Biomedical subjects

Malcolm H Pope

Publications and source records attributed to Malcolm H Pope.

7 recordsLinked to original sources

PubMed2006

The length of the cervical cord: effects of postural changes in healthy volunteers using positional magnetic resonance imaging.

STUDY DESIGN: The length of the cervical cord in healthy volunteers was measured in the supine and erect position using positional magnetic resonance imaging (MRI). OBJECTIVE: To assess the relationship between the length of the cervical cord and cervical posture in healthy volunteers. SUMMARY OF BACKGROUND DATA: A number of detailed descriptions of the normal morphologic features of the cervical cord have been published. However, to our knowledge, there is no report to compare the relationship between the length of the cervical cord and cervical posture in healthy volunteers using positional MRI. METHODS: This study was performed on 20 healthy volunteers using positional MRI. The subjects were studied in the supine and erect positions. The recumbent series consisted of 3 positions: neutral, flexion, and extension. The erect series consisted of 3 positions: neutral, flexion, and extension. On the midsagittal image, the length of the cervical cord from C1 to C7 was measured at the anterior, middle, and posterior line. The angle of the lower-endplate of C2 and C7 was measured. The results were compared with each series. RESULTS: In the recumbent and erect series, the mean length of the cervical cord in flexion was longer than in neutral and extension at the anterior, middle, and posterior line. There were significant differences between the length of the cervical cord in flexion, neutral, and extension. The mean length of the cervical cord in extension was shorter than in neutral and flexion at the anterior, middle, and posterior line. There were significant differences between length of the cervical cord in extension, neutral, and flexion. CONCLUSIONS: We found posture-dependent differences of the length of the cervical cord in the recumbent and erect series. These results may be important when assessing the dynamic factor in cervical spondylotic myelopathy.

Adult↗

PubMed2006

Biomechanical aspects of the cervical cord: effects of postural changes in healthy volunteers using positional magnetic resonance imaging.

STUDY DESIGN: The area in cross-sectional view of the cervical cord (ACSCC) at each disc levels was measured in supine and erect positions using positional magnetic resonance imaging (pMRI). OBJECTIVES: To assess the relationship between ACSCC and cervical posture in healthy volunteers using pMRI. SUMMARY OF BACKGROUND DATA: There have been few detailed descriptions of the normal morphologic features of the cervical cord. However, there is no report to compare the relationship between ACSCC and cervical posture in healthy volunteers. METHODS: The study was performed on 20 healthy volunteers. The subjects were studied with pMRI in the supine and erect positions. The recumbent series and the erect series consist of 3 positions each: neutral, flexion and extension. On axial images, ACSCC was measured at the C2/3, C3/4, C4/5, C5/6, and C6/7 disc levels. On midsagittal image, the angle of the lower-endplate of C2 and C7 was measured. The results were compared between each series. RESULTS: In the recumbent and erect series, ACSCC was larger in extension than in neutral and flexion at all levels. There were significant differences between ACSCC in extension, neutral and flexion. ACSCC was smaller in flexion than in neutral and extension at all levels. There were significant differences between ACSCC in flexion, neutral and extension. CONCLUSIONS: We found posture-dependent differences of ACSCC in the recumbent and erect series. These results may be valuable for identifying a dynamic factor in patients with cervical spondylotic myelopathy.

Adult↗

PubMed2005

Giovanni Alfonso Borelli--the father of biomechanics.

Giovanni Alfonso Borelli is often described as the father of biomechanics. He was born in Naples in 1608. His De Motu Animalium, published in 1680, extended to biology the rigorous analytical methods developed by Galileo in the field of mechanics. Borelli calculated the forces required for equilibrium in various joints of the human body well before Newton published The Laws of Motion Borelli was the first to understand that the levers of the musculoskeletal system magnify motion rather than force, so that muscles must produce much larger forces than those resisting the motion. Borelli died in Rome on December 31, 1679, but his impressive body of original work helped inspire a great number of future scientists, microscopists, and inventors. The highest honor bestowed by the American Society of Biomechanics is the Giovanni Borelli Award.

Biomechanical Phenomena↗

PubMed2005

Sagittal plane moment arms of the female lumbar region rectus abdominis in an upright neutral torso posture.

BACKGROUND: Prior imaging studies of torso muscle moment arms for use as inputs into biomechanical models have been derived from subjects lying supine. Recent research suggests moment arms of the rectus abdominis are larger when standing versus lying supine. METHODS: Axial MRI images, through and parallel to the intervertebral discs were obtained from five females in a standing upright neutral posture. Digitizing software was utilized to quantify the distance in the sagittal plane between the centroids of the intervertebral disc and the rectus abdominis muscle, and converted to the transverse plane to allow comparisons with studies with subjects in a supine posture. FINDINGS: The mean sagittal plane moment arms in the transverse plane were 9.7, 9.1, 8.5, 8.5 and 9.8 cm at the L(1)/L(2), L(2)/L(3), L(3)/L(4), L(4)/L(5) and L(5)/S(1) intervertebral levels, respectively. Compared with a study on females of a similar age group, the moment arms from this study were larger at each level, increasing from 7.3% larger at L(1)/L(2) to 43.7% larger at L(5)/S(1). INTERPRETATION: Accurate anatomical geometrical representation in biomechanical models is necessary for valid estimates of internal loading. Sagittal plane rectus abdominis moment arms were larger from the upright neutral torso posture in this study compared to studies with subjects lying supine. This suggests the torso internal moment generating capability would be represented differently in biomechanical models that use data from studies where subjects were upright, which is more reflective of the postures biomechanical models are utilized for, than when using anatomical geometry derived from supine postures.

Abdomen↗

PubMed2004

Bernardino Ramazzini: the father of occupational medicine.

Bernardino Ramazzini was born on October 4, 1633, in the small town of Capri located in the duchy of Modula, Italy. He is credited with establishing the field of occupational medicine during his lifetime. His major contributions came after 1682, when Duke Francesco II of Modena assigned him to establish a medical department at the University of Modena. He was installed in the title of professor "Medicinae Theoricae." In 1700, Ramazzini was appointed chair of practical medicine in Padua, Republic of Venice, the premier medical faculty in Italy. In 1700, he wrote the seminal book on occupational diseases and industrial hygiene, De Morbis Artificum Diatriba (Diseases of Workers). Although Ramazzini is perhaps most well known for his work on exposure to toxic materials, he wrote extensively about diseases of the musculoskeletal system. In particular, he warned of the problems of inactivity and poor postures inherent in some jobs.

Cumulative Trauma Disorders↗

PubMed2004

Spine height and disc height changes as the effect of hyperextension using stadiometry and MRI.

STUDY DESIGN: In vivo biomechanical design using stadiometry and MRI to measure the height change due to (hyper)extension. SUMMARY OF BACKGROUND DATA: Spine height is decreased under loads such as lifting, whole body vibration and sitting. Extension including increased lumbar lordosis reduces the load on the spine. METHODS: The aim was to assess the effects of a supine hyperextended posture as a means of restoring the intervertebral disc height after loading and allowing rehydration of the discs. Ten healthy male subjects were tested. A hyperextension intervention was achieved by the means of an inflatable cushion placed under the lumbar spine. The spine height was measured using a stadiometer and MRI was used to assess disc height changes. RESULTS: The spine height gain after 10 minutes of a supine hyperextended posture differed significantly between individuals but everybody gained height. MRI images of the lumbar spine were used to measure the disc height. All but one subjects gained height during the hyperextension. Images of the spine during hyperextended posture showed increased lumbar curve and an increased anterior height of each disc compared with the dimensions of the disc with the spine in neutral posture. CONCLUSIONS: All subjects lost height during sitting. Both methods demonstrated a recovery of height due to hyperextension. Hyperextension could be considered as a prophylaxis against the height loss in occupational loading.

Biomechanical Phenomena↗

PubMed2002

Spine ergonomics.

Occupational low back pain (LBP) is an immense burden for both industry and medicine. Ergonomic and personal risk factors result in LBP, but psychosocial factors can influence LBP disability. Epidemiologic studies clearly indicate the role of mechanical loads on the etiology of occupational LBP. Occupational exposures such as lifting, particularly in awkward postures; heavy lifting; or repetitive lifting are related to LBP. Fixed postures and prolonged seating are also risk factors. LBP is found in both sedentary occupations and in drivers as well as those involved in manual materials handling. Any prolonged posture will lead to static loading of the soft tissues and cause discomfort. Standing and sitting have specific advantages and disadvantages for mobility, exertion of force, energy consumption, circulatory demands, coordination, and motion control. The seated posture leads to inactivity causing an accumulation of metabolites, accelerating disk degeneration and leading to disk herniation. Driver's postures can also lead to musculoskeletal problems. Workers in a driving environment are often subjected to postural stress leading to back, neck, and upper extremity pain. This exacerbates the problems due to the vibration. Prevention is by far the treatment of choice. Improved muscle function can be preventative. Poor coordination and motor control systems are as important as endurance and strength. Fixed postures should be avoided. Seats offering good lumbar support should be used in the office. A suspension seat should be used in vehicles whenever possible. Heavy and awkward lifting should be avoided and lifting aids should be made available. Workers should report LBP as early as possible and seek medical advice if they think occupational exposure is harming them. The combined effects of the medical community, labor, and management are required to cause some impact on this problem.

Comorbidity↗