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Biomedical subjects

J K Gronley

Publications and source records attributed to J K Gronley.

7 recordsLinked to original sources
PubMed1991

Valgus deformities of the feet and characteristics of gait in patients who have rheumatoid arthritis.

To investigate the cause of valgus deformity of the hindfoot in patients who have rheumatoid arthritis and to characterize the effects of the deformity on gait, two groups of patients were evaluated clinically, radiographically, and with gait analysis in the laboratory. Group 1 consisted of seven patients who had seropositive rheumatoid arthritis and normal alignment of the feet and Group 2, of ten patients who had rheumatoid arthritis and valgus deformity of the hindfoot. In Group 2, the disease was of longer duration and the feet were more painful than in Group 1. There was no evidence of muscular imbalance, equinus contracture, valgus deformity of the tibiotalar joint, or isolated deficiency of the tibialis posterior (such as weakness, tenosynovitis, or rupture of the tendon) that could have contributed to the development of the valgus deformity. In the patients who had valgus deformity, quantitated electromyography demonstrated that the intensity and duration of activity of the tibialis posterior was significantly increased, apparently in an effort to support the collapsing longitudinal arch of the foot. Gait studies revealed decreases in velocity, stride length, and single-limb-support time, as well as delayed heel-rise in both groups, but the decreases were more marked in the patients who had valgus deformity. The results of this study suggest that valgus deformity of the hindfoot in rheumatoid patients results from exaggerated pronation forces on the weakened and inflamed subtalar joint. These forces are caused by alterations in gait secondary to symmetrical muscular weakness and the effort of the patient to minimize pain in the feet. Radiographs also suggested an association between the valgus deformity of the feet and valgus deformity of the knees in patients who have rheumatoid arthritis.

Adult↗
PubMed1989

Pelvic exercise and gait in hemiplegia.

The purpose of this study was to describe and compare the gait of 20 patients with hemiplegia secondary to cerebrovascular accident (CVA) before and after a treatment regimen of resisted pelvic motions. Ten women and 10 men were studied, with a mean age of 48 years and a mean duration post-CVA of two months. Nine subjects (45%) were right hemiplegic, and 11 subjects (55%) were left hemiplegic. Treatment consisted of four sets of five repetitions each of manually resisted pelvic anterior-elevation and posterior-depression movements on the involved side. An insole footswitch system, knee electrogoniometer, and force walking aid were used in gait analysis performed before treatment, immediately after treatment (posttest 1), and 30 minutes after treatment (posttest 2). Results showed significant overall improvement in gait in posttest 1 (p less than .005) compared with the pretest. This improvement, however, was not maintained in posttest 2. Ten patients improved overall in posttest 1; only 4 patients also showed improvement in posttest 2. The major improvements seen immediately after treatment were observed in stance stability and limb advancement in the involved limb. More research is needed to identify an optimum treatment with carry-over using this technique.

Adult↗
PubMed1988

The postpolio syndrome. An overuse phenomenon.

Persons with good recovery of function following their initial poliomyelitis are now, more than 30 years later, experiencing new weakness, fatigue, and muscle pain. The likelihood of muscle overuse being the cause of this late functional loss was investigated by dynamic electromyography (EMG) and foot-switch stride analysis in 34 symptomatic patients. Manual testing grouped the muscles, with strong (S) encompassing Grades Good (G) and Normal (N) while weak (W) included Fair plus (F+) to zero (0). After testing quadriceps and calf strength, the patients fell into one of four classes: strong quadriceps and calf (SQ/SC), strong quadriceps and weak calf (SQ/WC), weak quadriceps and strong calf (WQ/SC), or combined weak quadriceps and calf (WQ/WC). Quantified EMG (normalized by the manual muscle test EMG) defined the mean duration and intensity of the quadriceps, soleus, lower gluteus maximus, and long head of the biceps femoris during walking. Overuse was defined as values greater than the laboratory normal (mean + 1 SD). Each muscle exhibited instances of overuse, normalcy, and sparing. The biceps femoris was the only muscle with dominant overuse (82%). Quadriceps overuse was next in frequency (53%). Soleus activity infrequently exceeded normal function (34%), but this still represented more than twice the intensity and duration of the other muscles. Gluteus maximus action was also seldom excessive (34%). The patients averaged two muscles with excessive use during walking. Gait velocity of the SQ/SC strong group was highest (71% of normal) while the three categories that included weak muscles had walking speeds in the range of 50% of normal. The finding of muscle overuse during a single free-speed walking test that does not attain normal velocity supports the concept of muscle overuse being the cause of the patient's dysfunction.

Adult↗
PubMed1984

Gait analysis techniques. Rancho Los Amigos Hospital gait laboratory.

In the gait laboratory at Rancho Los Amigos Hospital, the emphasis is on patient testing to identify functional problems and determine the effectiveness of treatment programs. Footswitch stride analysis, dynamic EMG, energy-cost measurements, force plate, and instrumented motion analysis are the techniques most often used. Stride data define the temporal and distance factors of gait. We use this information to classify the patient's ability to walk and measure response to treatment programs. Inappropriate muscle action in the patient disabled by an upper motor neuron lesion is identified with dynamic EMG. Intramuscular wire electrodes are used to differentiate the action of adjacent muscles. We use the information to localize the source of abnormal function so that selection of treatment procedures is more precise. Force and motion data aid in determining the functional requirement and the muscular response necessary to meet the demand. Determining the optimum mode of locomotion and developing criteria for program planning have become more realistic with the aid of energy-cost measurements. Microprocessors and personal computer systems have made compact and reliable single-concept instrumentation available for basic gait analysis in the standard clinical environment at a modest cost. The more elaborate composite systems, however, still require custom instrumentation and engineering support.

Adult↗
PubMed1983

Timing and relative intensity of hip extensor and abductor muscle action during level and stair ambulation. An EMG study.

The timing and relative intensity of electromyographic activity of hip abductor and extensor muscles were recorded during free and fast velocity walking and during ascent and descent of stairs. Eleven healthy subjects were tested using fine wire electrodes to record the electromyographic activity. Data were quantified by normalizing all electromyographic activity during gait with electromyographic activity occurring during a sustained maximum isometric effort resisted either manually or with a dynamometer. The results indicated that the hip extensor muscles had different phasic patterns and moments of peak activity. During level walking, the semimembranosus and long head of the biceps femoris muscles displayed the greatest swing phase activity (beginning in mid-swing). The adductor magnus muscle followed with its onset in terminal swing. Both this muscle and the gluteus maximus were the principal hip extensors active during the loading response. For ascending stairs, the lower portion of the gluteus maximus muscle proved to be the main hip extensor during the loading response and mid-stance. The findings also showed that the upper portion of the gluteus maximus muscle functioned more like the gluteus medius muscle than the lower portion of the gluteus maximus muscle during both level and stair walking.

Adult↗
PubMed1981

Rocker shoe as walking aid in multiple sclerosis.

Evaluation of rocker shoes as a walking aid for multiple sclerosis patients included a mechanical analysis of the shoes, establishment of clinical criteria for appropriate patient selection, and laboratory gait measurements of patients with and without rocker shoes. Patient fitting demonstrated that the most significant measurement, the roll point, must be about 2cm proximal to the 1st metatarsal head. A snug fit as well as the addition of a heel strap was required to hold the shoe on the foot so its mechanical assistance was consistent. Rocker shoes were effective only in patients who still retained the ability to walk independently; retention of adequate hip and calf strength proved critical. Basic gait deficit was plantar flexion less than 15 degree while standing, leading to knee hypertension and forward trunk leaning, inadequate knee flexion and toe drag in swing, general awkwardness and fatigue. Gait improvement with the rocker shoes varied with clinical classification. Normal velocity and stride characteristic in rocker shoes were accompanied by a marked decrease in net energy cost. A mean saving of 150% of normal energy was gained with rocker shoes.

Adult↗