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Biomedical subjects

C Milgrom

Publications and source records attributed to C Milgrom.

At least 37 records · Page 2Linked to original sources
PubMed1996

The effect of shoe gear on human tibial strains recorded during dynamic loading: a pilot study.

The study was conducted to test the hypothesis that alterations in shoe gear can affect tibial strains in the human during dynamic loading. Rosette strain gauges were mounted on the medial border of the mid-diaphysis in two human subjects with a new strain gauge bonding technique using methyl methacrylate. Strain measurements were made at this site, the most frequent location for stress fractures in the Israeli Army during treadmill walking and free running while wearing various sport shoes (Rockport ProWalkers and New Balance NBX 900) and army boots (light Israeli infantry, double layered sole Israeli infantry, and Zohar infantry boots). Data were analyzed for only one of the subjects because strain gauge bonding was found to be inadequate at the time of surgical removal in the other subject. No single shoe lowered both the principal tibial compression and tensile strains, and the shear strains. The Zohar boot had the lowest principal compression strains during treadmill walking and mobile running, despite its relatively higher weight and sole durometry.

Biomechanical Phenomena↗
PubMed1995

Aging and matrix microdamage accumulation in human compact bone.

Bone matrix microdamage in bone matrix, evidenced as microcracks, occurs consequent to cyclic loading. Microdamage caused by in vivo loading has been described in human rib cortex; however, the existence and extent of microcracks in human long bone cortices are largely unknown. Using histomorphometric methods to examine the incidence and localization of microcracks in human femoral compact bone specimens, we found that the amount of microdamage present in femoral compact bone increases dramatically with increasing age. Least squares regression analysis showed that in males, microcrack density (Cr.De., #/mm2) increases exponentially with age (r2 = 0.70). In females, Cr.De. also increases as an exponential function of increasing age (r2 = 0.79), at a significantly higher rate than in male specimens (p < 0.001). The current studies indicate that with increasing age, bone microdamage accumulates more rapidly than intrinsic processes can effect its repair. A combination of cumulative loading history, focal changes in material properties and alteration in the ability of the tissue to perceive and/or react to microcracks may all play role in this accumulation of bone microdamage with aging. This accumulation of microdamage in bone will contribute to decreased strength and stiffness. In addition, and perhaps most significantly for understanding aging and increased bone fragility, matrix microdamage in composite materials like bone will result in a profoundly reduced resistance to fracture. The importance of this accumulation of matrix microdamage in human bone with increasing age in contributing to the increased fragility of the aging skeleton is discussed.

Adolescent↗
PubMed1995

Bone scintigraphy in the assessment of the hallucal sesamoids.

Bone scintigraphy is frequently used to evaluate suspected hallucal sesamoid pathology. Increased scintigraphic activity of the hallucal sesamoid is assumed to corroborate clinical suspicion of pathology, but the incidence of such increased uptake has not been studied in an asymptomatic population. Using a 0 to 2 bone scintigraphic rating system, 25 of 86 (29%) asymptomatic infantry recruits and 7 of 27 (26%) asymptomatic sedentary adults were found to have grade 1 or grade 2 activity. When using scintigraphy to evaluate hallucal sesamoid pathology, caution should be used in interpreting the meaning of increased scintigraphic activity.

Adolescent↗
PubMed1995

Rotator-cuff changes in asymptomatic adults. The effect of age, hand dominance and gender.

We studied the integrity of the rotator cuff in both dominant and non-dominant shoulders of 90 asymptomatic adults between the ages of 30 and 99 years using ultrasound. The criteria for diagnosis had been validated on unembalmed cadaver specimens. We found no statistically significant difference in the incidence of impingement findings between dominant and non-dominant arms or between genders. The prevalence of partial- or full-thickness tears increased markedly after 50 years of age: these were present in over 50% of dominant shoulders in the seventh decade and in 80% of subjects over 80 years of age. Our results indicate that rotator-cuff lesions are a natural correlate of ageing, and are often present with no clinical symptoms. Treatment should be based on clinical findings and not on the results of imaging.

Adult↗
PubMed1994

Acute postpartum inflammatory sacroiliitis. A report of four cases.

We report four patients with unilateral postpartum sacroiliitis presenting with agonising unilateral pain, an elevated ESR, elevated alkaline phosphatase levels, leucocytosis and positive bone scans. The diagnosis of a non-infectious inflammatory cause was supported by the postpartum onset, the response to non-steroidal anti-inflammatory drugs, negative aspiration cultures in two cases and the lack of changes in the sacroiliac joints on long-term follow-up radiographs.

Acute Disease↗
PubMed1993

Overexertional lumbar and thoracic back pain among recruits: a prospective study of risk factors and treatment regimens.

A total of 395 male infantry recruits were evaluated in a prospective study of possible risk factors for overexertional back pain and the efficacy of drug treatment regimens for this syndrome. Recruits were classified into subgroups of lumbar or thoracic, and paraspinal or spinous process pain. Recruits were divided into three treatment groups: Ibuprofen, Paracetamol, and no drug treatment. Of the recruits, 18% were diagnosed as having overexertional back pain during the course of 14 weeks of training. By multivariate analysis low body mass index was found to be a risk factor for overexertional lumbar pain (p = 0.005) and increased lumbar lordosis a risk factor for overexertional thoracic pain (p = 0.005). Of recruits with overexertional back pain, 65% were asymptomatic by the end of basic training. There was no statistically significant difference between cure rates according to treatment groups.

Acetaminophen↗
PubMed1993

Treatment of overuse patellofemoral pain. Prospective randomized controlled clinical trial in a military setting.

The efficacy of treatment of overuse patellofemoral pain with an elastic knee sleeve with a silicone patellar ring was compared with a simple elastic sleeve and with no treatment in a prospective study of 395 army recruits. During 14 weeks of basic training, 84 knees were diagnosed as having overuse patellofemoral pain. Recruits treated with a simple elastic knee sleeve had a statistically significant better comfort score and more had their pain resolved by the end of training than those treated with elastic knee sleeves with a silicone patellar ring. The mean pain score at the end of training decreased more among recruits who were treated with a simple elastic knee sleeve than among recruits who received no treatment, but this difference was not significant. Among the treatment options tried, the simple elastic knee sleeve was no more effective than no treatment at all, but it was more effective than the more elaborate patellar brace.

Braces↗
PubMed1993

The clinical assessment of femoral stress fractures: a comparison of two methods.

In a prospective study among 667 recruits, the incidence of asymptomatic femoral stress fractures was compared using a new expanded stress fracture clinical examination (SFCA) versus an older stress fracture examination. There was a statistically significant difference (p = 0.0001) between the percentage of femoral stress fractures that were asymptomatic in the group evaluated by SFCA (26%) and those evaluated by the older stress fracture examination (80%). By using the SFCA, many of the femoral stress fractures previously classified as asymptomatic are in fact recognized as symptomatic.

Femoral Fractures↗
PubMed1992

Prevention of overuse injuries of the foot by improved shoe shock attenuation. A randomized prospective study.

In a randomized prospective study among 390 recruits, the hypothesis that improved shoe shock attenuation could lessen the incidence of overuse injuries was tested. During the 14 weeks of training, 90% of the recruits sustained overuse injuries. Recruits training in a modified basketball shoe had a statistically significant lower incidence of metatarsal stress fractures and foot overuse injuries, compared with standard infantry boots, but their overall incidence of overuse injuries was not reduced. The effect of improved shoe shock attenuation was limited to those overuse injuries resulting from vertical impact loads.

Elasticity↗
PubMed1992

A prospective study of the effect of the appropriateness of foot-shoe fit and training shoe type on the incidence of overuse injuries among infantry recruits.

In a prospective study of the effect of the appropriateness of foot-shoe fit and training shoe type on the incidence of overuse injuries among infantry recruits, it was found that three shoe widths for each shoe length size were necessary to adequately accommodate the recruit population's foot anatomy. Recruits compensated for the lack of available shoe widths by choosing larger shoe sizes. However, this compensation did not result in an increase in the incidence of overuse injuries. Recruits who trained in basketball shoes had a lower incidence of overuse injuries of the feet than recruits who trained in infantry boots (p = 0.0001), but the overall incidence of overuse injuries was the same in both groups.

Cumulative Trauma Disorders↗
PubMed1991

Risk factors for lateral ankle sprain: a prospective study among military recruits.

In a prospective study of risk factors for lateral ankle sprain among 390 male Israeli infantry recruits, a 18% incidence of lateral ankle sprains was found in basic training. There was no statistically significant difference in the incidence of lateral ankle sprains between recruits who trained in modified basketball shoes or standard lightweight infantry boots. By multivariate stepwise logistic regression a statistically significant relationship was found between body weight x height (a magnitude which is proportional to the mass moment of inertia of the body around a horizontal axis through the ankle), a previous history of ankle sprain, and the incidence of lateral ankle sprains. Recruits who were taller and heavier and thus had larger mass moments of inertia (P = 0.004), and those with a prior history of ankle sprain (P = 0.01) had higher lateral ankle sprain morbidity in basic training.

Analysis of Variance↗
PubMed1991

Risk factors for stress fractures among Israeli infantry recruits.

In order to answer the question of why the stress fracture morbidity rates among Israeli infantry recruits are so high, we prospectively evaluated 392 infantry recruits for risk factors for stress fractures. Prior to training, each recruit underwent a detailed evaluation. Using multivariate analysis, five risk factors for tibial fractures were identified: shorter tibial length (p less than 0.0001); relatively greater valgus knee alignment (p less than 0.002); right leg dominance (p less than 0.02); external rotation of the hip greater than 65 degrees (p less than 0.02); and training in specific subunits (p less than 0.0002., 0.03). No risk factors for femoral stress fracture were found by multivariate analysis.

Fractures, Stress↗
PubMed1991

Patellofemoral pain caused by overactivity. A prospective study of risk factors in infantry recruits.

A prospective study of 390 infantry recruits revealed that the medial tibial intercondylar distance and that the isometric strength of the quadriceps, tested at 85 degrees of flexion of the knee, had a statistically significant correlation with the incidence of patellofemoral pain caused by overactivity. Increased medial tibial intercondylar distance and increased strength of the quadriceps were therefore deemed to be risk factors for this syndrome.

Anthropometry↗
PubMed1990

Experimental stress fractures of the tibia. Biological and mechanical aetiology in rabbits.

We have shown that stress fractures can be induced in the tibial diaphysis of an animal model by the repeated application of non-traumatic impulsive loads. The right hind limbs of 31 rabbits were loaded for three to nine weeks and changes in the bone were monitored by radiography and bone scintigraphy. The presence of stress fractures was confirmed histologically in some cases. Most animals sustained a stress fracture within six weeks and there was a positive correspondence between scintigraphic change and radiological evidence. Microscopic damage was evident at the sites of positive bone scans. The progression, location, and time of onset of stress fractures in this animal model were similar to those in clinical reports, making the model a useful one for the study of the aetiology of stress fractures.

Animals↗
PubMed1989

Gain in mass density of bone following strenuous physical activity.

A group of 223 military recruits aged 18-21 years underwent strenuous physical training for a period of 14 weeks. The absolute bone density of the distal tibia in both lower limbs was measured before the training period and at its end. The density was determined by the Compton scattering technique, which has been developed in our laboratory; this method provides the bone mass of all bone constituents per unit volume. The distribution curve of the bone density in both tibiae shifted to higher values at the end of the training period. The mean bone density in the right and left tibia increased significantly by 7.5%. This study indicates that following an intensive physical exercise regime, a significant increase in the mass density of bone can be obtained in young adults within a short period.

Adolescent↗