Development of a noninvasive measure of pelvic and hip angles in seated posture

OBJECTIVE: To develop a valid noninvasive means to measure pelvic tilt and hip angle in seated posture. DESIGN: Validation cohort study using radiographs as a criterion standard for pelvic posture. SETTING: Rehabilitation hospital. PARTICIPANTS: Volunteer sample of 10 adult men with no known physical disability. INTERVENTIONS: Radiographs were taken as subjects sat in erect, anterior, and posterior postures. An electromagnetic tracking device was as a pointer to digitize the anterior superior and posterior superior iliac spines and as a 6 degrees of freedom (df) sensor mounted on the thigh and sacrum. MAIN OUTCOME MEASURES: Variables included pelvic tilt and hip flexion angle. Intra- and interrater reliability of radiographic measures was determined by using intraclass correlation coefficient comparison of the results from 2 investigators. Validity was determined by comparing noninvasive measures of pelvic and hip angles to radiographic measures by using correlation, analysis of variance (ANOVA), and regression. RESULTS: Reliability of radiographic measures of pelvic tilt and hip angles were >/=.98. Pelvic tilt comparison: pointer: r=.89, R(2)=.80; 6-df sensor: r=.91, R(2)=.83; hip angle comparison using 6-df sensor: r=.78 with average difference of 4.25 degrees. ANOVA showed that differences between all invasive and noninvasive measures did not differ significantly (P>.05). CONCLUSION: Results indicated excellent reliability of radiographic analysis techniques and represented an improvement over previously published techniques. Noninvasive measures of pelvic tilt and hip angle were shown to be valid.     

Relationship between iliopsoas muscle thickness and hip angle during squats in different pelvic positions

[Purpose] This study aimed to investigate the relationships among the changes in iliopsoas muscle thickness, hip angle, and lower limb joint moment during squatting in different pelvic positions to help in performing hip-dominant squatting exercises. [Participants and Methods] The participants were seven healthy adult males. The measurement task consisted of squatting with 60 degrees of knee flexion in three positions: the anterior, neutral, and posterior pelvic tilt positions. The iliopsoas muscle thickness was measured in the center of the inguinal region using ultrasonography. A three-dimensional motion analysis system was used to measure the joint angles and joint moments. [Results] There were no significant differences in pelvic angles between the pelvic positions. The hip angle differences were significantly higher in the anterior and neutral pelvic tilt positions compared to those in the posterior tilt position. Only the anterior pelvic tilt position had a significantly positive correlation with iliopsoas muscle thickness and hip angle differences. [Conclusion] Squatting in the neutral or posterior pelvic tilt position was not associated with hip angle and iliopsoas muscle thickness changes, whereas squatting in an anterior pelvic tilt position was associated with changes in the iliopsoas muscle thickness and hip flexion angle. Our findings suggest that activation of the iliopsoas muscle might be necessary to promote hip-dominant squatting.Key words: Squats, Iliopsoas muscle, Pelvic position     

Intrinsic and imposed hamstring length influence posterior pelvic rotation during hip flexion

BACKGROUND: The contribution of posterior tilt of the pelvis (pelvic rotation) to hip flexion has been described for individuals who are standing, supine, and suspended. The effects of intrinsic and imposed hamstring length on the motion have not been investigated in a controlled manner. This study investigated the influence of intrinsic and imposed hamstring length on pelvic rotation during bilateral active hip flexion. METHODS: Intrinsic hamstring length was characterized by the maximal active straight leg raise angle. Hamstring length was imposed by immobilizing the knees in 0 degrees, 45 degrees, and 90 degrees of flexion. Pelvic and thigh segments were marked with reflective spheres. Subjects' saggital plane motion was captured using computerized motion analysis during bilateral hip flexion while both knees were immobilized in three positions. Multifactorial analysis of variance was employed to show the effect of intrinsic and imposed hamstring length on pelvic rotation. FINDINGS: Pelvic rotation occurred throughout the hip flexion range of motion. Pelvic rotation was influenced significantly by hip flexion angle, knee position, the interaction between hip flexion angle and knee position, and the interaction between hip flexion angle, knee position, and active straight leg raise angle. INTERPRETATION: Both intrinsic and imposed hamstring length influence pelvic rotation during bilateral hip flexion. These influences should be considered by clinicians who have individuals engage in hip flexion maneuvers.     

Reliability and validity of four instruments for measuring lumbar spine and pelvic positions

We studied the between-therapist reliability and the validity of four instruments in measuring lumbar spine curvature and pelvic tilt. The four instruments and their measurements were 1) a tape measure to measure the change in lumbar curvature during trunk flexion; 2) a gravity goniometer to measure pelvic angle and lumbar curvature during stance, trunk flexion, and trunk extension; 3) a parallelogram goniometer to measure lumbar curvature during stance, trunk flexion, and trunk extension; and 4) a standard goniometer to measure the angle between wooden pointers mounted perpendicularly to the spine to obtain pelvic angle and lumbar curvature during stance, trunk flexion, and trunk extension. We found no single instrument to be the most reliable or valid. Between-therapist reliability ranged from .64 to .93 (Pearson product-moment correlation) and from .60 to .92 (interclass correlation coefficient). The validities of the instruments compared with measurements from roentgenograms generally were low, ranging from -.13 to .76 (Pearson product-moment correlation) and -.73 to -.05 (interclass correlation coefficient).     

Clinical reliability and usability of smartphone goniometers for hip range of motion measurement

[Purpose] This study aimed to utilize the objective measurements and a survey questionnaire for assessing the intra- and inter-rater reliability, measurement time, and usability of a smartphone application type of goniometer to measure the hip joint angles. [Participants and Methods] Three examiners (physiotherapists) measured the hip joint range of motion using universal and smartphone goniometers on 30 daycare center rehabilitation patients. Reliability was calculated using the intra-class correlation coefficient. The examiners completed a questionnaire survey for assessing the usability of the goniometers. [Results] The intra-rater reliability was high, but the inter-rater reliability was low. Measurement times using the two instruments showed no difference. The usability questionnaire findings suggested that the smartphone goniometer was easier to use than the universal goniometer. [Conclusion] Reliability within the raters was high, but reliability among the raters was low. However, both goniometric devices provided a satisfactory range of motion measurement data when a single evaluator used the same device for all measurements.     

A Sloped Seat Wedge Can Change the Kinematics of the Lumbar Spine of Seated Workers with Limited Hip Flexion

[Purpose] The purpose of this study was to determine whether a wedge type seat decreases the lumbar flexion angle of seated workers with limited hip flexion. [Subjects] Twelve sedentary workers with limited hip flexion were recruited. [Methods] Three seat surfaces were used: a level surface, a forward-inclining wedge, and a backward-reclining wedge. The angles of lumbar flexion and pelvic tilt were measured using a three-dimensional motion analysis system. Differences in kinematic data of the subjects seated on the three seat surfaces were analyzed using repeated one-way analysis of variance. [Results] The degree of lumbar flexion decreased significantly when using the forward-inclining wedge compared with the level surface and backward-reclining wedge. [Conclusion] These findings suggest that sitting on a forward-inclining wedge may be useful for minimizing the compensatory lumbar flexion of individuals with limited hip flexion who work in a seated position.Key words: Kinematics, Limited hip flexion, Seat wedge     

Differences in lumbar and pelvic angles and gluteal pressure in different sitting postures

[Purpose] To investigate the effects of erect sitting, slouched posture with cross-legged sitting, and erect posture with cross-legged sitting on the lumbar and pelvic angles, and gluteal pressure. [Subjects] For the experiments, 17 healthy women were recruited. [Methods] All subjects were asked to perform three sitting postures: erect sitting, slouched posture with cross-legged sitting, and erect posture with cross-legged sitting. Lumbar and pelvic angles were measured using a three-dimensional motion-capture system, and gluteal pressure was measured using a pressure mat. [Results] Compared to erector sitting, slouched posture with cross-legged sitting showed significantly greater lumbar flexion, posterior pelvic tilt, and left pelvic tilt. Compared to erect sitting, erect posture with cross-legged sitting showed significantly greater lumbar flexion and posterior pelvic tilt. Compared to erect posture with cross-legged sitting, slouched posture with cross-legged sitting showed significantly greater lumbar flexion and posterior pelvic tilt. Compared to erect sitting and erect posture with cross-legged sitting, slouched posture with cross-legged sitting showed significantly greater left gluteal pressure; there was no significant difference in right gluteal pressure. [Conclusion] An erect posture can reduce changes in lumbar and pelvic angles, and gluteal pressure compared to a slouched posture during cross-legged sitting.Key words: Cross-legged sitting, Lumbar and pelvic angles, Gluteal pressure     

Modification of sitting posture of patients with hemiplegia using seat boards and backboards

The purpose of this study was to evaluate and compare the effects of using seat boards only and a combination of seat boards and backboards on wheelchair posture. Forty-one patients with hemiplegia secondary to cerebrovascular accidents were assigned sequentially to 1) a group that used seat boards only (SB Group), 2) a group that used both seat boards and backboards (SBB Group), or 3) a group that used no boards (Control Group). The SB and SBB Groups used the boards throughout rehabilitation. Wheelchair sitting posture was measured at entry to and discharge from the rehabilitation program. The SB and SBB Groups were measured with and without boards. Anterior-posterior pelvic tilt, lumbar lordosis, thoracic kyphosis, lateral flexion, and lateral pelvic tilt were measured using a gravity goniometer, photographs, and calipers. Use of seat boards was associated with a decreased lateral pelvic tilt of 2.3 degrees at discharge while the seat boards were in place. The use of seat boards and backboards combined was associated with decreased lateral pelvic tilt of 3.1 and 1.6 degrees, increased anterior pelvic tilt of 13.1 and 11.1 degrees, and decreased thoracic kyphosis of 13.0 and 14.2 degrees at entry to and at discharge from the rehabilitation program, respectively, while the boards were in place. At the end of rehabilitation when the boards were removed, no long-term postural changes had occurred in the treatment groups compared with the Control Group. This study demonstrated that seat boards and backboards in wheelchairs improve certain postural deviations of patients with hemiplegia, but that these improvements are not maintained when the boards are removed after 5 to 10 weeks of use.     

Sources of goniometric error at the elbow

We assessed accuracy and potential sources of error in goniometry by using a photographic reference standard. Forty-six physical therapy students measured elbow positions using plastic or steel goniometers following three protocols: ALIGN, in which the investigator's elbow was splinted and bony landmarks were prelabeled; ASSIGN, in which the elbow remained splinted but labels were removed; and PROM, in which raters measured full passive flexion of the elbow. F ratios of variances indicated that alignment of goniometer, identification of landmarks, and variations in manual force during PROM contributed to goniometric error and that accuracy of joint angle measurement by photography (s +/- 0.7-1.1 degrees) was greater than by standard goniometry (s +/- 2.4-3.4 degrees). Analysis of variance and post-hoc test results unexpectedly indicated that all but one goniometric mean differed statistically (p less than .05) from associated photographic means. Small systematic errors in alignment of goniometers and identification of reference landmarks may have accounted for these differences. The results indicate that relatively inexperienced raters should be able to use goniometers accurately to measure elbow position when given standardized methods to follow.     

Effects of lumbar stabilization using a pressure biofeedback unit on muscle activity and lateral pelvic tilt during hip abduction in sidelying

OBJECTIVE: To assess the effects of lumbar spine stabilization using a pressure biofeedback unit on the electromyographic activity and angle of lateral pelvic tilt during hip abduction in a sidelying position. DESIGN: Comparative, repeated-measures study. SETTING: University research laboratory. PARTICIPANTS: Eighteen able-bodied volunteers (9 men, 9 women) with no history of pathology. INTERVENTION: Subjects were instructed to perform hip abduction in a sidelying position in both the preferred hip abduction (PHA) and hip abduction with lumbar stabilization (HALS). A pressure biofeedback unit was used for lumbar stabilization. MAIN OUTCOME MEASURES: Surface electromyography was recorded from the quadratus lumborum, gluteus medius, internal oblique, external oblique, rectus abdominis, and multifidus muscles. Kinematic data for lateral pelvic tilt angle were measured using a motion analysis system. Dependent variables were examined with 2 (PHA vs HALS) x 2 (men vs women) analysis of variance. RESULTS: Significantly decreased electromyographic activity in the quadratus lumborum (PHA, 60.39% +/- 15.62% of maximum voluntary isometric contraction [MVIC]; HALS, 27.90% +/- 13.03% of MVIC) and significantly increased electromyographic activity in the gluteus medius (PHA, 25.03% +/- 10.25% of MVIC; HALS, 46.06% +/- 21.20% of MVIC) and internal oblique (PHA, 24.25% +/- 18.10% of MVIC; HALS, 44.22% +/- 20.89% of MVIC) were found when the lumbar spine was stabilized. Lateral pelvic tilt angle (PHA, 13.86 degrees +/- 4.66 degrees; HALS, 5.55 degrees +/- 4.16 degrees) was decreased significantly when the lumbar spine was stabilized. In women the electromyographic activity (percentage of MVIC) in gluteus medius, external oblique, and rectus abdominis was significantly higher than that observed in men. CONCLUSIONS: With lumbar stabilization, the gluteus medius and internal oblique activity was increased significantly, and the quadratus lumborum activity was decreased significantly, causing reduced lateral pelvic tilt in a sidelying position. These results suggest that hip abduction with lumbar stabilization is useful in excluding substitution by the quadratus lumborum.     

Wheelchair configuration and postural alignment in persons with spinal cord injury

OBJECTIVE: To determine whether postural alignment and shoulder flexion range differ for persons with spinal cord injury (SCI) seated in wheelchairs with standard configurations versus wheelchairs with posterior seat inclination and a low backrest set perpendicular to the floor. DESIGN: Prospective repeated-measures study. SETTING: Outpatient SCI clinic. PARTICIPANTS: Fourteen subjects with C6-T10 motor-complete SCI. INTERVENTIONS: Subjects sat in 3 manual wheelchairs: standard setup E&J Premier (S1), standard setup Quickie Breezy (S2), and test configuration Quickie TNT (T) with posterior seat inclination and a low backrest set perpendicular to the floor. MAIN OUTCOME MEASURES: Shoulder and neck alignment and pelvic tilt were determined from sagittal plane digital photographs at rest and with maximal vertical reach. RESULTS: At rest, T produced less shoulder protraction than either standard configuration (difference between the mean values, S1: 1.6 cm, P=.048; S2: 1.2 cm, P=.013). S1 and S2 showed a greater head-forward position than T (differences between the mean values, S1: 6.5 degrees, P=.008; S2: 6.3 degrees, P=.013). T allowed greater humeral flexion than S2 (difference between the mean values: 3.7 degrees, P=.036) and greater vertical reach above the seat plane than either conventional configuration (differences between the mean values, S1: 4.7 cm, P=.005; S2: 4.1cm, P=.002). The indirect pelvic tilt measurement showed a trend (P=.06) toward greater posterior pelvic tilt with S1 and S2. CONCLUSION: The alternate configuration produces more vertical postural alignment and greater reach ability versus the standard factory setup wheelchairs.     

The use of pressure mapping for seating posture characterisation in children with cerebral palsy

Purpose.?To investigate the feasibility of using pressure mapping for the characterisation of the seated posture of children with cerebral palsy (CP).

Method.?Analysis of pressure mapping readings and video of children seated in a seating system during two assessments: The first assessment involved the pressure mapping of non-disabled children during a standardised protocol, and the second one involved the pressure mapping of children with CP performing daily life activities.

Results.?It was possible to detect periods of activity of the children from pressure readings using the mean variation of pressure. Additionally, several parameters stemming from pressure readings were shown to be successful in assessing the posture of the children. The centre of pressure when positioned relative to the ischial tuberosities, allowed for recognition of ‘adverse postures’ involving pelvic obliquity/medio-lateral trunk flexion or antero-posterior pelvic tilt/trunk flexion-extension, as deviations from the centre point. The angle between the principal axis of the sensors' pressure and the medio-lateral axis of the seat was also proposed to characterise pelvic transverse rotation but could not be tested with the actual protocol.

Conclusions.?Pressure monitoring can be used to assess qualitatively and quantitatively sitting posture of children with CP.     

Reduced hip extension in the elderly: dynamic or postural?

OBJECTIVE: To test the hypothesis that reduced hip extension and increased anterior pelvic tilt in the elderly are dynamic gait phenomena that do not occur during normal standing posture. DESIGN: Experimental. SETTING: Gait laboratory. PARTICIPANTS: Twenty-five older adult subjects (mean age +/- standard deviation, 71+/-5 y) and 25 young adult subjects (mean age, 26+/-5 y). INTERVENTION: Subjects were observed during standing and walking at self-determined comfortable, slow, and fast walking speeds. Positions and kinematics of the pelvis and lower extremities were measured using a 3-dimensional video-based motion analysis system. MAIN OUTCOME MEASURES: Peak hip extension and anterior pelvic tilt. RESULTS: There were no statistically significant differences between the older and young adult groups during standing with respect to either hip extension (3 degrees +/-5 degrees vs 1 degrees +/-6 degrees) or anterior pelvic tilt (11 degrees +/-5 degrees vs 10 degrees +/-5 degrees). On the other hand, at comfortable walking speeds, the older adult group had reduced peak hip extension (7 degrees +/-6 degrees vs 11 degrees +/-6 degrees , P<.05) and increased anterior pelvic tilt (15 degrees +/-5 degrees vs 11 degrees +/-5 degrees) compared with the young adult group. At fast walking speeds, peak hip extension was significantly reduced in the older adult group than in the young adult group (9 degrees +/-6 degrees vs 14 degrees +/-6 degrees , P<.05), but there was no significant difference at slow walking speeds (6 degrees +/-6 degrees vs 9 degrees +/-5 degrees ). CONCLUSIONS: Age-related changes in gait defined by reduced peak hip extension and increased pelvic tilt are dynamic rather than standing postural characteristics.     

Correlations among pelvic positions and differences in lower extremity joint angles during walking in female university students

[Purpose] This study aimed to identify correlations among pelvic positions and differences in lower extremity joint angles during walking in female university students. [Subjects] Thirty female university students were enrolled and their pelvic positions and differences in lower extremity joint angles were measured. [Methods] Pelvic position, pelvic torsion, and pelvic rotation were assessed using the BackMapper. In addition, motion analysis was performed to derive differences between left and right flexion, abduction, and external rotation ranges of hip joints; flexion, abduction, and external rotation ranges of knee joints; and dorsiflexion, inversion, and abduction ranges of ankle joints, according to X, Y, and Z-axes. [Results] Pelvic position was found to be positively correlated with differences between left and right hip flexion (r=0.51), hip abduction (r=0.62), knee flexion (r=0.45), knee abduction (r=0.42), and ankle inversion (r=0.38). In addition, the difference between left and right hip abduction showed a positive correlation with difference between left and right ankle dorsiflexion (r=0.64). Moreover, differences between left and right knee flexion exhibited positive correlations with differences between left and right knee abduction (r=0.41) and ankle inversion (r=0.45). [Conclusion] Bilateral pelvic tilt angles are important as they lead to bilateral differences in lower extremity joint angles during walking.Key words: Pelvic position, Lower extremity joint angle, Walking     

Effects of the posterior pelvic tilt sitting posture on thoracic morphology and respiratory function

[Purpose] We investigated how differences in pelvic angle in the posterior pelvic tilt sitting posture simultaneously affect the thoracic morphology and the respiratory function. [Participants and Methods] The participants were 18 healthy young males. We positioned the pelvis at 0°, 10°, 20°, and 30° of posterior tilt, following which the thoracic expansion volume ratio, thoracic spine tilt angle, and respiratory function were measured. We calculated the thoracic volume and thoracic spine tilt angle by measuring the amount of displacement of reflective markers attached to the thoracic area using the Vicon MX 3D-analysis system. Respiratory function was measured by spirometry. [Results] The expansion volume ratio decreased significantly in response to 10–30° posterior pelvic tilt sitting at the mid-thorax and 30° posterior pelvic tilt sitting at the lowest thorax. The upper thoracic spine level showed a change in anterior tilt at 10–30° posterior pelvic tilt sitting, whereas the lower thoracic spine level showed a change in posterior tilt at 30° posterior pelvic tilt sitting. Respiratory function was significantly lower at 30° posterior pelvic tilt sitting than at 0° posterior pelvic tilt sitting. A positive correlation between thoracic expansion volume ratio and respiratory function was found at 30° posterior pelvic tilt sitting. [Conclusion] Changes in thoracic spine tilt angle due to posterior pelvic tilt sitting may restrict the expansion of thoracic motion during respiration, thereby affecting respiratory function.Key words: Posterior pelvic tilt sitting posture, Thoracic morphology, Respiratory function     

Effect of initial position on the muscle activity of the hip extensors and amount of pelvic tilt during prone hip extension

[Purpose] The aim of this study was to identify the effects of initial position of the hip joint with changes in the hip joint angle on the respective muscle activities of the bilateral erector spinae (ES), unilateral gluteus maximus (GM), and biceps femoris (BF) and the amount of pelvic anterior tilt during prone hip extension (PHE). [Subjects] Fifteen healthy volunteers were enrolled in this study. [Methods] The subjects performed PHE in three positions: neutral, 20°, and 45° flexed hip joint. The activities of the ES, GM, and BF were measured using surface electromyography, and kinematic values for pelvic anterior tilt were calculated using a motion capture system. [Results] There was a significant decrease in muscle activity of the contralateral ES at 45°, and an increase in the GM muscle activity and decrease in the BF muscle activity at 20°. The amount of pelvic anterior tilt was lower at 20°. [Conclusion] These results suggest that a hip flexion position of 20° would have an advantage over the other measured positions.Key words: Electromyography, Joint position, Prone hip extension     

Examination of the flexion relaxation phenomenon in erector spinae muscles during short duration slumped sitting

OBJECTIVE: The purpose of this study was to examine the myoelectric activity of the erector spinae muscles of the back in order to determine if the flexion relaxation phenomenon occurs in seated forward flexion or slumped postures. BACKGROUND: The flexion relaxation phenomenon during standing forward flexion is well documented. However, flexion relaxation in seated forward flexion has not been studied. It is possible that flexion relaxation could be linked with low back pain that some individuals experience during seated work. METHODS: Twenty-two healthy subjects (11 males, 11 females) participated in the study. Surface electromyography was used to measure the level of muscle activity at the thoracic and lumbar levels of the erector spinae muscles. An electromagnetic tracking device measured the three-dimensional movement of the lumbar spine. Five trials each of standing and seated forward flexion were performed. RESULTS: A slumped sitting posture yielded flexion relaxation of the thoracic erector spinae muscles, whereas the lumbar erector spinae muscle group remained at relatively constant activation levels regardless of seated posture. Thoracic erector spinae silence occurred at a smaller angle of lumbar flexion during sitting than the flexion relaxation angle observed during standing flexion relaxation. CONCLUSIONS: Since the myoelectric activity of the lumbar erector spinae did not increase, it is likely that the passive tissues of the vertebral column were loaded to support the moment at L4/L5. Ligaments contain a large number of free nerve endings which act as pain receptors and therefore could be a potential source of low back pain during seated work. RELEVANCE: Examination of flexion relaxation during seated postures may provide insight into the association between low back pain and seated work.     

不同检查者和不同检查工具对关节活动度检查的影响

目的观察不同检查者和不同检查工具对关节活动度(ROM)检查的影响。方法对104名健康青年人进行肩前屈、后伸、外展、内旋、外旋ROM测定,每位受试者接受2位检查者用通用量角器和方盘量角器检查,对比受试者主动活动与被动活动、左侧与右侧、同一检查者用通用量角器与方盘量角器的ROM值,以及不同检查者用通用量角器、方盘量角器的ROM值。结果无论用哪一种量角器,受试者主动ROM均小于被动ROM,有显著差异,但左右两侧ROM无显著差异。使用通用量角器和方盘量角器相比,肩前屈ROM无显著差异,肩后伸、外展、内旋、外旋ROM有显著差异。不同检查者用方盘量角器测量ROM值无显著差异,用通用量角器测量肩内旋ROM值无显著差异,肩前屈、后伸、内旋、外旋ROM值有显著差异。结论方盘量角器测量ROM的可重复性较高。为确保ROM检查结果的可比性,应由同一位检查者使用同一种检查工具对患者进行ROM检查。     

Influence of trunk flexion on hip and knee joint kinematics during a controlled drop landing

BACKGROUND: An erect posture and greater knee valgus during landing have been implicated as anterior cruciate ligament injury risk factors. While previous research suggests coupling of knee and hip kinematics, the influence of trunk positioning on lower extremity kinematics has yet to be determined. We hypothesized that greater trunk flexion during landing would result in greater knee and hip flexion and lesser knee valgus. Identification of a modifiable factor (e.g. trunk flexion) which positively influences kinematics of multiple lower extremity joints would be invaluable for anterior cruciate ligament injury prevention efforts. METHODS: Forty healthy individuals completed two drop landing tasks while knee, hip, and trunk kinematics were sampled. The first task constituted the natural/preferred landing strategy (Preferred), while in the second task, subjects actively flexed the trunk upon landing (Flexed). FINDINGS: Peak trunk flexion angle was 47 degrees greater for Flexed compared to Preferred (P<0.001), and was associated with increases in peak hip flexion angle of 31 degrees (P<0.001) and peak knee flexion angle of 22 degrees (P<0.001). INTERPRETATION: Active trunk flexion during landing produces concomitant increases in knee and hip flexion angles. A more flexed/less erect posture during landing is associated with a reduced anterior cruciate ligament injury risk. As such, incorporating greater trunk flexion as an integral component of anterior cruciate ligament injury prevention programs may be warranted.     

Intra- and intertester reliability and criterion validity of the parallelogram and universal goniometers for measuring maximum active knee flexion and extension of patients with knee restrictions

OBJECTIVE: To examine the intra- and intertester reliability of the universal goniometer (UG) and parallelogram goniometer (PG), and to assess the criterion validity of the same instruments on subjects with knee restrictions. DESIGN: Reliability and validation study. SETTING: Radiology department at university hospital. PARTICIPANTS: Sixty subjects (34 men, 26 women; mean age, 52yr) with various knee restrictions. INTERVENTIONS: Sixteen goniometric measurements were collected per patient by 2 physical therapists. Subjects were evaluated in knee flexion and knee extension positions. To serve as a gold standard, radiographs were taken in both positions. MAIN OUTCOME MEASURES: Active knee flexion and knee extension on 2 goniometers, radiographs. Maximum active range of motion (AROM). RESULTS: The UG intratester reliability (intraclass correlation coefficients [ICCs]) was .997 in flexion and .972 to .985 in extension. The results were also high with the PG (ICC =.996,.953-.955) for flexion and extension, respectively. The intertester reliability was high for flexion (ICC =.977-.982) and for extension (ICC =.893-.926) when using the UG. For the PG, ICC results ranged from .959 to .970 for flexion and from .856 to .898 for extension. Criterion validity (r) varied from .975 to .987 for flexion and from .390 to .442 for extension with the UG, and from .976 to .985 for flexion and .423 to .514 for extension with the PG. CONCLUSION: Intra- and intertester reliability were high for both goniometers. The results for the criterion validity varied. Our study also revealed that it is preferable to use goniometry rather than visual estimations when measuring AROM. It is recommended that the same therapist take all the measurements when assessing AROM for UG and PG goniometric measurements on patients with knee restrictions.