Reliability and validity of videotaped functional performance tests in ACL‐injured subjects

Background and Purpose . In clinical practice, visual observation is often used to determine functional impairment and to evaluate treatment following a knee injury. The aim of this study was to evaluate the reliability and validity of observational assessments of knee movement pattern quality during five functional tests in subjects with an anterior cruciate ligament (ACL) injury. Method . Twelve ACL‐injured men, mean age 40 years, were video filmed before and after 12 weeks of knee‐specific training when performing five different functional tests: walking, knee bending, step activity, crossover hop on one leg and one‐leg hop. The videos were observed by four physiotherapists, and the knee movement pattern quality, a feature of the loading strategy of the lower extremity, was scored on an 11‐point rating scale. To assess the criterion validity, the observational rating was correlated with the maximum knee flexion angle in landing during the crossover hop determined by a three‐dimensional motion analysis system (VICON). Results . Inter‐observer agreement between the four physiotherapists was moderate to good, ICC_1,2 0.57–0.76 for the four test situations. Fair to good correlations were obtained between the observers' assessment and knee flexion angle, r = 0.37–0.61. The crossover hop test or one‐leg hop test was ranked as the most useful test in 172 of 192 occasions (90%) when assessing knee function. Conclusion . The moderate to good inter‐observer reliability and the moderate criterion validity found indicate that the knee movement pattern quality in ACL‐injured subjects can be determined by visual observation of more demanding functional tests such as crossover hop on one leg and one‐leg hop for distance. Copyright © 2008 John Wiley & Sons, Ltd.     

FUNCTIONAL PERFORMANCE TESTING OF THE HIP IN ATHLETES: A SYSTEMATIC REVIEW FOR RELIABILITY AND VALIDITY

Purpose/Background:

The purpose of this study was to systematically review the literature for functional performance tests with evidence of reliability and validity that could be used for a young, athletic population with hip dysfunction.

Methods:

A search of PubMed and SPORTDiscus databases were performed to identify movement, balance, hop/jump, or agility functional performance tests from the current peer-reviewed literature used to assess function of the hip in young, athletic subjects.

Results:

The single-leg stance, deep squat, single-leg squat, and star excursion balance tests (SEBT) demonstrated evidence of validity and normative data for score interpretation. The single-leg stance test and SEBT have evidence of validity with association to hip abductor function. The deep squat test demonstrated evidence as a functional performance test for evaluating femoroacetabular impingement. Hop/Jump tests and agility tests have no reported evidence of reliability or validity in a population of subjects with hip pathology.

Conclusions:

Use of functional performance tests in the assessment of hip dysfunction has not been well established in the current literature. Diminished squat depth and provocation of pain during the single-leg balance test have been associated with patients diagnosed with FAI and gluteal tendinopathy, respectively. The SEBT and single-leg squat tests provided evidence of convergent validity through an analysis of kinematics and muscle function in normal subjects. Reliability of functional performance tests have not been established on patients with hip dysfunction. Further study is needed to establish reliability and validity of functional performance tests that can be used in a young, athletic population with hip dysfunction.

Level of Evidence:

2b (Systematic Review of Literature)     

Improvements in kinematics,muscle activity and pain during functional tasks in females with patellofemoral pain following a single patterned electrical stimulation treatment

BackgroundIndividuals with patellofemoral pain present with altered hip muscle activation, faulty movement patterns, and pain during functional tasks. Examining new treatment options to address these impairments may better treat those with patellofemoral pain. The purpose of this study was to determine if patterned electrical stimulation to the lower extremity affects muscle activity, movement patterns, and pain following a single treatment.MethodsFifteen females with patellofemoral pain were randomized to receive a single 15-minute treatment of either a patterned electrical neuromuscular stimulation or a sham. Peak kinematics of the knee, hip, and trunk, electromyography and pain were examined pre and post-intervention during a single leg squat and lateral step-down task. Group means and pre/post reduced kinematic values were also plotted during the entire task with 90% confidence intervals to identify differences in movement strategies.FindingsNo baseline differences were found in peak kinematics between groups. No pre to post-intervention differences in peak knee, hip and trunk kinematics were found, however differences were seen when the quality of movement across the entire tasks was assessed. The electrical stimulation group had improved knee flexion and hip abduction during the lateral step-down. A significant improvement in gluteus medius activation following patterned electrical neuromuscular stimulation occurred during the step-down (P = 0.039). Significant pain improvements were also seen in both the single leg squat (P = 0.025) and lateral step-down (P = 0.006).InterpretationA single treatment of patterned electrical neuromuscular stimulation improved muscle activation, lower extremity kinematics during functional tasks, and pain.     

Is there a correlation in frontal plane knee kinematics between running and performing a single leg squat in runners with patellofemoral pain syndrome and asymptomatic runners?

BackgroundKnee kinematics when running, specifically knee valgus, have been linked to patellofemoral pain syndrome. Assessing running biomechanics requires skill, equipment and time. Clinically, the single leg squat is used to make inferences about knee kinematics during running. No evidence supports this practice.MethodsSixteen asymptomatic runners and sixteen runners with patellofemoral pain syndrome were recruited. Asymptomatic runners were sub-divided by dominant and non-dominant leg and runners with patellofemoral pain syndrome by painful and non-painful leg. This gave four groups. Participants were videoed performing single leg squats and running on a treadmill. Frontal plane knee kinematics were calculated using the frontal plane projection angle. Correlation in frontal plane projection angle between running and single leg squat were calculated using Pearson's correlation coefficient. Differences in frontal plane projection angle between groups for running and single leg squat were calculated using multiple independent t-tests with Bonferroni correction.FindingsCorrelation in frontal plane projection angle between running and the single leg squat was not statistically significant for the painful leg group (p = 0.19) but was for the remaining groups (p < 0.05). There was no statistically significant difference in frontal plane projection angle between the four groups when running. Single leg squat frontal plane projection angle was significantly larger for the painful leg group (10.3°) than the dominant leg (−0.2° (p = 0.003)) and non-dominant leg (−0.4° (p = 0.004)) in the asymptomatic runners group.InterpretationThe single leg squat cannot be used to make inferences about frontal plane knee kinematics in running gait in patellofemoral pain syndrome sufferers.     

NOT ALL SINGLE LEG SQUATS ARE EQUAL: A BIOMECHANICAL COMPARISON OF THREE VARIATIONS

Background

The single leg squat (SLS) is a functional task used by practitioners to evaluate and treat multiple pathologies of the lower extremity. Variations of the SLS may have different neuromuscular and biomechanical demands. The effect of altering the non-stance leg position during the SLS on trunk, pelvic, and lower extremity mechanics has not been reported.

Purpose

The purpose of this study was to compare trunk, pelvic, hip, knee, and ankle kinematics and hip, knee, and ankle kinetics of three variations of the SLS using different non-stance leg positions: SLS-Front, SLS-Middle, and SLS-Back.

Methods

Sixteen healthy women performed the three SLS tasks while data were collected using a motion capture system and force plates. Joint mechanics in the sagittal, frontal, and transverse planes were compared for the SLS tasks using a separate repeated-measures analysis of variance (ANOVA) for each variable at two analysis points: peak knee flexion (PKF) and 60 ° of knee flexion (60KF).

Results

Different non-stance leg positions during the SLS resulted in distinct movement patterns and moments at the trunk, pelvis, and lower extremity. At PKF, SLS-Back exhibited the greatest kinematic differences (p < 0.05) from SLS-Front and SLS-Middle with greater ipsilateral trunk flexion, pelvic anterior tilt and drop, hip flexion and adduction, and external rotation as well as less knee flexion and abduction. SLS-Back also showed the greatest kinetic differences (p < 0.05) from SLS-Front and SLS-Middle with greater hip external rotator moment and knee extensor moment as well as less hip extensor moment and knee adductor moment at PKF. At 60KF, the findings were similar except at the knee.

Conclusion

The mechanics of the trunk, pelvis, and lower extremity during the SLS were affected by the position of the non-stance leg in healthy females. Practitioners can use these findings to distinguish between SLS variations and to select the appropriate SLS for assessment and rehabilitation.

Level of Evidence

3     

Closed-chain exercise after simultaneous bilateral knee replacement surgery: A case report

ABSTRACT

The purpose of this case report was to present a method for assessing entire lower extremity performance and describe a Medical Exercise Therapy (MET) training program early after simultaneous bilateral total knee replacement (TKR). We also documented perceived function, mobility, and weight-bearing ability during functional tasks. The patient was a 50-year-old male who underwent a simultaneous bilateral procedure and began physical therapy (PT) 16 days postsurgery. Lower extremity performance (weight, repetitions, and load*volume) was assessed weekly using a one-legged horizontal press. Perceived physical abilities, mobility, and body weight placed over each limb during a sit to stand and a squat at two different flexion angles were assessed. At discharge load*volume for the weakest limb was 87% of the strongest side. At discharge, sit-to-stand, and 30 and 60 degree squat asymmetry ranged from 4% to 6%. Perceived abilities and mobility improved from initial visit to discharge. The patient was able to tolerate the closed-chain assessment of lower extremity performance and MET training program early after surgery. The patient made improvements in all functional tests and more importantly maintained a fairly equal distribution of body weight over both limbs during functional activities.     

Muscle power is an important measure to detect deficits in muscle function in hip osteoarthritis: a cross-sectional study

Purpose: To investigate between-leg differences in hip and thigh muscle strength and leg extensor power in patients with unilateral hip osteoarthritis. Further, to compare between-leg differences in knee extensor strength and leg extensor power between patients and healthy peers.

Methods: Seventy-two patients (60–87 years) with radiographic and symptomatic hip osteoarthritis not awaiting hip replacement and 35 healthy peers (63–82 years) were included. Hip and thigh muscle strength and leg extensor power were measured in patients and knee extensor strength and leg extensor power in healthy.

Results: The symptomatic extremity in patients was significantly (p?t-test) weaker compared with the non-symptomatic extremity for five hip muscles (8–17%), knee extensors (11%) and leg extensor power (19%). Healthy older adults had asymmetry in knee extensor strength (6%, p?Conclusions: Patients had generalized weakening of the affected lower extremity and numerically the largest asymmetry was evident for leg extensor power. In contrast, healthy peers had no asymmetry in leg extensor power. These results indicate that exercise interventions focusing on improving leg extensor power of the symptomatic lower extremity and reducing asymmetry may be beneficial for patients with hip osteoarthritis.

• Implications for Rehabilitation

• Even in patients with mild symptoms not awaiting hip replacement a generalized muscle weakening of the symptomatic lower extremity seems to be present.

• Between-leg differences in leg extensor power (force?×?velocity) appears to be relatively large (19%) in patients with unilateral hip osteoarthritis in contrast to healthy peers who show no asymmetry.

• Compared to muscle strength the relationship between functional performance and leg extensor power seems to be stronger, and more strongly related to power of the symptomatic lower extremity.

• Our results indicate that exercise interventions focusing on improving leg extensor power of the symptomatic lower extremity and reducing asymmetry may be beneficial for patients with mild symptoms not awaiting hip replacement.

     

THE INFLUENCE OF CORE MUSCULATURE ENGAGEMENT ON HIP AND KNEE KINEMATICS IN WOMEN DURING A SINGLE LEG SQUAT

Purpose/Background:

Excessive frontal plane motion and valgus torques have been linked to knee injuries, particularly in women. Studies have investigated the role of lower extremity musculature, yet few have studied the activation of trunk or “core” musculature on hip and knee kinematics. Therefore, this study evaluated the influence of intentional core engagement on hip and knee kinematics during a single leg squat.

Methods:

Participants (n = 14) performed a single leg squat from a 6 inch step under 2 conditions: core intentionally engaged (CORE) and no intentional core engagement (NOCORE). Participants were also evaluated for core activation ability using Sahrmann''s model, and the resulting scores were used to divide participants into low (LOWCORE) and high scoring (HIGHCORE) groups. All trials were captured using 3-D motion analysis, and data were normalized for height and time. Paired t-tests and repeated measures, mixed model MANOVAs were used to assess condition and group differences.

Results:

The CORE condition, compared to NOCORE, was characterized by smaller right [t(13) = 3.03, p = .01] and left [t(13) = 3.04, p = .01] hip frontal plane displacement and larger knee flexion range of motion [t(13) = 3.08, p = .009]. Subsequent MANOVAs and follow-up analyses revealed that: (1) the CORE condition demonstrated smaller right and left hip medial-lateral displacement in the LOWCORE group (p = .001), but not in the HIGHCORE group; (2) the CORE condition showed larger overall knee flexion range of motion across LOWCORE and HIGHCORE groups (p = .021); and (3) the HIGHCORE group exhibited less knee varus range of motion across CORE and NOCORE conditions (p = .028).

Conclusions:

Intentional core activation influenced hip and knee kinematics during single leg squats, with greater positive effect noted in the LOWCORE group. These findings may have implications for preventing and rehabilitating knee injuries among women.

Level of Evidence:

2B, Cohort laboratory study, mixed model design     

Assessment of texture discrimination ability at the sole of the foot in subjects with chronic stroke compared with young and elderly subjects with no neurological deficits: a reliability and validity study

Purpose: To examine validity and test–retest reliability of a sensory test developed to evaluate ability of elderly subjects with/out a stroke to discriminate between textures with the sole of their foot.

Methods: Subjects poststroke, old adults and young subjects were tested twice. Twelve materials relevant to foot function (e.g., gravel, sand) were used. Blindfolded subjects were requested to discriminate with the sole of each foot one outstanding texture among three textures presented in each of 12 subtests. ANOVA, ICC and Bland–Altman tests were used to determine group/leg differences and test-retest reliability.

Results: Discrimination ability of the involved lower extremity poststroke is significantly reduced. Ability in individuals with no neurological impairment is age related. Good test–retest (ICC?=?0.81) reliability was demonstrated for the impaired foot of subjects poststroke. The 95% repeatability ranges were age related with the highest range demonstrated for the involved foot poststroke. A significant fair negative correlation was demonstrated between texture discrimination ability and tactile detection threshold measured by Semmes–Weinstein monofilaments for the involved foot in poststroke subjects.

Conclusion: This newly developed assessment tool demonstrates concurrent and known-groups validity and is reliable for determining texture discriminative ability of the foot in individuals post-stroke and in older adults with no neurological impairment.

• Implications for rehabilitation

• The texture discrimination test presented here is a valid and reliable tool, providing quantitative assessment of sensory function at the sole of the foot in older adults with no neurologic deficits and in subjects poststroke.

• Lower extremity texture discrimination test is easy to administer in the clinic and might suggest directions for individually tailored, lower extremity, sensory retraining protocols.

     

Lower limb kinematics of single-leg squat performance in patients with anterior cruciate ligament deficiency

[Purpose] This study investigated the parameters that characterize the knee, hip, and pelvic kinematics during a single-leg squat in preoperative anterior cruciate ligament rupture injury. [Participants and Methods] Overall, 15 patients with unilateral anterior cruciate ligament deficiency were enrolled in this study. For each single-leg squat, data from two-dimensional video cameras and three-dimensional motion analysis were collected. Measurement indices included the articular angles of the knee, hip, and trunk. The anterior cruciate ligament-injured leg was compared with the uninjured leg. [Results] The maximum knee valgus and flexion angles during a single-leg squat were smaller in the injured leg than in the uninjured leg. During the single-leg squat, the effect of “compensatory mechanisms” appeared as knee valgus and flexion movements. In particular, the knee valgus angle decreased in the anterior cruciate ligament-injured leg compared to that in the uninjured leg. [Conclusion] This phenomenon suggests that it is possible to utilize recurrence prevention training for anterior cruciate ligament injury.Key words: Knee dynamic valgus, Three-dimensional kinematic analysis, Compensatory mechanisms     

Concurrent validity and reliability of clinical evaluation of the single leg squat

This study determined reliability and concurrent validity of measurements of the single leg squat made by novice examiners. Twelve video recordings of individuals performing a single leg squat were evaluated by six student physical therapists. Students assessed movement quality on an ordinal scale and manually measured frontal plane knee movement quantity on a video monitor. Inter- and intrarater reliability of ordinal scale ratings were determined via quadratically weighted kappa. Inter- and intrarater reliability of frontal plane knee measures were determined through intraclass correlation coefficient models 2,k and 3,k (k?=?3 ratings), respectively. Concurrent validity of frontal plane knee measures was examined by comparison with Vicon-Peak motion-tracking system measures via Bland-Altman scatterplots. Ordinal scale measures displayed intrarater reliability ranging from 0.38 to 0.94 and interrater reliability of 0.68 (0.46–0.87). Intrarater reliability of frontal plane knee measures ranged from 0.88 to 0.98 and interrater reliability of 0.99 (0.97–1.00). Difference scores between student and computer-generated measures of frontal plane knee movement were significantly different as determined through Bland-Altman scatterplots and calculation of the upper and lower limits of agreement.     

Concurrent validity and reliability of clinical evaluation of the single leg squat

This study determined reliability and concurrent validity of measurements of the single leg squat made by novice examiners. Twelve video recordings of individuals performing a single leg squat were evaluated by six student physical therapists. Students assessed movement quality on an ordinal scale and manually measured frontal plane knee movement quantity on a video monitor. Inter- and intrarater reliability of ordinal scale ratings were determined via quadratically weighted kappa. Inter- and intrarater reliability of frontal plane knee measures were determined through intraclass correlation coefficient models 2,k and 3,k (k?=?3 ratings), respectively. Concurrent validity of frontal plane knee measures was examined by comparison with Vicon-Peak motion-tracking system measures via Bland-Altman scatterplots. Ordinal scale measures displayed intrarater reliability ranging from 0.38 to 0.94 and interrater reliability of 0.68 (0.46-0.87). Intrarater reliability of frontal plane knee measures ranged from 0.88 to 0.98 and interrater reliability of 0.99 (0.97-1.00). Difference scores between student and computer-generated measures of frontal plane knee movement were significantly different as determined through Bland-Altman scatterplots and calculation of the upper and lower limits of agreement.     

Reliability and diagnostic validity of the slump knee bend neurodynamic test for upper/mid lumbar nerve root compression: a pilot study

Objectives

It has been proposed that neurodynamic examination can assist differential diagnosis of upper/mid lumbar nerve root compression; however, the diagnostic validity of many of these tests has yet to be established. This pilot study aimed to establish the diagnostic validity of the slump knee bend neurodynamic test for upper/mid lumbar nerve root compression in subjects with suspected lumbosacral radicular pain.

Design

Two independent examiners performed the slump knee bend test on subjects with radicular leg pain. Inter-tester reliability was calculated using the kappa coefficient. Slump knee bend test results were compared with magnetic resonance imaging findings, and diagnostic accuracy measures were calculated including sensitivity, specificity, predictive values and likelihood ratios.

Setting

Orthopaedic spinal clinic, secondary care.

Participants

Sixteen patients with radicular leg pain.

Results

All four subjects with mid lumbar nerve root compression on magnetic resonance imaging were correctly identified with the slump knee bend test; however, it was falsely positive in two individuals without the condition. Inter-tester reliability for the slump knee bend test using the kappa coefficient was 0.71 (95% confidence interval 0.33 to 1.0). Diagnostic validity calculations for the slump knee bend test (95% confidence intervals) were: sensitivity, 100% (40 to 100%); specificity, 83% (52 to 98%); positive predictive value, 67% (22 to 96%); negative predictive value, 100% (69 to 100%); positive likelihood ratio, 6.0 (1.58 to 19.4); and negative likelihood ratio, 0 (0 to 0.6).

Conclusions

Results indicate good inter-tester reliability and suggest that the slump knee bend test has potential to be a useful clinical test for identifying patients with mid lumbar nerve root compression. Further investigation is needed on larger numbers of patients to confirm these findings.     

Varus alignment after total knee arthroplasty results in greater axial rotation during deep knee bend activity

BackgroundsThe correlation between in vivo knee kinematics and alignment has not been fully elucidated. Recently, similar or better clinical outcomes have been reported by restoration of mild varus alignment after total knee arthroplasty for preoperative varus knees. The aim of this study was to evaluate the effect of postoperative alignment on knee kinematics during a deep knee bend activity.MethodsIn vivo knee kinematics of 36 knees (25 patients) implanted with tri-condylar total knee arthroplasty were analyzed with a three dimensional model fitting approach using fluoroscopy. Under fluoroscopic surveillance, individual video frames were digitized at 30° increments from full extension to maximum flexion. Postoperative coronal and sagittal alignments were assessed using radiographs, and rotational alignment was assessed with computed tomography. Pearson correlation coefficients were calculated to determine the correlations between the alignment data and kinematic factors.FindingsCorrelation analysis showed that coronal alignment was significantly correlated with knee kinematics. The varus alignment of the limb and tibial component led to a greater axial rotation from full extension to maximum flexion and more rotated position in the mid to deep flexion range. Neither the rotational alignment of the femoral nor tibial components showed significant correlation with axial rotation from full extension to maximum flexion.InterpretationVarus alignment resulted in greater axial rotation, which could represent near-normal knee kinematics. The current study can be a kinematic rationale reporting similar or better clinical and functional outcomes for the total knee arthroplasty with residual varus alignment.     

EFFECTS OF A MOVEMENT TRAINING PROGRAM ON HIP AND KNEE JOINT FRONTAL PLANE RUNNING MECHANICS

Background/Purpose:

Frontal plane running mechanics may contribute to the etiology or exacerbation of common running related injuries. Hip strengthening alone may not change frontal plane hip and knee joint running mechanics. The purpose of the current study was to evaluate whether a training program including visual, verbal, and tactile feedback affects hip and knee joint frontal plane running mechanics among females with evidence of altered weight bearing kinematics.

Methods:

The knee frontal plane projection angle of 69 apparently healthy females was determined during a single leg squat. The twenty females from this larger sample who exhibited the most acute frontal plane projection angle (medial knee position) during this activity were chosen to participate in this study (age = 20 ± 1.6 years, height = 167.9 ± 6.0 cm, mass = 63.2 ± 8.3 kg, Tegner Activity Rating mode = 7.0). Participants engaged in a 4‐week movement training program using guided practice during weight bearing exercises with visual, verbal, and tactile feedback regarding lower extremity alignment. Paired t‐tests were used to compare frontal plane knee and hip joint angles and moments before and after the training program.

Results:

After training, internal hip and knee abduction moments during running decreased by 23% (P=0.007) and 29% (P=0.033) respectively. Knee adduction and abduction excursion decreased by 2.1° (P = 0.050) and 2.7° (P=0.008) respectively, suggesting that less frontal plane movement of the knee occurred during running after training. Peak knee abduction angle decreased 1.8° after training (P=0.051) although this was not statistically significant. Contralateral peak pelvic drop, pelvic drop excursion, peak hip adduction angle, hip adduction excursion, and peak knee adduction angle were unchanged following training.

Conclusions:

A four week movement training program may reduce frontal plane hip and knee joint mechanics thought to contribute to the etiology and exacerbation of some running related injuries.

Level of Evidence:

Level 4     

OBSERVER RATING VERSUS THREE‐DIMENSIONAL MOTION ANALYSIS OF LOWER EXTREMITY KINEMATICS DURING FUNCTIONAL SCREENING TESTS: A SYSTEMATIC REVIEW

Background

Functional assessments are conducted in both clinical and athletic settings in an attempt to identify those individuals who exhibit movement patterns that may increase their risk of non‐contact injury. In place of highly sophisticated three‐dimensional motion analysis, functional testing can be completed through observation.

Hypothesis/purpose

To evaluate the validity of movement observation assessments by summarizing the results of articles comparing human observation in real‐time or video play‐back and three‐dimensional motion analysis of lower extremity kinematics during functional screening tests.

Study Design

Systematic review

Methods

A computerized systematic search was conducted through Medline, SPORTSdiscus, Scopus, Cinhal, and Cochrane health databases between February and April of 2014. Validity studies comparing human observation (real‐time or video play‐back) to three‐dimensional motion analysis of functional tasks were selected. Only studies comprising uninjured, healthy subjects conducting lower extremity functional assessments were appropriate for review. Eligible observers were certified health practitioners or qualified members of sports and athletic training teams that conduct athlete screening. The Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS‐2) was used to appraise the literature. Results are presented in terms of functional tasks.

Results

Six studies met the inclusion criteria. Across these studies, two‐legged squats, single‐leg squats, drop‐jumps, and running and cutting manoeuvres were the functional tasks analysed. When compared to three‐dimensional motion analysis, observer ratings of lower extremity kinematics, such as knee position in relation to the foot, demonstrated mixed results. Single‐leg squats achieved target sensitivity values (≥ 80%) but not specificity values (≥ 50%>%). Drop‐jump task agreement ranged from poor (< 50%) to excellent (> 80%). Two‐legged squats achieved 88% sensitivity and 85% specificity. Mean underestimations as large as 198 (peak knee flexion) were found in the results of those assessing running and side‐step cutting manoeuvres. Variables such as the speed of movement, the methods of rating, the profiles of participants and the experience levels of observers may have influenced the outcomes of functional testing.

Limitations

The small number of studies used limits generalizability. Furthermore, this review used two dimensional video‐playback for the majority of observations. If the movements had been rated in real‐time three dimensional video, the results may have been different.

Conclusions

Slower, speed controlled movements using dichotomous ratings reach target sensitivity and demonstrate higher overall levels of agreement. As a result, their utilization in functional screening is advocated.

Level of Evidence

1A     

VALIDITY OF AN MRI-COMPATIBLE MOTION CAPTURE SYSTEM FOR USE WITH LOWER EXTREMITY NEUROIMAGING PARADIGMS

Background:Emergent linkages between musculoskeletal injury and the nervous system have increased interest to evaluate brain activity during functional movements associated with injury risk. Functional magnetic resonance imaging (fMRI) is a sophisticated modality that can be used to study brain activity during functional sensorimotor control tasks. However, technical limitations have precluded the precise quantification of lower-extremity joint kinematics during active brain scanning. The purpose of this study was to determine the validity of a new, MRI-compatible motion tracking system relative to a traditional multi-camera 3D motion capture system for measuring lower extremity joint kinematics.Methods:Fifteen subjects (9 females, 6 males) performed knee flexion-extension and leg press movements against guided resistance while laying supine. Motion tracking data were collected simultaneously using the MRI-compatible and traditional multi-camera 3D motion systems. Participants’ sagittal and frontal plane knee angles were calculated from data acquired by both multi-camera systems. Resultant range of angular movement in both measurement planes were compared between both systems. Instrument agreement was assessed using Bland-Altman plots and intraclass correlation coefficients (ICC).Results:The system demonstrated excellent validity in the sagittal plane (ICCs>0.99) and good to excellent validity in the frontal plane (0.84 < ICCs < 0.92). Mean differences between corresponding range of angular movement measurements ranged from 0.186 ° to 0.295 °.Conclusions:The present data indicate that this new, MRI-compatible system is valid for measuring lower extremity movements when compared to the gold standard 3D motion analysis system. As there is growing interest regarding the neural substrates of lower extremity movement, particularly in relation to injury and pathology, this system can now be integrated into neuroimaging paradigms to investigate movement biomechanics and its relation to brain activity.Level of Evidence:3     

The psychometric properties of an Arabic numeric pain rating scale for measuring osteoarthritis knee pain

Purpose: The aims of this study were to translate the numeric rating scale (NRS) into Arabic and to evaluate the test–retest reliability and convergent validity of an Arabic Numeric Pain Rating Scale (ANPRS) for measuring pain in osteoarthritis (OA) of the knee.

Methods: The English version of the NRS was translated into Arabic as per the translation process guidelines for patient-rated outcome scales. One hundred twenty-one consecutive patients with OA of the knee who had experienced pain for more than 6 months were asked to report their pain levels on the ANPRS, visual analogue scale (VAS), and verbal rating scale (VRS). A second assessment was performed 48 h after the first to assess test–retest reliability. The test–retest reliability was calculated using the intraclass correlation coefficient (ICC_2,1). The convergent validity was assessed using Spearman rank correlation coefficient. In addition, the minimum detectable change (MDC) and standard error of measurement (SEM) were also assessed.

Results: The repeatability of ANPRS was good to excellent (ICC 0.89). The SEM and MDC were 0.71 and 1.96, respectively. Significant correlations were found with the VAS and VRS scores (p?<0.01).

Conclusions: The Arabic numeric pain rating scale is a valid and reliable scale for measuring pain levels in OA of the knee.

• Implications for Rehabilitation

• The Arabic Numeric Pain Rating Scale (ANPRS) is a reliable and valid instrument for measuring pain in osteoarthritis (OA) of the knee, with psychometric properties in agreement with other widely used scales.

• The ANPRS is well correlated with the VAS and NRS scores in patients with OA of the knee.

• The ANPRS appears to measure pain intensity similar to the VAS, NRS, and VRS and may provide additional advantages to Arab populations, as Arabic numbers are easily understood by this population.

     

THE RELATIONSHIP BETWEEN LOWER EXTREMITY CLOSED KINETIC CHAIN STRENGTH & SAGITTAL PLANE LANDING KINEMATICS IN FEMALE ATHLETES

Background:

Female athletes continue to injure their anterior cruciate ligaments at a greater rate than males in comparable sports. During landing activities, females exhibit several different kinematic and kinetic traits when compared to their male counterparts including decreased knee flexion angles as well as decreased lower extremity (LE) strength. While open kinetic chain strength measures have not been related to landing kinematics, given the closer replication of movement patterns that occur during closed kinetic chain (CKC) activity, it is possible that lower extremity strength if measured in this fashion will be related to landing kinematics.

Purpose:

To determine if unilateral isometric CKC lower extremity (LE) strength was related to sagittal plane tibiofemoral kinematics during a single leg landing task in competitive female athletes. We hypothesized females who demonstrated lesser CKC LE strength would exhibit decreased sagittal plane angles during landing.

Methods:

20 competitive female athletes (age = 16.0 ± 1.8 yrs; height = 166.5 ± 8.3 cm; weight = 59.7 ± 10.2 kg) completed CKC LE strength testing followed by 5 unilateral drop landings on the dominant LE during one test session at an outpatient physical therapy clinic. Closed kinetic chain LE strength was measured on a computerized leg press with an integrated load cell while sagittal plane tibiofemoral kinematics were quantified with an electrogoniometer.

Results:

No significant relationships between absolute or normalized isometric CKC strength and sagittal plane landing kinematics were identified.

Conclusions:

Closed kinetic chain lower extremity isometric strength tested at 25 degrees of knee flexion is not related to sagittal plane landing kinematics in adolescent competitive female athletes.Levels of Evidence: Analytic, Observational     

Frontal and transverse plane hip kinematics and gluteus maximus recruitment correlate with frontal plane knee kinematics during single-leg squat tests in women

Background

Hip muscle dysfunction may be associated with knee valgus that contributes to problems like patellofemoral pain syndrome. The purpose of this study was to (1) compare knee and hip kinematics and hip muscle strength and recruitment between “good” and “poor” performers on a single-leg squat test developed to assess hip muscle dysfunction and (2) examine relationships between hip muscle strength, recruitment and frontal plane knee kinematics to see which variables correlated with knee valgus during the test.

Methods

Forty-one active women classified via visual rating as “good” or “poor” performers on the test participated. Participants completed 5-repetition single-leg squat tests. Isometric hip extension and abduction strength, gluteus maximus and gluteus medius recruitment, and 3-dimensional hip and knee kinematics during the test were compared between groups and examined for their association with frontal plane knee motion.

Findings

“Poor” performers completed the test with more hip adduction (mean difference = 7.6°) and flexion (mean difference = 6.3°) than “good” performers. No differences in knee kinematics, hip strength or hip muscle recruitment occurred. However, the secondary findings indicated that increased medial hip rotation (partial r = 0.94) and adduction (partial r = 0.42) and decreased gluteus maximus recruitment (partial r = 0.35) correlated with increased knee valgus.

Interpretation

Whereas hip muscle function and knee kinematics did not differ between groups as we'd hypothesized, frontal plane knee motion correlated with transverse and frontal plane hip motions and with gluteus maximus recruitment. Gluteus maximus recruitment may modulate frontal plane knee kinematics during single-leg squats.