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PubMedDate not supplied

Experimental study on external tibial rotation of the knee.

Using biplanar roentgenographic photogrammetry, we investigated posterolateral rotatory instability of the knee joint both before and after sectioning of posterolateral structures, the posterior cruciate ligament, and the lateral collateral ligament. Fifteen fresh-frozen cadaveric knees were used. Compared with the intact state, sectioning of the posterior cruciate ligament alone did not increase the amount of external tibial rotation, but the axis of external tibial rotation shifted when the anterolateral bundle of the posterior cruciate ligament was cut. When the posterior cruciate ligament was cut after sectioning of the posterolateral structures and the lateral collateral ligament, external tibial rotation increased and the axis of external rotation shifted. The results demonstrated that sectioning of the anterolateral bundle of the posterior cruciate ligament is associated with a change in the location of the axis of tibial rotation. Therefore an isolated posterior cruciate ligament injury can alter the kinematics of the knee joint by changing the axis of external tibial rotation. The present results also demonstrate that the posterior cruciate ligament serves as a kind of secondary restraint to posterolateral rotatory instability in knees with injured posterolateral structures. Helical motion analysis using biplanar roentgenographic photogrammetry is a useful method for evaluating knee kinematics.

Aged↗
PubMedDate not supplied

Effects of Theraband and lightweight dumbbell training on shoulder rotation torque and serve performance in college tennis players.

The purpose of this study was to determine whether a 4-week isotonic resistance training program using Theraband elastic tubing and lightweight dumbbells would significantly increase concentric shoulder rotator strength or velocity of serve or both in a group of elite-level tennis players. Twenty-two male and female varsity college tennis players were randomly assigned to control or 4-week training groups. Subjects were pre- and posttested in concentric internal and external rotation torque using an isokinetic dynamometer. Functional performance was assessed before and after training by recording the peak and average velocities of eight maximal serves. The experimental group exhibited significant gains in internal rotation torque at both slow (120 deg/sec) and fast speeds (300 deg/sec) for total work and in peak torque to body weight ratio and torque acceleration energy at the fast speed. This group also exhibited significant gains in external rotation torque for the same parameters at fast speed. Regarding speed to serve, the experimental group exhibited significantly greater increase in peak speed (+6.0% compared with -1.8%) and average speed (+7.9% compared with -2.3%) compared with the control group. Men exhibited greater internal and external rotation torque on all parameters and in peak and mean speed of serve on both evaluations. Men also exhibited greater imbalance in external to internal rotation torque ratios. In conclusion, resistance training using Theraband tubing and lightweight dumbbells may have beneficial effects on strength and functional performance in college-level tennis players.

Acceleration↗
PubMed2006

Variation of the distal metatarsal articular angle with axial rotation and inclination of the first metatarsal.

BACKGROUND: The distal metatarsal articular angle (DMAA) is a radiographic measure of the orientation of the first metatarsal articular surface. There is debate with regards to the accuracy, reproducibility, and validity of measurement of the DMAA in the literature. This study aimed to test the validity of the measurement of the DMAA from standard radiographs, to explore the trigonometric relationship of the first metatarsal rotation and the DMAA, and to assess interobserver reliability. METHODS: Thirty-four separate dry cadaver first metatarsal bones were mounted onto a customized light-box-protractor, allowing controlled incremental changes in rotation and inclination. A series of 39 digital photographs were taken of each metatarsal in 5-degree increments of rotation between 30 degrees supination and 30 degrees pronation at 10, 20 and 30 degrees of inclination. Three reviewers performed blinded DMAA measurements from each photographic image; the data were collated for statistical analysis. The data were analysed using a mixed effects linear model comparing the DMAA with rotation of the first metatarsal. RESULTS: A strong statistically significant trend of increasing score with increasing pronation of the metatarsal was observed, the relationship was approximately linear. There was a strong effect of inclination, but the strength of this varied with rotation and was amplified at higher inclinations. Interobserver error was noted in line with other studies, but even allowing for this interobserver error, the linear relationship was maintained. CONCLUSIONS: This study showed that the DMAA varies significantly in a linear pattern with axial rotation of the first metatarsal. Inclination of the first metatarsal also affects the magnitude of the angle. This study does not refute the DMAA as an entity but does confirm the inaccuracy of extrapolating the DMAA from plain anteroposterior radiographs.

Cadaver↗
PubMed1997

Hallucal rotation: a method of measurement and relationship to bunion deformity.

A method for measuring hallucal rotation or weightbearing tangential radiographs is described. Under controlled conditions using cadaver specimens, 10 degree changes in hallucal rotation were associated with a mean change in radiographically measured rotation of 10.6 degrees (S.D. = 2.3 degrees). A clinical study of 30 control patients and 39 patients presenting with a chief complaint of a bunion deformity was undertaken to assess the reliability of the measurement method. The overall reliability was high for both groups (r = 0.98). A significant difference was found between mean values for hallucal rotation in the two groups (P < 0.005). There is a modest association between increasing valgus deviation and increasing rotation of the hallux (r = 0.43, P < 0.01). This study suggests that bunion deformities involve variable degrees of axial and coronal plane rotations of the first metatarsophalangeal joint and that the concept of a planar "hallux valgus" deformity may insufficiently describe this three-dimensional clinical condition.

Cadaver↗
PubMed2003

Prolonged optokinetic stimulation generates podokinetic after rotation.

Previous studies showed that after prolonged stepping in place on the center of a rotating platform blindfolded subjects could no longer step in place on a firm floor. Instead, they invariably rotated themselves relative to space without perceiving their rotation, a phenomenon termed podokinetic after-rotation (PKAR). We speculated that prolonged optokinetic stimulation (OK) alone may generate similar PKAR. The purpose of this study was to evaluate the effects of prolonged OK on podokinetic (PK) responses. Ten healthy subjects participated in the study. After a control stepping test, they were seated in a circular closed cage and randomly (right or left) exposed to an OK (45 degrees /s) covering the whole visual field for 30 min. After this procedure, blindfolded subjects attempted to step in place on the stationary floor for 30 min. When trying to do so, all subjects turned relative to space without any perception of rotation. The direction of this optokinetically after-rotation (oPKAR) was opposite of that of the direction of OK. Mean peak velocity of oPKAR was 7.8 +/- 4.1 degrees /s, and it was reached after approximately 6 min of stepping. After that, there was a progressive velocity decay, which exhibited a discharging time constant on the order of 42 min toward a final positive asymptote of 3.1 degrees /s. We conclude that OK alone causes oPKAR. Long-term OK probably charges a storage element for podomotor activity with a relatively prolonged time constant. This novel form of neural interaction and adaptive plasticity may have significant implications for the treatment of vestibular and parietal lobe disorders.

Adaptation, Ocular↗
PubMed1978

The involvement of catecholamine in scopolamine-induced locomotor activation and rotational behaviour in mice.

Scopolamine-induced locomotor activation was studied in comparison with the responses to apomorphine and methamphetamine in mice. The responses to scopolamine and methamphetamine were markedly depressed by the pretreatment with the catecholamine synthesis inhibitor, alpha-methyl-p-tyrosine, while the activation response to apomorphine was not affected. p-Chlorophenylalanine did not affect the response to scopolamine. Phenoxybenzamine reduced the responses to scopolamine and methamphetamine, but did not affect the apomorphine response. Propranolol did not affect the responses to the three agonists, scopolamine, apomorphine and methamphetamine. Antipsychotic drugs haloperidol and pimozide reduced the responses to the three agonists. Haloperidol was especially effective in this regard. These results suggest the involvement of catecholamine in the locomotor activation produced by scopolamine. In the rotational behaviour model which is sensitive to dopamine receptor stimulating agents, effects of the three agonists were studied. Scopolamine produced the ipsilateral rotation in mice with unilateral striatal 6-hydroxydopamine-induced lesions. Methamphetamine induced the ipsilateral rotation, while apomorphine produced the contralateral rotation. The rotations induced by three agaonists were suppressed by pimozide. The results indicate the participation of dopamine in the scopolamine-induced rotational behaviour in mice.

Animals↗
PubMed2003

The relationship between the strength of supination of the forearm and rotation of the shoulder.

In children with obstetric brachial plexus palsy (OBPP) who develop an internal rotation deformity of the shoulder, release of subscapularis improves the range of external rotation of the shoulder and the strength of supination of the forearm. We studied the strength of supination in 35 healthy adult volunteers at 45 degrees of both internal and external rotation. The mean and maximum torques were greater in external than internal rotation by 8.7% and 7.5%, respectively. This was highly significant (p < 0.0001). The increased strength of supination in external rotation is probably because the maximum power of biceps, particularly the long head, may be exerted in this position. In children the difference may be even greater due to anatomical differences causing the dramatic increases in the strength of supination after surgery for OBPP. In adults our findings suggest that the supination exercises which are undertaken after injury or surgery to the forearm or wrist should be performed in external rotation.

Adult↗
PubMed2004

Rotation of the spinal cord in idiopathic scoliosis.

We undertook a radiographic analysis with pre-operative computed tomographic myelography in 78 patients with idiopathic scoliosis in order to analyse rotation of the spinal cord and to investigate its clinical significance. The angle of rotation of the cord had a statistically significant relationship to both that of the apical vertebra and the size of the primary curve. The relationship between the rotation of the cord and that of the apical vertebra was divided into three types. The cord rotated in the same direction as the apical vertebra in 55 patients and rotated in the opposite direction in the remaining 23 patients. In the first group, the angle of rotation of the cord was more than that of the vertebra in six patients, but less than it in 49 patients. These results suggest that the neuraxis in idiopathic scoliosis may be under tension in the axial dimension.

Adolescent↗
PubMed1997

Use of four mirrors to rotate linear polarization but preserve input-output collinearity. II.

We report on the design, construction, and testing of a four-mirror reflective polarization rotator, proposed by Smith and Koch [J. Opt. Soc. Am. A 13, 2102 (1996)], that rotates by an angle phi the input linear polarization while preserving the input-output beam collinearity. We correct errors in the previous work that led to an incorrect design for a phi = pi/2 rotator. This type of pure rotator is simple and inexpensive, and it is a direct application of the concept of the nonadiabatic geometric phase to polarization rotation. We also present measurements of the polarization rotation for the case of three metallic mirrors with antiparallel input and output beams, a test of geometric phase in polarization optics not done before.

Light↗
PubMed2004

Difference in isokinetic torque acceleration energy of the rotator cuff: competitive male pitchers versus male nonathletes.

Rotator cuff function is critical to the overhead athlete. Rotator cuff power is felt to be important in the overhead athlete during the throwing motion. Little research exists regarding torque acceleration energy (TAE) in overhead athletes. Twenty-five males were divided into 2 groups consisting of overhead athletes (pitchers) (n = 12) and nonoverhead athletes (controls) (n = 13). All participants were given a concentric velocity spectrum isokinetic test at speeds of 60 degrees (1.05 r), 180 degrees (3.16 r), and 300 degrees.s(-1) (5.26 r) to both the dominant and nondominant shoulder internal and external rotators. Significant differences were found for all internal rotator TAE scores (p = 0.000-0.016), at each of the 3 velocities, when comparing dominant to nondominant arms of both overhead athletes and nonoverhead athletes. Only 60 degrees.s(-1) (1.05 r) was found to be different during external rotation TAE testing of the overhead athletes (p = 0.027) but was not found in the control subjects. Post hoc analysis revealed no differences between dominant or nondominant TAE scores when comparisons were made between overhead athletes and controls. Results may reveal that power of the rotator cuff muscles may not be a critical component of the overhead throwing motion.

Adolescent↗
PubMed2003

Rotational stability of a modified step-cut for use in intercalary allografts.

BACKGROUND: Intercalary allografts are used for the reconstruction of major skeletal defects. Step-cuts help to provide rotational stability when intramedullary fixation is used. A modified step-cut is proposed to reduce rotation at the interface. This study compares the rotational stability of conventional and modified step-cuts. METHODS: In Phase I, seven pairs of human cadaveric femora were divided into a conventional step-cut group (left femora) and a modified step-cut group (right femora). All femora were cut transversely at the mid-diaphysis. In the conventional group, a 1-cm step-cut was created in the exact midsagittal plane in both the proximal and distal segments. In the modified group, a 1-cm step-cut was created in the parasagittal plane, leaving 2 mm of additional bone on both the proximal and the distal fragment. Phase II was identical except that in the modified step-cut group only 1 mm of additional bone was left. Smooth femoral nails were then placed after standard reaming. Specimens were tested by fixing the proximal segment and applying +/-2 N-m (17.7 in-lb) of torque to the distal segments with ten oscillation cycles. Maximum rotation was measured. The data were analyzed with the paired Student t test. RESULTS: The average rotation in Phase I was 23.3 degrees for the conventional step-cut group and 3.0 degrees for the 2-mm modified step-cut group; the difference was significant (p < 0.001). Four femora sustained an incomplete fracture during nail insertion. The average rotation in Phase II was 20.6 degrees for the conventional step-cut group and 0.5 degrees for the 1-mm modified step-cut group without any fractures; the difference was significant (p < 0.001). CONCLUSIONS: Step-cut modification that leaves more bone in the sagittal plane provides rigid fixation and significantly more stability than the conventional step-cut technique.

Biomechanical Phenomena↗
PubMed2005

Vestibulo-cardiorespiratory responses at the onset of chair rotation in endurance runners.

Stimulation of the vestibular system has been reported to elicit ventilatory and circulatory changes in humans. The purpose of this study was to clarify the characteristics of vestibular-mediated ventilatory and circulatory responses in male endurance runners at the onset of passive chair rotation, which selectively stimulates the semicircular canals. Fourteen runners and 14 male untrained subjects participated. The vestibular stimulus test, which consists of 180 degrees chair rotations (left or right half-turns on an earth-vertical axis) for a duration of 2 s, was carried out on each subject. Inspiratory minute ventilation, tidal volume, respiratory frequency, heart rate, and blood pressure were measured by breath-by-breath and beat-to-beat techniques before, during, and after the chair rotation for a total of 60 s. It was found in this study that (i) the relative change of minute ventilation response in the endurance runners was significantly (P < 0.05) greater than in the untrained subjects during and after the rotation, and that (ii) no significant group differences were observed in heart rate and mean blood pressure responses during and after the rotation. In conclusion, vestibular-mediated ventilatory response, but not circulatory response, at the onset of the chair rotation in the endurance runners was significantly greater than that in the untrained subjects. The results from the present study suggest that an increase in vestibulo-ventilatory response would be attributed to an adaptation to long-term endurance training.

Adaptation, Physiological↗
PubMed2005

[Kinematic analysis of limitation of mouth opening of temporomandibular disorders by rotation and translation of the condyle].

PURPOSE: The purpose of this study was to determine whether rotation and translation of the condyle were useful parameters for identifying causes of limitation of mouth opening in patients with temporomandibular disorders (TMD). METHODS: In 7 healthy volunteers and 55 patients with TMD, rotation and translation of the condyle were measured using a 6 degree-of-freedom jaw movement tracking device. Patients were divided into two groups: those who could open their mouth 40 mm or greater, and those who could not open their mouth 40 mm. In each group, the relationship of rotation and translation of the condyle to maximum mouth opening, condition of the articular disc, and pain was determined. RESULTS: Both correlations between maximum mouth opening and rotation and translation of the condyle were strong, especially the former correlation. There was no marked difference in the distribution of range of mouth opening, and rotation and translation of the condyle with respect to condition of the artticular disc. Muscle pain was associated with reduced mouth opening. Even in patients without limited mouth opening, their range of mouth opening was actually reduced when they had muscle pain. Among the patients with limited mouth opening, joint pain correlated to limited translation of the condyle. However, in patients with Wo-Wo condition of articular disc, their translation of the condyle was not limited even with joint pain, but it was limited with muscle pain. CONCLUSIONS: Rotation of the condyle indicated strong correlation with muscle pain, and so is a useful parameter for estimating treatment methods by a surgical approach. On the other hand, translation of the condyle showed variations in correspondence with combinations of several factors such as opening limitation, condition of the articular disc, and pain.

Biomechanical Phenomena↗
PubMed2001

Effects of retention intervals on the magnitude of optokinetic rotation-induced taste aversions.

This study investigated the effects of different retention intervals on the magnitude of optokinetic rotation-induced conditioned taste aversions in humans. Two experiments were conducted. In Exp. 1, 20 subjects were divided into two groups, a CS-UCS group in which drinking soybean milk was paired with optokinetic rotation-induced gastric illness and a CS-Only group in which drinking soybean milk was not paired with optokinetic rotation. Analysis indicated that two days after pairing soybean milk drinking with optokinetic rotation, the subjects in the CS-UCS group had significantly reduced palatability ratings of soybean milk and lower consumption of soybean milk than those in the CS-Only group. In Exp. 2, 40 subjects were divided into four CS-UCS groups with 1-day, 3-day, 5 day, and 10-day retention intervals between the session of pairing soybean milk with optokinetic rotation and the session of retasting soybean milk. Analysis yielded no significant differences among four groups on palatability of soybean milk and consumption of soybean milk in the retasting session. It is concluded that optokinetic rotation is an effective unconditioned stimulus for conditioned taste aversions formation and that the aversion has a retention period of at least 10 days.

Avoidance Learning↗
PubMed1995

A comparison of cervical rotation in age-matched adolescent competitive swimmers and healthy males.

Physical therapists routinely compare range of motion measurements with the opposite side and/or with a standard for "normal" range. However, "normal" range may vary in relation to the individual's occupational and recreational movement patterns. The purposes of this study were 1) to compare the range of active physiological cervical rotation in 14- to 17-year-old male competitive swimmers (N = 40) and controls (N = 40) and 2) to investigate the relationship between the freestyle stroke breathing pattern and differences in right and left cervical rotation in swimmers. Analysis of variance determined if a group difference existed in goniometric measurement of cervical rotation. The experimental group demonstrated a significantly greater mean range of total active cervical rotation right (p = 0.002) than the control group. Swimmers also demonstrated a significantly greater (p = 0.0002) range of rotation on their breathing side (mean difference of 5 degrees). It was concluded that the differences in physiological cervical rotation between swimmers and nonswimmers and between sides in the swimmers were influenced by the swimming activity. The clinician needs to consider the influence of activity when assessing range of motion.

Adolescent↗
PubMed1998

Relationship between hip external rotation and turnout angle for the five classical ballet positions.

Functional turnout for each of the five classical ballet positions involves lower extremity motion that occurs primarily through hip external rotation. Ballet dancers often attempt to increase turnout angle through excessive motions at the foot or knee that may be associated with the development of musculoskeletal pathology. The purpose of this study was to further the understanding of turnout by identifying the relationship between available hip external rotation an functional turnout for the five classical ballet positions. Subjects were 20 female ballet dancers between the ages of 11 and 14. The investigators measured hip external rotation as the sum of passive external rotation available at both hips of each subject. Functional turnout angle was measured for each subject as the subject stood in each of the five classical ballet positions. A repeated measures analysis of variance and Tukey Honestly Significant Difference test indicated that hip external rotation was significantly less than functional turnout for the five classical ballet positions. No significant differences in functional turnout angle were present among the five ballet functional turnout angle for each of the five ballet positions. Hip external rotation should not be used to predict functional turnout for the five classical ballet positions. Turnout in first position may be useful as guide for functional turnout for the crossed foot positions: third, fourth, and fifth.

Adolescent↗
PubMed1996

Asymmetric optokinetic after-nystagmus induced by active or passive sustained head rotations.

Asymmetric vestibular function affects optokinetic after-nystagmus (OKAN) in man, but little is known about the involvement of cervical proprioception in the visual-vestibular interaction reflected as OKAN. We studied the effect of asymmetric cervical proprioception induced by active maximal, or passive 70 degrees sustained horizontal head rotations on OKAN in 16 healthy subjects. We evoked optokinetic nystagmus (OKN) by means of a whole-field optokinetic drum rotated at a velocity of 90 degrees/s for 60 s. Following left- and right-beating OKN, we recorded OKAN in complete darkness for 60 s by DC electro-oculography. Both passively and actively sustained head rotations significantly reduced the intensity of OKAN beating in the direction opposite to the head rotation, while OKAN beating in the direction of the head rotation remained unchanged. This resulted in significant asymmetry between OKAN beating in the direction of the head rotation vs. that in the opposite direction. The findings show that in normal subjects neck proprioception converges with visual and vestibular signals and affects subcortical OKN. Asymmetric neck proprioception from neck disorders may be hypothesized to induce dizziness or vertigo in situations where OKN is evoked.

Adult↗
PubMed2004

Spatial updating of virtual displays during self- and display rotation.

In four experiments, we examined observers' ability to locate objects in virtual displays while rotating to new perspectives. In Experiment 1, participants updated the locations of previously seen landmarks in a display while rotating themselves to new views (viewer task) or while rotating the display itself (display task). Updating was faster and more accurate in the viewer task than in the display task. In Experiment 2, we compared updating performance during active and passive self-rotation. Participants rotated themselves in a swivel chair (active task) or were rotated in the chair by the experimenter (passive task). A minimal advantage was found for the active task. In the final experiments, we tested similar manipulations with an asymmetrical display. In Experiment 3, updating during the viewer task was again superior to updating during the display task. In Experiment 4, we found no difference in updating between active and passive self-movement. These results are discussed in terms of differences in sources of extraretinal information available in each movement condition.

Humans↗