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The decrease of the cranial rhythmic impulse during maximal physical exertion: an argument for the hypothesis of venomotion?
Journal of Osteopathic Medicine, 2001; 4(1)
© AOMR Inc. 2001
Results. Mean longissimus/iliocostalis fiber angles for upfight standing, hips flexed-spine flexed, and hips flexedspine neutral lordosis were 25.7 degrees, 10.7 degrees and 28.3 degrees, respectively. Conclusions. Anterior shear load on the lumbar spine has been recently shown to be highly related to the risk of reporting a back injury. Bending forward allowing the spine to fully flex changes the line of action of the largest lumbar extensor muscles compromising their role to support anterior shear forces. Relevance. Fiber angles of longissimus thoracis and iliocostalis lumborum were documented with high resolution ultrasound at L3, with the spine in neutral curvature and fully flexed. Full lumbar flexion changes the line of action of these muscle compromising their role to support anterior shear forces on the spine - anterior shear forces have been recently documented to be highly related to the risk of reporting a back injury.
supraspinatus showed the weakest effects (1.3 mm, SD 0.5 mm). Relevance. Strengthening exercises of the deltoid may be useful in the treatment of inferior glenohumeral instability, while the supraspinatus seems to be less important for inferior glenohumeral stability than previously assumed. The effect of strength training and reduced training on rotator cuff musculature McCarrick M J, Kemp JG. Clinical Biomechanics, 2000; 15 Suppl 1:$42-5.
Objective. Elucidate the training frequency required to maintain strength gains acquired via short-term resistance training on the rotator cuff. DESIGN: Twenty-one participants performed 12 wk resistance training followed by 12 wk reduced training. Following the training phase (three rotator-cuff-specific exercises; three sessions/wk), participants were randomly assigned to one of three reduced training groups (2, 1 or 0 session(s)/wk). Methods. Isokinetic testing was done at 0, 6, 12, 18 and 24 wk to obtain mean and peak torque (N m). Testing involved concentric and eccentric actions of internal and external rotation for both shoulders at 60 and 120 degrees/s. Results. Training produced increases in mean and peak torque for all tests but the four of concentric external rotation. A control group performed no training, showing no changes in strength at 0, 6 and 12 wk. Reduced training (2 or 1 session(s)/wk) produced no decreases in peak or mean torque. Detraining (0 session/wk) produced mean torque decreases in four tests, with eccentric strength showing greater losses. Conclusions. A training frequency of 1 session/wk maintains rotator cuff strength gains in previously untrained subjects. Further, eccentric strength may be more susceptible to detraining. Relevance. These findings have direct relevance to functional rehabilitation practices for the rotator cuff. They may aid in resistance training programming for athletes during the off-season or returning from injury, particularly those in overhand sports.
Biomechanics of the cervical spine. I: Normal kinematics B o g d u k N, M e r c e r 2000; 15(9):633-48.
S.
Clinical Biomechanics,
This review constitutes the first of four reviews that systematically address 'contemporary knowledge about the mechanical behavior of the cervical vertebrae and the softtissues of the cervical spine, under normal conditions and under conditions that result in minor or major injuries. This first review considers the normal kinematics of the cervical spine, which predicates the appreciation of the biomechanics of cervical spine injury. It summarizes the cardinal anatomical features of the cervical spine that determine how the cervical vertebrae and their joints behave. The results are collated of multiple studies that have measured the range of motion of individual joints of the cervical spine. However, modern studies are highlighted that reveal that, even under normal conditions, range of motion is not consistent either in time or according to the direction of motion. As well, detailed studies are summarized that reveal the order of movement of individual vertebrae as the cervical spine flexes or extends. The review concludes with an account of the location of instantaneous centres of rotation and their biological basis. Relevance. The fact and precepts covered in this review underlie many observations that are critical to comprehending how the cervical spine behaves under adverse conditions, and how it might be injured. Forthcoming reviews draw on this information to explain how injuries might occur in situations where hitherto it was believed that no injury was possible, or that no evidence of injury could be detected.
Changes in lumbar lordosis modify the role of the extensor muscles McGill SM, Hughson RL, Parks K. Clinical Biomechanics, 2000; 15(10): 777-80.
Study Design. Fiber angles of longissimus thoracis and iliocostalis lumborum at L3 were documented in vivo, using high resolution ultrasound, with the lumbar spine in neutral curve and when fully flexed. Objectives. To evaluate the effect of changes in lumbar curvature on the mechanics of these muscles. Background. Full flexion modifies the failure tolerance of the lumbar spine, determines the load distribution among muscle and passive tissues, and modulates the types of tissue damage that occur. Related to this issue are the possible changes in muscle line of action with full flexion which changes the ability of the spine to support shear loads. Methods. Nine normal men and 5 normal women were scanned in three positions: (1) an upright standing posture; (2) with the hips flexed to approximately 30 degrees and the spine fully flexed; (3) hips flexed but the spine returned to a neutral curvature.
The decrease of the cranial rhythmic impulse during maximal physical exertion: an argument for the hypothesis of venomotion? Farasyn A, Vanderschueren E The Journal of Bodywork and Movement Therapies, 2001; 5:56-59. A new hypothesis for the explanation of the origin of the cranial rhythmic impulse (CRI) is based on the principle of venomotricity. Research on this physiological phenomenon was carded out on bats more than 100 years ago and showed 33
Journal of Osteopathic Medicine, 2001 ; 4(1)
© AOMR Inc. 2001
an automatic rhythm of approximately 10 cycles per min (cpm).
interventions. Common indications for the use of HVLA thrust techniques are 'joint fixation', 'joint locking' and somatic dysfunction but various authors have also described other indications for the therapeutic use of these techniques. Despite a wide range of indications, there has been a decline in the use of HVLA thrust techniques, Concern regarding patient safety and the difficulty associated with gaining mastery of HVLA thrust techniques may be reasons for the decline in their use. While there are potential serious sequelae from the use of HVLA thrust techniques, the risks are low provided patients are thoroughly assessed and treated by appropriately trained practitioners. With increasing evidence that spinal manipulation produces positive patient outcomes for acute low back pain and some categories of neck pain and headache, there is a need to look critically at the indications for the use of HVLA thrust techniques as well as the actual risks and potential benefits of this therapeutic modality.
In this study we will attempt to discover whether a brief physical peak effort has an influence on the CRI. We will assume that there is, in the case of maximal exertion, a brief shift of the CO2/O2volume ratio (RER), which serves as a measure for the energy consumption within the blood vessels. In analogy with this physiological phenomenon we would expect a decrease of the CRI. Three examiners (twice) palpated the cranium and the sacrum for the CRI as well as the vena femoralis for local vasomotion (LVMvf) on a group of healthy subjects (n=15). The examiners changed places during the examination, both before and after the exertion test performed by the subject. The study s h o w e d that the r e p r o d u c i b i l i t y of all measurements is exceptionally high and that there are no significant differences with respect to rhythm between the three measured locations on the body. The physical effort was determined by measuring the supplied physical strain within a certain time. The respiratory ratio (RER) was determined as the CO2/O2volume ratio in the bloodstream. Together with the values of lactic acid concentration these data were used as explanatory variables and compared to the outcome variables, i.e. the CRI of the cranium (CRI cranium), the CRI of the sacrum (CRI sacrum), cardiac pulse (CAP) and local vasomotion of the vena femoralis (LVMvf). It was found that for each of these research variables there was a significantly high difference associated with the exertion test. The experiment demonstrated that 20 rain post-test, a maximal exertion test yields a significant decrease of the three measured rhythms of the CRI cranium, CRI sacrum and LVMvf, with an average reduction of 30%. This suggests that the common decrease probably points to a r e l a t i o n b e t w e e n ' C R I ' and the d e c r e a s e of O2concentration in the bloodstream. The CRI decreases after effort as a result of the simultaneously occurring reduced vasomotricity and does not show a proportional increase due to increased cardiac rhythm. As the three rhythms, CRI cranium, CRI sacrum and LVMvf, which were measured simultaneously, correspond both before and after the exertion test, and since all three rhythms decreased markedly following exertion, it is possible to hypothesize that venous vasomotricity is probably one of the forces behind CRI. Venomotricity is found in all the veins of the body, not only those in the cranium, for example in the vena porta, vena femoralis, vena poplitea, vena saphena magna etc.
Case Report: Resolution of suckling intolerance in a 6month-old chiropractic patient Holtrop DP. Journal of Manipulative and Physiological Therapeutics, 2000; 23:615-618.
Objective: To discuss the management and resolution of suckling intolerance in a 6-month-old infant. Clinical Features: A 6-month-old boy with a 4½-month history of aversion to suckling was evaluated in a chiropractic office. Static and motion palpation and observation detected an abnormal inward dishing at the occipitoparietal junction, as well as upper cervical (C1-C2) asymmetry and fixation. These indicated the presence of cranial and upper cervical subluxations. Intervention and Outcome: The patient was treated 5 times through use of cranial adjusting; 4 of these visits included atlas (C1) adjustment. The suckling intolerance resolved immediately after the first office visit and did not return. Conclusion: It is possible that in the infant, a relationship between mechanical abnormalities of the cervicocranial junction and suckling dysfunction exists; further research in this area could be beneficial. Possible physiological etiologies of painful suckling are presented.
Highlighting of intervertebral m o v e m e n t s and variations of intradiskal pressure during lumbar spine manipulation: A feasibility study Maigne JY, Guillon F. Journal of Manipulative & Physiological Therapeutics, 2000;23:531-5. Objectives: To demonstrate relative movement of the vertebrae and variations in intradiskal pressure during 2 different lumbar spinal manipulations, in flexion or extension, in 2 unembalmed cadavers. Design: A pressure sensor was inserted into the L3-4 disk in cadaver 1 and into the L1-2 to L4-5 disks in cadaver 2. Two adjacent vertebrae (L3 and L4 in cadaver 1, and L4 and L5 in cadaver 2) were each equipped with 2 monoaxial accelerometers to record acceleration in the caudocranial axis and a biaxial accelerometer to record acceleration in the "horizontal" anatomic plane. Setting. Laboratory study. Results. During the thrust, relative intervertebral m o v e m e n t s were
Spinal manipulation: Indications, risks and benefits Gibbons P, Tehan R Journal of Bodywork and Movement Therapies, 2001; 5:110-119. High velocity low amplitude (HVLA) thrust techniques are widely used by many manual medicine disciplines to treat spinal dysfunction. Techniques of this type are associated with an audible release in the form of a pop or cracking sound that is widely accepted to represent cavitation of a spinal zygapophysealjoint. This audible release distinguishes H V L A thrust techniques from other manual medicine 34
© AOMR Inc. 2001
Results. Mean longissimus/iliocostalis fiber angles for upfight standing, hips flexed-spine flexed, and hips flexedspine neutral lordosis were 25.7 degrees, 10.7 degrees and 28.3 degrees, respectively. Conclusions. Anterior shear load on the lumbar spine has been recently shown to be highly related to the risk of reporting a back injury. Bending forward allowing the spine to fully flex changes the line of action of the largest lumbar extensor muscles compromising their role to support anterior shear forces. Relevance. Fiber angles of longissimus thoracis and iliocostalis lumborum were documented with high resolution ultrasound at L3, with the spine in neutral curvature and fully flexed. Full lumbar flexion changes the line of action of these muscle compromising their role to support anterior shear forces on the spine - anterior shear forces have been recently documented to be highly related to the risk of reporting a back injury.
supraspinatus showed the weakest effects (1.3 mm, SD 0.5 mm). Relevance. Strengthening exercises of the deltoid may be useful in the treatment of inferior glenohumeral instability, while the supraspinatus seems to be less important for inferior glenohumeral stability than previously assumed. The effect of strength training and reduced training on rotator cuff musculature McCarrick M J, Kemp JG. Clinical Biomechanics, 2000; 15 Suppl 1:$42-5.
Objective. Elucidate the training frequency required to maintain strength gains acquired via short-term resistance training on the rotator cuff. DESIGN: Twenty-one participants performed 12 wk resistance training followed by 12 wk reduced training. Following the training phase (three rotator-cuff-specific exercises; three sessions/wk), participants were randomly assigned to one of three reduced training groups (2, 1 or 0 session(s)/wk). Methods. Isokinetic testing was done at 0, 6, 12, 18 and 24 wk to obtain mean and peak torque (N m). Testing involved concentric and eccentric actions of internal and external rotation for both shoulders at 60 and 120 degrees/s. Results. Training produced increases in mean and peak torque for all tests but the four of concentric external rotation. A control group performed no training, showing no changes in strength at 0, 6 and 12 wk. Reduced training (2 or 1 session(s)/wk) produced no decreases in peak or mean torque. Detraining (0 session/wk) produced mean torque decreases in four tests, with eccentric strength showing greater losses. Conclusions. A training frequency of 1 session/wk maintains rotator cuff strength gains in previously untrained subjects. Further, eccentric strength may be more susceptible to detraining. Relevance. These findings have direct relevance to functional rehabilitation practices for the rotator cuff. They may aid in resistance training programming for athletes during the off-season or returning from injury, particularly those in overhand sports.
Biomechanics of the cervical spine. I: Normal kinematics B o g d u k N, M e r c e r 2000; 15(9):633-48.
S.
Clinical Biomechanics,
This review constitutes the first of four reviews that systematically address 'contemporary knowledge about the mechanical behavior of the cervical vertebrae and the softtissues of the cervical spine, under normal conditions and under conditions that result in minor or major injuries. This first review considers the normal kinematics of the cervical spine, which predicates the appreciation of the biomechanics of cervical spine injury. It summarizes the cardinal anatomical features of the cervical spine that determine how the cervical vertebrae and their joints behave. The results are collated of multiple studies that have measured the range of motion of individual joints of the cervical spine. However, modern studies are highlighted that reveal that, even under normal conditions, range of motion is not consistent either in time or according to the direction of motion. As well, detailed studies are summarized that reveal the order of movement of individual vertebrae as the cervical spine flexes or extends. The review concludes with an account of the location of instantaneous centres of rotation and their biological basis. Relevance. The fact and precepts covered in this review underlie many observations that are critical to comprehending how the cervical spine behaves under adverse conditions, and how it might be injured. Forthcoming reviews draw on this information to explain how injuries might occur in situations where hitherto it was believed that no injury was possible, or that no evidence of injury could be detected.
Changes in lumbar lordosis modify the role of the extensor muscles McGill SM, Hughson RL, Parks K. Clinical Biomechanics, 2000; 15(10): 777-80.
Study Design. Fiber angles of longissimus thoracis and iliocostalis lumborum at L3 were documented in vivo, using high resolution ultrasound, with the lumbar spine in neutral curve and when fully flexed. Objectives. To evaluate the effect of changes in lumbar curvature on the mechanics of these muscles. Background. Full flexion modifies the failure tolerance of the lumbar spine, determines the load distribution among muscle and passive tissues, and modulates the types of tissue damage that occur. Related to this issue are the possible changes in muscle line of action with full flexion which changes the ability of the spine to support shear loads. Methods. Nine normal men and 5 normal women were scanned in three positions: (1) an upright standing posture; (2) with the hips flexed to approximately 30 degrees and the spine fully flexed; (3) hips flexed but the spine returned to a neutral curvature.
The decrease of the cranial rhythmic impulse during maximal physical exertion: an argument for the hypothesis of venomotion? Farasyn A, Vanderschueren E The Journal of Bodywork and Movement Therapies, 2001; 5:56-59. A new hypothesis for the explanation of the origin of the cranial rhythmic impulse (CRI) is based on the principle of venomotricity. Research on this physiological phenomenon was carded out on bats more than 100 years ago and showed 33
Journal of Osteopathic Medicine, 2001 ; 4(1)
© AOMR Inc. 2001
an automatic rhythm of approximately 10 cycles per min (cpm).
interventions. Common indications for the use of HVLA thrust techniques are 'joint fixation', 'joint locking' and somatic dysfunction but various authors have also described other indications for the therapeutic use of these techniques. Despite a wide range of indications, there has been a decline in the use of HVLA thrust techniques, Concern regarding patient safety and the difficulty associated with gaining mastery of HVLA thrust techniques may be reasons for the decline in their use. While there are potential serious sequelae from the use of HVLA thrust techniques, the risks are low provided patients are thoroughly assessed and treated by appropriately trained practitioners. With increasing evidence that spinal manipulation produces positive patient outcomes for acute low back pain and some categories of neck pain and headache, there is a need to look critically at the indications for the use of HVLA thrust techniques as well as the actual risks and potential benefits of this therapeutic modality.
In this study we will attempt to discover whether a brief physical peak effort has an influence on the CRI. We will assume that there is, in the case of maximal exertion, a brief shift of the CO2/O2volume ratio (RER), which serves as a measure for the energy consumption within the blood vessels. In analogy with this physiological phenomenon we would expect a decrease of the CRI. Three examiners (twice) palpated the cranium and the sacrum for the CRI as well as the vena femoralis for local vasomotion (LVMvf) on a group of healthy subjects (n=15). The examiners changed places during the examination, both before and after the exertion test performed by the subject. The study s h o w e d that the r e p r o d u c i b i l i t y of all measurements is exceptionally high and that there are no significant differences with respect to rhythm between the three measured locations on the body. The physical effort was determined by measuring the supplied physical strain within a certain time. The respiratory ratio (RER) was determined as the CO2/O2volume ratio in the bloodstream. Together with the values of lactic acid concentration these data were used as explanatory variables and compared to the outcome variables, i.e. the CRI of the cranium (CRI cranium), the CRI of the sacrum (CRI sacrum), cardiac pulse (CAP) and local vasomotion of the vena femoralis (LVMvf). It was found that for each of these research variables there was a significantly high difference associated with the exertion test. The experiment demonstrated that 20 rain post-test, a maximal exertion test yields a significant decrease of the three measured rhythms of the CRI cranium, CRI sacrum and LVMvf, with an average reduction of 30%. This suggests that the common decrease probably points to a r e l a t i o n b e t w e e n ' C R I ' and the d e c r e a s e of O2concentration in the bloodstream. The CRI decreases after effort as a result of the simultaneously occurring reduced vasomotricity and does not show a proportional increase due to increased cardiac rhythm. As the three rhythms, CRI cranium, CRI sacrum and LVMvf, which were measured simultaneously, correspond both before and after the exertion test, and since all three rhythms decreased markedly following exertion, it is possible to hypothesize that venous vasomotricity is probably one of the forces behind CRI. Venomotricity is found in all the veins of the body, not only those in the cranium, for example in the vena porta, vena femoralis, vena poplitea, vena saphena magna etc.
Case Report: Resolution of suckling intolerance in a 6month-old chiropractic patient Holtrop DP. Journal of Manipulative and Physiological Therapeutics, 2000; 23:615-618.
Objective: To discuss the management and resolution of suckling intolerance in a 6-month-old infant. Clinical Features: A 6-month-old boy with a 4½-month history of aversion to suckling was evaluated in a chiropractic office. Static and motion palpation and observation detected an abnormal inward dishing at the occipitoparietal junction, as well as upper cervical (C1-C2) asymmetry and fixation. These indicated the presence of cranial and upper cervical subluxations. Intervention and Outcome: The patient was treated 5 times through use of cranial adjusting; 4 of these visits included atlas (C1) adjustment. The suckling intolerance resolved immediately after the first office visit and did not return. Conclusion: It is possible that in the infant, a relationship between mechanical abnormalities of the cervicocranial junction and suckling dysfunction exists; further research in this area could be beneficial. Possible physiological etiologies of painful suckling are presented.
Highlighting of intervertebral m o v e m e n t s and variations of intradiskal pressure during lumbar spine manipulation: A feasibility study Maigne JY, Guillon F. Journal of Manipulative & Physiological Therapeutics, 2000;23:531-5. Objectives: To demonstrate relative movement of the vertebrae and variations in intradiskal pressure during 2 different lumbar spinal manipulations, in flexion or extension, in 2 unembalmed cadavers. Design: A pressure sensor was inserted into the L3-4 disk in cadaver 1 and into the L1-2 to L4-5 disks in cadaver 2. Two adjacent vertebrae (L3 and L4 in cadaver 1, and L4 and L5 in cadaver 2) were each equipped with 2 monoaxial accelerometers to record acceleration in the caudocranial axis and a biaxial accelerometer to record acceleration in the "horizontal" anatomic plane. Setting. Laboratory study. Results. During the thrust, relative intervertebral m o v e m e n t s were
Spinal manipulation: Indications, risks and benefits Gibbons P, Tehan R Journal of Bodywork and Movement Therapies, 2001; 5:110-119. High velocity low amplitude (HVLA) thrust techniques are widely used by many manual medicine disciplines to treat spinal dysfunction. Techniques of this type are associated with an audible release in the form of a pop or cracking sound that is widely accepted to represent cavitation of a spinal zygapophysealjoint. This audible release distinguishes H V L A thrust techniques from other manual medicine 34