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Biomedical subjects

J C Otis

Publications and source records attributed to J C Otis.

35 records · Page 2Linked to original sources
PubMed1989

The relationship of stride characteristics to pain before and after total knee arthroplasty.

The relationship between the changes in stride characteristics and the changes in pain that occurred before and after total knee arthroplasty (TKA) were examined in 18 patients with a diagnosis of osteoarthritis. The patients were observed after either bilateral or unilateral TKA. Measurements of stride characteristics by footswitch analysis and assessments of pain by visual analog scale were performed preoperatively and at five months and at 13 months postoperatively. Stride characteristics improved and pain diminished after surgery. Improvements, from preoperative to five months postoperative, were noted in seven of eight stride characteristics. The improvements in velocity and stride length were related to the decreases in pain over that period. Improvements from five months to 13 months postoperative were independent of the decrease in pain over that period and independent of the increase in active knee flexion angle. When evaluating stride characteristics after TKA, it is necessary to consider the effect of pain relief and to monitor the patient's ambulatory progress after pain diminishes.

Aged↗
PubMed1988

Abnormalities in quadriceps-hamstring strength. Relationships in polymyositis and dermatomyositis.

Muscle strength determined as torque was measured in patients with dermatomyositis and polymyositis. Patients demonstrated weakness in both quadriceps and hamstring muscle groups. The ratio of quadriceps to hamstring torque (Q:H) was 1.93 +/- 0.38 in controls and 1.60 +/- 0.62 in patients. Patients with Q:H ratios that were below this mean were older, weaker, and were treated with greater doses of prednisone. Fifty-six percent of patients studied initially had low Q:H ratios, and 64% of all patients had low Q:H ratios at some time. The Q:H ratio in patients with steroid and thyroid myopathy, however, was not different than controls. It is hypothesized, therefore, that preferential involvement of the quadriceps group characterizes patients with inflammatory muscle disease.

Adult↗
PubMed1987

Modification of the skin incision for the Van Nes limb rotationplasty.

The survival of patients with bone sarcomas has improved dramatically with the advent of modern chemotherapeutic regimens, fostering a present trend toward limb sparing procedures. In skeletally immature patients, prosthetic replacement of resected bones and joints is unrealistic because of continued expected growth in the limbs. A stump-lengthening procedure, the reduction-rotation-plasty, has become a valuable alternative to high above-knee amputation. A rhombus-shaped skin incision around the thigh and calf, originally described by Kotz and Salzer, led to a significant discrepancy of the circumference of the proximal and distal skin borders. A circumferential skin incision at the midthigh and a fishmouth-shaped incision at the upper calf was designed to decrease this disproportion. This incision has been used in five consecutive patients with osteosarcoma about the knee. The cosmetic results were excellent, prosthetic fittings were facilitated, and neither vascular nor wound healing problems were encountered.

Artificial Limbs↗
PubMed1986

The effect of external load on torque production by knee extensors.

The kinematics of the knee joint are load-dependent; the length of the lever arm of the extensor mechanism and the pathway of the instant center of rotation vary with external load. This study was conducted to determine if the maximum extensor torque-generating capacity of the knee joint is dependent on the distance from the knee joint at which the external force resisting extension is located. Maximum isometric extensor torques were measured at 90 and 30 degrees of knee flexion while the distance from the knee joint to the resisting force was varied. Our results demonstrated that the subjects generated larger maximum extensor torques, at both 90 and 30 degrees of knee flexion, when the external resisting force was positioned farther distal to the knee joint. This increase was as large as 50 per cent with the knee at 30 degrees of flexion.

Adult↗
PubMed1985

Energy cost during gait in osteosarcoma patients after resection and knee replacement and after above-the-knee amputation.

We determined the energy cost during gait by measuring the oxygen consumption of twenty-six patients after treatment for osteosarcoma about the knee. Fourteen had had an en bloc resection of the distal end of the femur and proximal end of the tibia followed by segmental replacement with a custom-made knee prosthesis and twelve had had an above-the-knee amputation followed by fitting with an artificial limb. Comparisons of free-walking velocity, oxygen consumption per meter traveled, and per cent of maximum aerobic capacity used during walking demonstrated that patients with resection and prosthetic knee replacement had a lower energy cost during gait.

Adolescent↗
PubMed1983

Relationship of isokinetic torque to isometric torque.

Isokinetic muscle testing has become an increasingly popular method for measuring muscle performance. However, the relationship of isokinetic strength measurements to static strength measurements remains unclear. The relationship between maximal isokinetic and maximal isometric torque was investigated at angular velocities of 24, 48, 96, and 192 degrees/s for both flexion and extension of the elbow joint. Twenty-four subjects were tested bilaterally, and discrete torque values at the positions of 60 and 90 degrees of flexion were obtained from the continuous isokinetic records for comparison with isometric torques recorded at the same two positions. Data were analyzed using an analysis of covariance with isokinetic torque, the dependent variable, expressed as a function of isometric torque and as a function of the design variables side and position. The results demonstrated significant effects of side and position and also demonstrated the dependence of isokinetic strength on velocity. Confidence intervals were determined for the prediction of isokinetic torque from observed isometric torque for normal individuals, providing a potentially useful tool to aid in the diagnosis of muscular disorders.

Adult↗
PubMed1983

Biomechanical measurement of spastic plantarflexors.

A study was conducted to determine the feasibility of quantifying spasticity in plantarflexors by measuring the resistance to passive dorsiflexion of the ankle joint at several constant angular speeds. Repeated testing was conducted on normal subjects and spastic patients. Good repeatability was found for both groups and both groups were found to differ significantly from each other with respect to the measurement variable. The method will provide a useful tool for quantifying alterations in plantarflexor spasticity which result from various surgical and non-surgical treatments.

Adolescent↗
PubMed1982

Peroneal-nerve palsy following total knee arthroplasty. A review of The Hospital for Special Surgery experience.

Twenty-three postoperative peroneal-nerve palsies in twenty-two patients were documented in the records of 2626 consecutive knee arthroplasties that were performed at The Hospital for Special Surgery from 1974 through 1980. This is an incidence of 0.87 per cent. The preoperative knee deformities included fourteen flexion contractures, eleven valgus deformities, and five biplane deformities. In five patients a peroneal palsy developed despite a peroneal-nerve release at the time of arthroplasty. Only two patients, who initially had only a motor loss, had a complete clinical recovery. Follow-up ranged from six months to seven years (average 3.1 years). Sensory deficits, initially noted in eighteen patients, had not fully resolved in any patient at the time of writing. Although motor deficits were initially noted in all patients, only 28.6 per cent of them fully resolved. The possible causes of the nerve palsy appeared to be direct traction on the nerve, traction on the surrounding tissues resulting in vascular compromise to the nerve, direct pressure on the nerve from the postoperative dressing, or a combination of these factors. When the palsy is discovered, the suggested treatment is a change to a looser dressing and flexion of the knee. The value of surgical exploration of the nerve in the immediate postoperative period is not known.

Adolescent↗
PubMed1981

Operative treatment of olecranon fractures. Excision or open reduction with internal fixation.

We reviewed the cases of 107 patients who underwent surgical treatment of an isolated fracture of the olecranon. Fifty-three patients were treated by primary excision and fifty-four, by open reduction and internal fixation by various methods. Static and dynamic strength measurements were obtained from the elbow extensors of twenty-nine patients from these two groups. In the over-all series, the ratings for pain, function, range of motion, elbow stability, and incidence of degenerative joint changes were similar for each group. However, thirteen local complications occurred in the fifty-four patients who had open reduction and two, in the fifty-three who had primary excision. Need for removal of the fixation device led to an additional thirteen procedures in the fixation group. Biomechanical testing demonstrated no significant difference in elbow extensor performance for the two groups.

Adult↗
PubMedDate not supplied

Radiologic measurement of superior displacement of the humeral head in the impingement syndrome.

A method for directly measuring the position of the humeral head on the face of the glenoid in different positions of abduction of the arm was developed. We studied three subject groups: 12 patients with normal shoulders (group 1), 15 patients with stage II impingement syndrome (group 2), and 20 patients with rotator cuff tears or stage III impingement (group 3). The study consisted of a series of anteroposterior roentgenograms in the plane of the scapula with the arm in neutral rotation. Roentgenograms were obtained at 20 degrees intervals as the arm was elevated in the plane of the scapula from 0 degree to 120 degrees. Patients held a weight equal to 2 1/2% of body weight in the hand. The parameters measured were excursion of the humeral head on the glenoid face, expressed as the distance that the center of the head lies above or below the center of the glenoid, arm angle, scapulothoracic angle, and glenohumeral angle. For patients with normal shoulders (group 1), there was no significant change in position of the humeral head with arm elevation. In contrast, those with stage II impingement (group 2) had significant (p < 0.05) superior displacement of the center of the humeral head with arm elevation. Patients with rotator cuff tears (group 3) demonstrated a significant rise (p < 0.05) during the first 40 degrees of abduction. The average position of the humeral head in the two pathologic patient groups was superior (p < 0.05) to the average head position in the normal patient group. There was no significant difference in head position between patients with stage II impingement and patients with rotator cuff tear. The ratio of the glenohumeral angle to the scapulothoracic angle during abduction was calculated for our patient groups. In both patient groups, arm abduction had a larger scapulothoracic component than for normal shoulders. The superior migration of the humeral head is a probable result of cuff failure, either partial or complete.

Adult↗
PubMedDate not supplied

Radiographic evaluation of glenohumeral kinematics: a muscle fatigue model.

The purpose of this study was to document the effect of muscle fatigue on glenohumeral kinematics. Twelve male volunteers without shoulder disease and with an average age of 27 years were studied. Glenohumeral anteroposterior radiographs were taken at 45 degrees intervals as the arm was abducted in the plane of the scapula from 0 degree to 135 degrees. This series of radiographs was performed both before and immediately after the subject performed a series of deltoid and rotator cuff fatiguing exercises. The average humeral head position or translation before and after muscle fatigue for each arm angle was compared. For all subjects, before fatigue, the position of the humeral head was below the center of the glenoid for all angles of abduction. There was essentially no change in position of the humeral head in the prefatigue state, as the arm was abducted from 0 degree to 135 degrees with no more than an average 0.3 mm of total humeral head excursion. After fatigue, excursion of the humeral head increased to an average of 2.5 mm between the tested positions. The position of the humeral head with the arm at 0 degree of abduction was lower or had migrated inferiorly compared with the rested state, with an average 1.2 mm significant increase in inferior translation. With the initiation of abduction, the humeral head demonstrated significant superior migration or translation in all positions tested. This result has important implications for conservative treatment of shoulder impingement and underscores the importance of rehabilitation to maximize the endurance and strength of the rotator cuff musculature.

Adult↗
PubMedDate not supplied

Measurement of plantar flexor spasticity during treatment with tone-reducing casts.

The purpose of this study was to examine the hypothesis that treatment with short-leg, tone-reducing casts will alter resistance of the plantar flexors to dynamic and static stretch. The torque resisting passive dorsiflexion was measured at angular velocities of 0, 12, 60, and 120 degrees/s for 16 spastic extremities. The short-term changes in dynamic sensitivity and static sensitivity were not significant. Longer-term wearing resulted in significant decreases in both dynamic sensitivity and static sensitivity. Thus, a change in resistance to stretch did occur with longer-term casting.

Casts, Surgical↗
PubMedDate not supplied

Gait analysis in surgically treated clubfoot.

Clubfoot, a congenital foot abnormality, has been successfully managed with surgical treatment. To assess gait in individuals with surgically treated clubfeet, the patterns of electromyographic activity for the medical gastrocnemius and tibialis anterior muscles and the stride characteristics during gait were measured and compared with normal values. The duration of medial gastrocnemius activity was significantly greater than normal, whereas tibialis anterior activity, stride length, and single limb support times were not different. No correlation was found between the results of the gait analysis and the quality of the surgical result.

Child↗
PubMedDate not supplied

Torque-velocity relationships of the knee extensor and flexor muscles in individuals sustaining injuries of the anterior cruciate ligament.

Muscle deficits in 58 patients with chronic anterior cruciate ligament (ACL) insufficiency were evaluated after completion of a 6 month rehabilitation program. Quadriceps and hamstring torques were measured on a modified Cybex II isokinetic dynamometer. Twenty-nine of our patients were tested just prior to undergoing ACL reconstruction, and patients who were continuing to tolerate their conditions served as controls. For the surgical group, significant quadriceps deficits (P less than 0.01) were found for all speeds and at both the 30 and 60 degrees positions. The nonsurgical group had significant deficits at the 30 degrees position at 180 degrees/sec, and at 60 degrees for the 0 degree/sec and 30 degrees/sec. However, in comparing the two groups no significant differences were noted. Regarding hamstring deficits in the surgical group, significant deficits were seen only at 30 degrees of flexion at 180 degrees/sec. The nonsurgical group had similar deficits. Of interest was the observation that the hamstring:quadriceps (H:Q) ratio was found to be both speed-position dependent. Overall, no correlation was found between the presence of strength deficits following a rehabilitation program and the need for surgery.

Adolescent↗
PubMedDate not supplied

Anteroposterior tibiofemoral displacements during isometric extension efforts. The roles of external load and knee flexion angle.

Rehabilitation of knee extensors is a major consideration in patients with cruciate injuries and repairs. Extension exercises, however, can produce undesirable loads on the injured or replaced anterior cruciate ligament (ACL) resulting in permanent stretch of this restraint. Our study measures the tibiofemoral displacements associated with proximal, middle, and distal locations of the external resisting force and knee flexion angles of 30 degrees, 60 degrees, and 90 degrees. Our results show that tibiofemoral displacements are dependent on both location of the external resisting force and knee flexion angle, with anterior displacements being associated with distal displacement of the resistance pad. The results suggest that patients with ACL injuries or repairs conduct extension exercises with a proximal position of the resistance pad to minimize loads and prevent stretching of this constraint.

Adult↗
PubMedDate not supplied

Torque production in the shoulder of the normal young adult male. The interaction of function, dominance, joint angle, and angular velocity.

Shoulder torque measurements were obtained from 36 normal young adult males during flexion, abduction, internal rotation, and external rotation. Normative, angle-specific torque measurements were determined under isometric conditions and isokinetically at 48 deg/sec. The effects of dominance, angular velocity, and joint position were determined and a method provided for determining the expected maximal torque at a specific speed and position based upon torque measurements from the contralateral shoulder. This method can be used in cases of unilateral shoulder abnormalities to predict normative torque values for the affected side based on torque measurements from the unaffected shoulder.

Adult↗