anatomical axis which eliminates the cross talk existing in the regular triaxial goniometer. Although the axis of abduction-adduction is still offset from the elbow joint, special linkage arrangement was used to obtain equivalent motion. Experimental method was used to validate the accuracy of the device and model simulation was performed to emphasize the importance of accurate placement of the instrument on test subjects. Application of the present apparatus to normal subjects was studied to illustrate the range of elbow motion required in performing normal activities of daily living. This device is currently used in the functional evaluation of patients with elbow and forearm problems.

Hand strength measurement instruments.

A set of instruments based on strain-gage application has been designed for hand strength measurement. The reduction in size, variation in position, and ease of calibration offer a wide range of functional evaluation without causing discomfort to the subjects being examined. The strength during the entire period of functional activity can be continuously monitored. The measurement signal from the device in analogue form makes computer-aided strength evaluation possible. Above all, the construction of the devices also allows easy adaptation to different hand deformities. The instruments can be useful tools for both research and clinical evaluation.