Plane Range Of Motion Research Articles

The influence of a bespoke unloader knee brace on gait in medial compartment osteoarthritis

Patients suffering from mild-to-moderate medial compartment knee osteoarthritis may be treated with an unloader knee orthosis. However, compliance has been shown to be an issue with such devices. The aim of this study was to identify the effects of a new design of knee unloader orthosis on specific gait parameters in patients with mild-to-moderate medial knee osteoarthritis. The gait of seven patients was assessed in two conditions: without an orthosis and when wearing a new design of unloader knee orthosis. Gait analysis was performed to determine alterations to the adduction moment, speed of walking, step length, cadence and knee sagittal plane range of motion during ambulation for the two test conditions. The knee adduction moment was significantly reduced (p = 0.001), and the speed of walking significantly increased (p < 0.001) when wearing the orthosis. However, a reduction in knee range of motion (p = 0.002) and an increase in step length (p < 0.001) were observed with the orthosis donned. Cadence was not significantly altered (p = 0.504). The use of a new design of unloader knee orthosis as a conservative treatment approach for patients with mild-to-moderate medial compartment osteoarthritis appears warranted. Various conservative modalities have been used to reduce pain and improve function in medial compartment osteoarthritis. A new design of an unloader knee orthosis has been developed and is shown to have immediate benefits in patients with mild medial knee osteoarthritis.

Range of motion of thoracic spine in sagittal plane

Imaging study of thoracic spine. The purpose of this study was to investigate dynamic alignment and range of motion (ROM) at all segmental levels of thoracic spine. Thoracic spine is considered to have restricted ROM because of restriction by the rib cage. However, angular movements of thoracic spine can induce thoracic compressive myelopathy in some patients. Although few previous studies have reported segmental ROM with regard to sagittal plane, these were based on cadaver specimens. No study has reported normal functional ROM of thoracic spine. Fifty patients with cervical or lumbar spinal disease but neither thoracic spinal disease nor compression fracture were enrolled prospectively in this study (34 males, 16 females; mean age 55.4 ± 14.7 years; range 27-81 years). After preoperative myelography, multidetector-row computed tomography scanning was performed at passive maximum flexion and extension position. Total and segmental thoracic kyphotic angles were measured and ROM calculated. Total kyphotic angle (T1/L1) was 40.2° ± 11.4° and 8.5° ± 12.8° in flexion and extension, respectively (P < 0.0001). The apex of the kyphotic angle was at T6/7 in flexion. Total ROM (T1/L1) was 31.7° ± 11.3°. Segmental ROM decreased from T1/2 to T4/5 but increased gradually from T4/5 to T12/L1. Maximum ROM was at T12/L1 (4.2° ± 2.1°) and minimum at T4/5 (0.9° ± 3.0°). Thoracic spine showed ROM in sagittal plane, despite being considered a stable region. These findings offer useful information in the diagnosis and selection of surgical intervention in thoracic spinal disease.

Effect of intensive conservative therapy on gait performance in patients with legg-calvé-perthes disease

Introduction: The hip joint may develop early osteoarthritis in patientswithPerthesdisease [1]. Physical examinationoften shows a limitation in range of motion (ROM) for hip extension, abduction and internal rotationaswell as anabductorweakness [2]. Conservative therapeutic training is an alternative to surgical interventions that can be used to improve altered biomechanics of the hip.While mechanisms of gait compensation in these patients have beenwell described [3], there is a lack of research on the effects of therapeutic training on gait performance. The purpose of the present study was to evaluate whether physiotherapy treatment could improve gait parameters in patients with Perthes disease. Patients/materials and methods: 18 patients with unilateral Perthes disease and a mean age of 6.2 (±1.9) years participated in this prospective study. Gait analysis was performed immediately before and 12 weeks after intensive therapeutic training. Kinematic datawere collected using an eight-cameraVicon system.One force plate (AMTI) was used to calculate mechanical power. The Helen Hayesmarker set [4] was applied to determine joint centers. All subjects walked barefoot at a self-selected speed along a 15m walkway. Differences were tested for significance using a paired ttest (significance level was set at P<0.05). The absolute symmetry index (ASI) was determined on the basis of the symmetry index of Robinson et al. [5]. Results: The thorax obliquity ROM was significantly decreased and hip power generation was significantly increased for the affected side during stance phase after therapeutic training. Moreover, the ASI showed a tendency toward an increasing symmetry between the affected and unaffected side for spatio-temporal parameters. In the clinical evaluation, the passive hip flexion increased significantly. However, the significantly decreased hip extension/flexion ROM of the affected side compared to the unaffected side did not change after therapeutic training during walking. Discussion& conclusions: These results suggest that therapeutic training can improve gait symmetry. In addition, as a result of the reduced Duchenne gait pattern, the mechanical energy generation by the hip extensors was increased. However, the decreased hip ROM in the sagittal plane did not change during walking after a therapeutic training period of 12 weeks. In order to avoid longterm gait impairment, sagittal hip flexibility should be taken into account andwas also observedduring thephysiotherapy treatment period. Therefore, gait analysis can be used to objectively evaluate the functionality of the involved joint, to indicate the discrepancy between passive ROM and dynamic situations as well as for potentially therapeutic treatment modification.

Differences in foot kinematics between young and older adults during walking

Our understanding of age-related changes to foot function during walking has mainly been based on plantar pressure measurements, with little information on differences in foot kinematics between young and older adults. The purpose of this study was to investigate the differences in foot kinematics between young and older adults during walking using a multi-segment foot model. Joint kinematics of the foot and ankle for 20 young (mean age 23.2 years, standard deviation (SD) 3.0) and 20 older adults (mean age 73.2 years, SD 5.1) were quantified during walking with a 12 camera Vicon motion analysis system using a five segment kinematic model. Differences in kinematics were compared between older adults and young adults (preferred and slow walking speeds) using Student's t-tests or if indicated, Mann–Whitney U tests. Effect sizes (Cohen's d) for the differences were also computed. The older adults had a less plantarflexed calcaneus at toe-off (−9.6° vs. −16.1°, d=1.0, p=<0.001), a smaller sagittal plane range of motion (ROM) of the midfoot (11.9° vs. 14.8°, d=1.3, p=<0.001) and smaller coronal plane ROM of the metatarsus (3.2° vs. 4.3°, d=1.1, p=0.006) compared to the young adults. Walking speed did not influence these differences, as they remained present when groups walked at comparable speeds. The findings of this study indicate that independent of walking speed, older adults exhibit significant differences in foot kinematics compared to younger adults, characterised by less propulsion and reduced mobility of multiple foot segments.

The Effect of Range of Motion After Single-level Discover Cervical Artificial Disk Replacement

A biomechanical study of cervical artificial disk replacement (CADR). This study aimed to investigate the range of motion (ROM) of the treated segment, the ROM of the adjacent segments, the global ROM in the sagittal plane, and the total neck ROM in the 3 cardinal planes after single-level Discover CADR. CADR could theoretically preserve the motion function of the treated segment without affecting the adjacent segments significantly. Although previous studies have reported excellent clinical outcomes and ROM of the treated segment after CADR, few studies have focused on the ROM of the adjacent segments, the global ROM, and the total neck motion. C5/6 Discover CADR was performed in 58 patients (37 male and 21 female) between September 2008 and September 2010. Anteroposterior, lateral, and flexion-extension lateral radiographies were performed before operation and at the 1-year follow-up. Clinical parameters, including the Japanese orthopedic association score, the neck disability index, and the visual analogue scale, were evaluated. The ROM of the treated segment (C5/6) and the adjacent segments (C4/5 and C6/7) and the global ROM (C2/7) were measured by radiography. To evaluate the total neck ROM, the cervical ROM device was advocated. Preoperative and postoperative data were compared using the paired t test. The Japanese orthopedic association score was 14.3 at the 1-year follow-up as compared with the preoperative score of 8.7. Other scoring systems had improved postoperatively, including the neck disability index from 85.1 to 68.6 and the visual analogue scale from 7.8 to 3.3. Compared with the preoperative ROM, the postoperative ROM increased by 3.0 degrees (27.0%) in C5/6, 1.3 degrees (13.7%) in C4/5, and 1.8 degrees (17.6%) in C6/7. The postoperative global ROM also increased by 6.7 degrees (15.2%) compared with preoperative global data. Compared with the preoperative total neck motion, the postoperative total neck motion increased by 8.3 degrees (9.3%) in the sagittal plane and 6.1 degrees (7.7%) in the coronal plane. There was an insignificant increase of 0.8 degrees (0.6%) in the horizontal plane. This study demonstrated that the single-level Discover CADR increased the ROM of the treated segment and the adjacent segments. There was also an increase in the global ROM and the total neck motion in the sagittal and the coronal planes, although there was no significant difference in the horizontal plane before and after operation.

Hindfoot Motion Following STAR Total Ankle Arthroplasty

One of the rationales for total ankle arthroplasty (TAA) is that it may retard the changes of hypermobility and accelerated arthritis in the hindfoot after ankle arthrodesis. Until recently, it has not been possible to quantify or even objectively demonstrate biomechanical findings to substantiate the theory that postsurgical biomechanical changes in the ankle produce changes in the kinematics of the hindfoot. Standard gait analysis has treated the foot as a single biomechanical unit. This study was undertaken to describe the hindfoot motion following Scandinavian Total Ankle Replacement (STAR) TAA by using multisegment foot model gait analysis. Forty-six patients with a mean age of 66 years underwent a 3D gait analysis following TAR. Mean interval between surgery and gait analysis was 4.9 years (range 2 to 9). The contralateral limb was used as control for each patient. Temporospatial variables and kinematic parameters were studied. Temporospatial results showed statistically significant differences. Stance time on the affected side was 61.1% ± 2.2% of the gait cycle compared to 63.2% ± 2.1% for the unaffected side. Step length was 55.6 cm ± 10 on the affected side compared to 53.9 cm ± 10 for the unaffected side. Kinematics results were statistically significant: Ankle range of motion (ROM) on the arthroplasty side was 16.8 ± 4.5 degrees compared to 23.6 ± 5.0 on the unaffected side. Sagittal plane ROM was 12.7 ± 4.2 degrees on the arthroplasty side and 17.3 ± 3.5 degrees on the unaffected side. Coronal plane ROM was 4.7 ± 2.4 degrees on the arthroplasty side and 7.5 ± 2.4 degrees on the unaffected side. Transverse plane ROM on the arthroplasty side was 4.1 ± 1.5 degrees and 4.9 ± 1.6 on the unaffected side. This study showed that, in addition to previously documented diminution in sagittal plane motion and gait velocity, some of the residual abnormalities of gait following TAR were comprised of differences in hindfoot function. These results relate to the growing recognition of the importance of understanding hindfoot mechanics apart from those of the tibiotalar joint. Level III, comparative case series.

Repeatability of stance phase kinematics from a multi-segment foot model in people aged 50 years and older

Confidence in 3D multi-segment foot models has been limited by a lack of repeatability data, particularly in older populations that may display unique functional foot characteristics. This study aimed to determine the intra and inter-observer repeatability of stance phase kinematic data from a multi-segment foot model described by Leardini et al. [2] in people aged 50 years or older. Twenty healthy adults participated (mean age 65.4 years SD 8.4). A repeated measures study design was used with data collected from four testing sessions on two days from two observers. Intra (within-day and between-day) and inter-observer coefficient of multiple correlations revealed moderate to excellent similarity of stance phase joint range of motion (0.621–0.975). Relative to the joint range of motion (ROM), mean differences (MD) between sessions were highest for the within-day comparison for all planar ROM at the metatarsus-midfoot articulation (sagittal plane ROM 5.2° vs. 3.9°, MD 3.1°; coronal plane ROM 3.9 vs. 3.1°, MD 2.3°; transverse plane ROM 6.8° vs. 5.16°, MD 3.5°). Consequently, data from the metatarsus-midfoot articulation in the Istituto Ortopedico Rizzoli (IOR) foot model in adults aged over 50 years needs to be considered with respect to the findings of this study.

The effect of biceps adhesions on glenohumeral range of motion: a cadaveric study

Previous studies have demonstrated that the humerus slides along the long head of the biceps tendon (LHBT). Blocking this motion may result in decreased glenohumeral (GH) range of motion (ROM). The goal of the study was to characterize the excursion of the LHBT and measure the effect of biceps adhesions on GH ROM. A custom biomechanical testing setup was used to measure the excursion of the LHBT and rotation of the humerus at 0°, 15°, 30°, 60°, and 90° of GH abduction in the scapular plane. An in situ biceps tenodesis with the biceps anchor still intact, thus simulating biceps adhesions, was sequentially performed in 2 positions: 0° abduction and maximum external rotation, followed by 0° abduction and maximum internal rotation. The effect of tenodesis on ROM was measured. There was an average excursion of 19.4 ± 5.4 mm of the LHBT as the humerus was taken through ROM in the scapular plane. Tenodesis in 0° abduction and maximum internal rotation resulted in a significant decrease in GH external rotation of 47.3° ± 12.2° (P = .007) with the arm in 0° abduction. Tenodesis in maximum internal rotation limited rotation significantly, such that in situ tenodesis without proximal tenotomy should not be performed. Furthermore, in situations where the biceps is at risk for scarring, such as proximal humeral fractures, shoulder arthroplasty, and the stiff shoulder, the biomechanical consequence of biceps adhesions may be similar to in situ tenodesis and may limit ROM and clinical outcomes.

Reliability and Accuracy in Three-Dimensional Gait Analysis: A Comparison of Two Lower Body Protocols

The standard Plug-in-Gait (PiG) protocol used in three-dimensional gait analysis is prone to errors arising from inconsistent anatomical landmark identification and knee axis malalignment. The purpose of this study was to estimate the reliability and accuracy of a custom made lower body protocol (MA) compared with the PiG protocol. Twenty-five subjects volunteered to evaluate the intertrial reliability. In addition, intersession reliability was examined in 10 participants. An indirect indicator of accuracy according to the knee varus/valgus and flexion/extension range of motion (ROM) was used. Regarding frontal plane knee angles and moments as well as transverse plane motions in the knee and hip joint, the intersession errors were lower for the MA compared with the standard approach. In reference to the knee joint angle cross-talk, the MA produced 4.7° more knee flexion/extension ROM and resulted in 6.5° less knee varus/valgus ROM in the frontal plane. Therefore, the MA tested in this study produced a more accurate and reliable knee joint axis compared with the PiG protocol. These results are especially important for measuring frontal and transverse plane gait parameters.

Effects of nonlinearity in the materials used for the semi-rigid pedicle screw systems on biomechanical behaviors of the lumbar spine after surgery**This work was presented at the 8th China–Korea Symposium on Biomaterials and Nano-Bio Technology (Pyeongchang, Korea, Dec. 13–17 2010).

Recently, various types of semi-rigid pedicle screw fixation systems have been developed for the surgical treatment of the lumbar spine. They were introduced to address the adverse issues commonly found in traditional rigid spinal fusion-–abnormally large motion at the adjacent level and subsequent degeneration. The semi-rigid system uses more compliant materials (nitinol or polymers) and/or changes in rod design (coiled or twisted rods) as compared to the conventional rigid straight rods made of Ti alloys (E = 114 GPa, υ = 0.32). However, biomechanical studies on the semi-rigid pedicle screw systems were usually limited to linear modeling of the implant and anatomic elements, which may not be capable of reflecting realistic post-operative motions of the spine. In this study, we evaluated the effects of nonlinearity in materials used for semi-rigid pedicle screw fixation systems to evaluate the changes in biomechanical behaviors using finite element analysis. Changes in range of motion (ROM) and center of rotation (COR) were assessed at the operated and adjacent levels. Actual load–displacement results of the semi-rigid rod from mechanical test were carried out to reflect the nonlinearity of the implant. In addition, nonlinear material properties of various spinal ligaments studies were used for the finite element modeling. The post-operative models were constructed by modifying the previously validated intact model of the L1-S1 spine. Eight different post-operative models were made to address the effects of nonlinearity—with a traditional stiffness modulus rod (with linear ligaments, case 1; with nonlinear ligaments, case 5), with a rigid rod (with linear ligaments, case 2; with nonlinear ligaments, case 6), with a soft rod (with linear ligaments, case 3; with nonlinear ligaments, case 7), and with a nonlinear rod (with linear ligaments, case 4; with nonlinear ligaments, case 8). To simulate the load on the lumbar spine in a neutral posture, follower load (400 N) was applied and then the hybrid loading condition was applied to measure the ROM and COR in the sagittal plane. The more the nonlinearity was included in the model the closer the motion behavior of the device was to that of the intact spine. Furthermore, our results showed that the nonlinearity of the semi-rigid rod was a more sensitive factor than the nonlinearity of the spinal ligaments on biomechanical behavior of the lumbar spine after surgery. Therefore, for better understanding of the surgical effectiveness of the spinal device, more realistic material properties such as nonlinearity of the device and anatomic elements should be considered. In particular, the nonlinear properties of the semi-rigid rod were considered more than the nonlinearity of spinal ligaments.

Children's rearfoot and midfoot motion while walking in school shoes

navicular, 1 st and 5 th metatarsal heads and hallux. Rearfoot motion was measured with a wand marker cluster through a window in the shoe. A standing reference trial was used to embed segment axes and thence to calculate motion of the distal segment relative to the proximal segment. Data were normalised to the stance phase which was sub-divided from the anterior/posterior force data as: contact period (initial contact - maximum negative force); midstance (maximum negative force zero) and propulsion (positive force - toe-off). Results Five boys and seven girls participated in the study (mean age 9 years, range 5-13 years). During the contact period shoes decreased midfoot range of motion (ROM) in the frontal plane from 3.4° to 1.7° (p=0.002) and in the transverse plane from 22.0° to 11.6° (p<0.001). No significant difference in ROM occurred during midstance at either the rearfoot or midfoot. During propulsion shoes reduced rearfoot ROM in the frontal plane from 12.0° to 9.6° (p=0.026) and midfoot ROM in the sagittal plan from 19.6° to 10.8° (p<0.001) and in the transverse plan from 10.1° to 4.3° (p<0.001). Conclusions Traditional school shoes restrict children’s foot motion during walking particularly at the midfoot during the contact period and propulsion phases of gait. The medium and long-term impacts of these changes are the focus of further research. The impact of school shoes on foot motion should be considered when assessing the paediatric patient and evaluating the effect of shoe or in-shoe interventions.

Foot kinematics in people with medial compartment knee osteoarthritis

Objectives. Foot orthoses are commonly used in the management of knee OA, although the relationship between foot function and knee OA is still unclear. The purpose of the study was to examine foot function during walking in people with and without medial compartment knee OA. Methods. Motion of the tibia, rearfoot and forefoot in 32 patients with medial compartment knee OA and 28 age-matched control subjects was investigated. Multivariate analysis was used to compare the groups. Results. The knee OA group contacted the ground with a more everted rearfoot, demonstrated greater peak rearfoot eversion and exhibited reduced rearfoot frontal plane range of motion and reduced rearfoot peak inversion. The tibia was more internally rotated and laterally tilted throughout the gait cycle, with reduced peak external rotation. Conclusion. People with medial compartment knee OA exhibit altered foot kinematics during gait that are indicative of a less mobile, more everted foot type. The presence and degree of tibial malalignment and the available rearfoot range of motion during walking may affect individual responses to load-altering interventions, such as foot orthoses and footwear modifications. Trial registration: Australian New Zealand Clinical Trials Registry, www.anzctr.org.au/, ACTRN

Arthritis predicting factors in distal intraarticular radius fractures

Intra-articular malunion with step off and gap formation is claimed to be crucial for radiocarpal degeneration. In addition to well-defined intraarticular malunion, the shape of the distal radius is important for unaffected wrist function. In typical intra-articular fracture patterns with a dorsoulnar and palmar ulnar fragment, alterations of the shape of the articular surface, in a kind of a cavity, without obvious step off can be observed. The aim of the present study is to determine the residual articular deformity following intra-articular radius fractures and to analyze their impact on the final clinical and radiological outcome. Eighty one patients with dorsally displaced distal intraarticular radius fractures were followed up for a mean period of 9 years. Surgical treatment of all patients included open reduction, plate fixation and corticocancellous bone grafting. Radiological measurements included palmar tilt, radial inclination and radial shortening as defined by ulnar variance, intra-articular Stepps and the measurement of the anteroposterior distance of the radial joint surface. Clinical assessment included active range of motion (ARM) of the wrist, pain according to a visual analogue scale (VAS), grip power, working ability, Disability of Arm, Shoulder and Hand Score (DASH Score). Articular malunion in the form of a cavity in the sagittal plane measured 4.8mm, 1.3mm more than on the non-injured side. Anteroposterior distance measured 20.6mm, 2.1mm more than on the non-injured side. Articular step-off and gap was noticed in 11 patients. At the final follow-up examination, there was a significant difference in articular cavity depth and the anteroposterior distance between arthritis stage I and II. Arthritis stage was associated with the range of motion (ROM) in the sagittal plane, but had no significant influence on the DASH, pain level, grip strength and ROM in the frontal plane. ORIF leads to predictable results in the restoration of length and form of the distal radius. Increasing the articular cavity depth should be avoided to prevent degenerative arthritis at the radiocarpal joint at long-term follow-up visits.

Effect of Intrathecal Baclofen Bolus Injection on Lower Extremity Joint Range of Motion During Gait in Patients With Acquired Brain Injury

Horn TS, Yablon SA, Chow JW, Lee JE, Stokic DS. Effect of intrathecal baclofen bolus injection on lower extremity joint range of motion during gait in patients with acquired brain injury. Objectives To evaluate lower extremity joint range of motion (ROM) during gait before and after intrathecal baclofen (ITB) bolus administration, and to explore the relation between changes in ROM and concurrent changes in gait speed and muscle hypertonia. Design Case series. Setting Tertiary care rehabilitation center. Participants Adults (N=28) with muscle hypertonia due to stroke, trauma, or anoxia. Interventions 50-μg ITB bolus injection via lumbar puncture (75 and 100μg in 2 cases). Main Outcome Measures Ashworth score, self-selected gait speed, and sagittal plane ROMs in hip, knee, and ankle joints before and 2, 4, and 6 hours after ITB bolus. Results A significant decrease in the mean Ashworth score on the more involved side (2.0 to 1.3) and an increase in gait speed (41 to 47cm/s) were noted at different intervals after ITB bolus injection. Ankle ROM significantly increased on the more involved (13° to 15°, P<.01) and less involved (22° to 24°, P<.05) sides. ROM significantly improved, significantly worsened, or showed no significant change in 42%, 34%, and 24% of individual joints, respectively. The peak change in ROM did not coincide with the peak decrease in Ashworth score. Peak changes in ROM and speed coincided more often ( P<.001) in participants who increased gait speed after ITB bolus compared with those who decreased speed. The absolute change in ROM after ITB bolus injection correlated better with the concurrent changes in speed ( r=.41, P<.001) than with the baseline speed ( r=.18, P<.05). Conclusions ITB bolus injection produces variable changes in joint ROM during gait, with significant improvements in the ankles only. Timing and magnitude of peak changes in ROM are associated with concurrent changes in speed but not muscle hypertonia.

Cycling with noncircular chainring system changes the three-dimensional kinematics of the lower limbs

This study investigated the three-dimensional (3-D) pedaling kinematics using a noncircular chainring system and a conventional system. Five cyclists pedaled at their preferred cadence at a workload of 300 W using two crank systems. Flexion/extension of the hip, knee and ankle as well as shank rotation, foot adduction/abduction, and pedal angle were measured. Joint range of motion (ROM) and angular displacements were compared between the systems. Sagittal plane ROM was significantly greater (P < 0.05) at the hip (noncircular system = 39 ± 3°; conventional system = 34 ± 4°) the knee (noncircular system = 69 ± 4°; conventional system = 57 ± 10°), and ankle (noncircular system = 21 ± 2°; conventional system = 19 ± 4°) resulting in greater pedal ROM (noncircular system = 43 ± 3°; conventional system = 37 ± 5°) while using the noncircular system. Shank rotation ROM was significantly lower (P < 0.05) while using the noncircular chainring (noncircular system = 10 ± 1°; conventional system = 14 ± 1°). These results support a significant effect of the noncircular chainring system on pedaling kinematics during submaximal exercise.

Effect of a novel interspinous implant on lumbar spinal range of motion

Interspinous devices have been introduced to provide a minimally invasive surgical alternative for patients with lumbar spinal stenosis or foraminal stenosis. Little is known however, of the effect of interspinous devices on intersegmental range of motion (ROM). The aim of this in vivo study was to investigate the effect of a novel minimally invasive interspinous implant, InSwing, on sagittal plane ROM of the lumbar spine using an ovine model. Ten adolescent Merino lambs underwent a destabilization procedure at the L1-L2 level simulating a stenotic degenerative spondylolisthesis (as described in our earlier work; Spine 15:571-576, 1990). All animals were placed in a side-lying posture and lateral radiographs were taken in full flexion and extension of the trunk in a standardized manner. Radiographs were repeated following the insertion of an 8-mm InSwing interspinous device at L1-L2, and again with the implant secured by means of a tension band tightened to 1 N/m around the L1 and L2 spinous processes. ROM was assessed in each of the three conditions and compared using Cobb's method. A paired t-test compared ROM for each of the experimental conditions (P < 0.05). After instrumentation with the InSwing interspinous implant, the mean total sagittal ROM (from full extension to full flexion) was reduced by 16% from 6.3 degrees to 5.3 +/- 2.7 degrees. The addition of the tension band resulted in a 43% reduction in total sagittal ROM to 3.6 +/- 1.9 degrees which approached significance. When looking at flexion only, the addition of the interspinous implant without the tension band did not significantly reduce lumbar flexion, however, a statistically significant 15% reduction in lumbar flexion was observed with the addition of the tension band (P = 0.01). To our knowledge, this is the first in vivo study radiographically showing the advantage of using an interspinous device to stabilize the spine in flexion. These results are important findings particularly for patients with clinical symptoms related to instable degenerative spondylolisthesis.

The Effects of Orthotics on Lower Extremity Kinematic Variability During Running

Abnormal foot mechanics during running may affect the kinematics of the lower extremities and predispose individuals to injuries of the foot, ankle, and knee. Orthotics are often used to correct these abnormal gait mechanics. Since previous research indicates that changes invariability may be related to running injuries (Hamill et al., 1999), understanding the effects of orthotics on movement variability of the lower extremities may be useful for injury prevention. PURPOSE: To examine the effects of an orthotic on lower extremity kinematic variability during running. METHODS: Thirty male and female runners identified as being excessive pronators participated in this study. Subjects were required to perform two testing sessions in which they ran with and without orthotics; all subjects used the same model of orthotic and running shoe. During both testing sessions, the subjects ran on a treadmill at a velocity of 3.35 m/s for 15 min. A motion capture system was used to record the position of light emitting diodes placed on the foot, shank, and thigh segments at 100 Hz for 50 complete gait cycles during the last 5 min of each testing session. Range of motion (ROM), peak angular velocity (PAV), and peak angular acceleration (PAA) for the ankle and knee joints were calculated for the frontal, sagittal, and transverse planes of motion according to the methods outlined by Eng and Pierrynowski (1994). Variability was quantified as the intra-subject standard deviation for ROM, PAV, and PAA. A two-way analysis of variance was used to assess the effects of orthotics on ROM, PAV, and PA A variability. RESUITS: It was found that orthotics lead to significant increases in variability for ankle joint ROM in the transverse plane (from 9.6±1.4° to 12.0±2.7°; p<0.001), knee joint ROM in the transverse plane (from 8.4±1.3° to 9.6±2.1°; p<0.01), knee joint ROM in the frontal plane (from 7.6±1.6 to 9.2±2.3°; p<0.05), and knee joint PAV in the sagittal plane (from 438.6±33. 1°/s to 429.0±41.9°/s; p<0.05). While there was not a significant difference in ankle joint eversion ROM in the frontal plane when using orthotics, there was a strong trend towards increased variability (from 13.1±1.6° to 14.1±1.9°). CONCLUSIONS: Orthotics are commonly used to correct abnormal gait mechanics. However, this study demonstrates that orthotics can increase the variability of lower extremity kinematics during running; this increase in variability may predispose individuals to injury. Further research is necessary to determine the relationship between lower extremity kinematic variability and running injuries. This investigation was supported by a grant from the Mid-America Athletic Trainers Association.

Kinematics of the midtarsal joint during standing leg rotation.

Building on previous work that was cadaver based or involved invasive techniques, this study quantifies the kinematics of an approximation of the midtarsal joint with a noninvasive method. Three-dimensional kinematic data describing the motion of the forefoot and heel during transverse plane rotation of the leg were collected from 25 subjects by means of reflective markers and four infrared cameras. The motion between these segments was assumed to be the best possible clinical approximation of the midtarsal joint. The kinematic characteristics of the midtarsal joint were described in terms of the range and direction of motion in each cardinal body plane, the ratio of the range of motion in each plane, and the orientation of the axis of rotation. The characteristics of the midtarsal joint changed during the range of motion; thus, multiple axes of rotation could be calculated and joint characteristics were varied among subjects. The results of this in vivo method were generally consistent with those of cadaver studies and invasive in vivo studies.

The influence of age and gender on lumbar spine sagittal plane range of motion. A study of 1126 healthy subjects.

Inclinometers have been recommended for the measurement of lumbar spine range of motion (ROM) in the assessment of disability. Range of motion thresholds that determine impairment ratings have been established without regard to age and gender or variances of the measures. This investigation determined the effect of gender and age on lumbar spine sagittal plane ROM in 1126 healthy male and female volunteers. Results indicate that distinct differences exist between men and women in flexion angle and extension angle, whereas little difference exists between genders for total lumbar sagittal ROM. Total sagittal ROM, flexion angle, and extension angle declined as age increased. Because of the high degree of variability in the measurements, detecting impairment in ROM with this method is problematic.

Structural transformations indistinquishable by point-count stereology

Confidence in 3D multi-segment foot models has been limited by a lack of repeatability data, particularly in older populations that may display unique functional foot characteristics. This study aimed to determine the intra and inter-observer repeatability of stance phase kinematic data from a multi-segment foot model described by Leardini et al. [2] in people aged 50 years or older. Twenty healthy adults participated (mean age 65.4 years SD 8.4). A repeated measures study design was used with data collected from four testing sessions on two days from two observers. Intra (within-day and between-day) and inter-observer coefficient of multiple correlations revealed moderate to excellent similarity of stance phase joint range of motion (0.621–0.975). Relative to the joint range of motion (ROM), mean differences (MD) between sessions were highest for the within-day comparison for all planar ROM at the metatarsus-midfoot articulation (sagittal plane ROM 5.2° vs. 3.9°, MD 3.1°; coronal plane ROM 3.9 vs. 3.1°, MD 2.3°; transverse plane ROM 6.8° vs. 5.16°, MD 3.5°). Consequently, data from the metatarsus-midfoot articulation in the Istituto Ortopedico Rizzoli (IOR) foot model in adults aged over 50 years needs to be considered with respect to the findings of this study.