Hip Flexion Range Of Motion Research Articles

In Vivo Ultrasound Measurement of Posterior Femoral Glide During Hip Joint Mobilization in Healthy College Students

Descriptive study. To measure femoral translational glide in vivo during posterior hip joint mobilization and to interpret data in the context of the normal arthrokinematic glide necessary for hip flexion. Joint play, or translational glide available at a joint, is largely influenced by the geometry of the articular surfaces. The high degree of congruence between the articular surfaces at the hip and the substantial arc of concavity of the acetabulum suggests that the amount of translational glide available at the hip should be very small. Twenty subjects received manual posteriorly directed hip mobilization at a force equal to 50% of their body weight, while concurrent ultrasound imaging of the joint was performed. Images were captured before and during application of the target mobilization force. Femoroacetabular distance for each image was measured, and the average of the 3 greatest differences between corresponding before/during mobilization values represented the translational glide produced. The amplitude of arthrokinematic glide (tangential glide) was calculated using the measured femoral head radius and hip flexion passive range of motion for each subject. The average posterior femoral translational glide was 2.0 mm (range, 0.8-4.2 mm). The average calculated tangential glide required for hip flexion passive range of motion was 53.8 mm (range, 43.2-64.8 mm). The average translational glide as a percentage of tangential glide was 3.8% (range, 1.5%-7.9%). Translational glides at the hip are small, particularly in the context of the amplitude of glide necessary for normal hip flexion range of motion.

Postural taping applied to the low back influences kinematics and EMG activity during patient transfer in physical therapists with chronic low back pain

We examined the influence of the application of postural taping on the kinematics of the lumbo–pelvic–hip complex, electromyographic (EMG) activity of back extensor muscles, and the rating of perceived exertion (RPE) in the low back during patient transfer. In total, 19 male physical therapists with chronic low back pain performed patient transfers with and without the application of postural taping on the low back. The kinematics of the lumbo–pelvic–hip complex and EMG activity of the erector spinae were recorded using a synchronized 3-D motion capture system and surface EMG. RPE was measured using Borg’s CR-10 scale. Differences in kinematic data, EMG activity, and RPE between the two conditions were analyzed using a paired t-test. Peak angle and range of motion (ROM) of lumbar flexion, EMG activity of the erector spinae, and RPE decreased significantly, while peak angle and ROM of pelvic anterior tilt and hip flexion increased significantly during patient transfer under the postural taping condition versus no taping (p<0.05). These findings suggest that postural taping can change back extensor muscle activity and RPE as well as the kinematics of the lumbo–pelvic–hip complex in physical therapists with chronic low back pain during patient transfer.

Comparison of the Lumbar Flexion Angle and EMG Activity in Trunk Muscles in Individuals with and without Limited Hip Flexion Range of Motion during Visual Display Terminal Work with Cross-Legged Sitting

[Purpose] The purpose of this study was to compare the lumbar flexion angle and electromyography (EMG) measurements of trunk muscle activity in individuals with and without limited hip flexion range of motion (ROM) during visual display terminal (VDT) work with cross-legged sitting. [Subjects] The 15 participants included a control group with sufficient hip flexion ROM (n = 7) and an experimental group with limited hip flexion ROM (n = 8). [Methods] All subjects performed VDT work with cross-legged sitting. The lumbar flexion angle was measured using a three-dimensional motion capture system, and the trunk muscle activity was recorded using a surface EMG system during VDT work with cross-legged sitting. The differences in trunk flexion angle and trunk muscle activity between the two groups were analyzed using independent t-tests. [Results] The lumbar flexion angle was significantly greater in the experimental group than the control group, although trunk muscle activity did not differ between the two groups. [Conclusion] These findings suggest that limited hip flexion leads to greater lumbar flexion during cross-legged sitting.

Effects of Proprioceptive Neuromuscular Facilitation Stretching and Static Stretching on Maximal Voluntary Contraction

This study was undertaken to investigate and compare the effects of proprioceptive neuromuscular facilitation (PNF) stretching and static stretching on maximal voluntary contraction (MVC). Thirteen male university students (age, 20 ± 1 years; height, 172.2 ± 4.6 cm; weight, 68.4 ± 6.7 kg; mean ± SD) completed 3 different conditions on 3 nonconsecutive days in randomized order: static stretching (SS), PNF stretching (PNF), and no stretching (control, CON). Each condition consisted of a 5-minute rest accompanied by one of the following activities: (a) control, (b) SS, or (c) PNF stretching. The hip flexion range of motion (ROM) was evaluated immediately before and after the activity. The MVC of knee flexion was then measured. Surface electromyography was recorded from the biceps femoris and vastus lateralis muscles during MVC tests and stretching. Although increases in ROM were significantly greater after PNF than after SS (p < 0.01), the decreases in MVC were similar between the 2 treatments. These results suggest that, although PNF stretching increases ROM more than SS, PNF stretching and SS is detrimental to isometric maximal strength.

Anterior Inferior Iliac Spine Deformity as an Extra-Articular Source for Hip Impingement: A Series of 10 Patients Treated With Arthroscopic Decompression

To describe an arthroscopic technique for decompression of a prominent anterior inferior iliac spine (AIIS) leading to extra-articular hip impingement and to provide short-term outcome after this procedure. We retrospectively reviewed office charts, imaging studies, operative reports, arthroscopic images, preoperative and postoperative hip flexion range of motion, and preoperative and postoperative modified Harris Hip Scores in a consecutive series of 10 male patients who had arthroscopic decompression of symptomatic AIIS deformities leading to extra-articular hip impingement. The procedure was performed through standard anterolateral and mid-anterior hip arthroscopy portals that were also used to explore the joint and address concomitant intra-articular pathologies. The mean age was 24.9 years, with 8 of 10 patients aged younger than 30 years. In 9 patients, an anterior cam lesion was identified and decompressed before the AIIS decompression. The mean follow-up time was 14.7 months (range, 6 to 26 months). Hip flexion range of motion improved from 99° ± 7° before surgery to 117° ± 8° after surgery (P < .001). The modified Harris Hip Score improved from 64 ± 18 before surgery to 98 ± 2 at latest follow-up after surgery (P < .001). Arthroscopic decompression of a symptomatic AIIS deformity is a reproducible procedure that can provide excellent outcomes at short-term follow-up. As opposed to using an open approach for decompressing a prominent AIIS, an arthroscopic approach may be of particular value in patients with mixed intra- and extra-articular sources of hip dysfunction, because it enables the surgeon to address all pathologies with a single arthroscopic procedure. Level IV, therapeutic case series.

The gait function of slipped capital femoral epiphysis in patients after growth arrest and its correlation with the clinical outcome

Slipped capital femoral epiphysis (SCFE) represents the preliminary stage of osteoarthritis. Reliable tools for outcome evaluation should be developed to prevent persisting defects. The functional outcome of SCFE-patients after growth arrest is analysed by instrumented 3D-gait analysis (GA). The results are matched to the clinical examination findings. A total of 39 SCFE patients after growth arrest (18.8 years; BMI 26.5 kg/m²) with unilateral affection were included. The clinical results were classified according to Harris hip and clinical Heyman Herndon scores. 3D-GA-parameters were evaluated and compared to the sound side and a group of 40 healthy adults (28.0 years; 21.9 kg/m²). The subgroup analysis was performed according to clinical results. The clinical examination revealed very good results. GA could detect even small alterations. Some parameters indicated sustained functional impairments: Compared to the control group patients' walking speed (p = 0.022), step frequency (p < 0.001) and single support of the slip side (p < 0.001) decreased, while step width (p = 0.014), double support (p = 0.004) and stance time of sound side increased (p = 0.001). For kinematics patients, the sagittal range of motion (ROM) of pelvis (p < 0.001) and the external rotation of the ankle on both sides increased (p = 0.011) and sagittal ROM of hip (p = 0.002) and knee flexion of slip side (p < 0.001) decreased. The sagittal ROM of the ankle on the slip side decreased compared to the sound side (p = 0.003). Subgroup analysis revealed a positive correlation between clinically unsatisfying results and GA parameters. Functional impairments in SCFE-patients can be found even after growth arrest. Alterations are explained partly by the disease and partly by patients' constitution. BMI-matched controls and long-term follow-up are needed.

Title: fit2dive - A field test for assessing the specific capability of underwater fin swimming with SCUBA

Exercise modalities such as cycle ergometry do not mimic the specific movements of fin swimming underwater. Therefore, there is a need to develop a specific diving capability assessment procedure. The purpose of the study was the application of a standardized field test to assess and rate underwater swimming performance. The fit2dive-test consists of an incremental protocol that is performed in a pool (<5 m depth). The underwater swimming speed is increased stepwise by 0.2 m·s-1, starting with 0.4 m·s-1 until the subject’s subjective exhaustion is attained. Time of break-off (fit2dive-time), swimming technique (e.g. range of motion (ROM) of hip and knee joints) and equipment configuration was recorded via a standardized checklist. Subjects with the highest hip and knee flexion had lower fit2dive-times (373 ± 119 s; p<0.01) than those in the normal hip and knee flexion ROM category (448 ± 104 s). Further, divers using full foot fins had significantly higher (p<0.001) fit2dive-times (474 ± 97 s) than divers with adjustable strap fins (375 ± 104 s). The fit2dive test indicates the specific capability of underwater fin swimming. The results allow identifying weak factors such as underwater swimming technique or equipment configuration.

In vivo kinematic analysis of squatting after total hip arthroplasty

BackgroundThe in vivo kinematics of squatting after total hip arthroplasty is unclear. The purpose of the present study was to determine the range of motion of the hip joint during squatting after total hip arthroplasty. MethodsUsing fluoroscopy, we investigated 15 primary cementless total hip arthroplasties performed using a computed tomography-based navigation system. An acetabular component with concavities around the rim and a femoral component with reduced neck geometry were used. The motion of the acetabular and femoral components based on the neutral standing position was analyzed using a two-dimensional to three-dimensional registration technique. FindingsNo prosthetic impingement occurred in any hips. The mean maximum hip flexion range of motion was 86.2° (range, 55.1°–117.4°) and was not always consistent with maximum squatting. The mean maximum pelvic posterior tilting angle was 25.7° (range, 5.5°–43.5°). The pelvis began to tilt posteriorly at 50°–70° of the hip flexion range of motion. At maximum squatting, the mean ratio of the pelvic posterior tilting angle to the femoral flexion angle was 23.2% (range, 3.8%–45.7%). The mean minimum angle up to the theoretical prosthetic impingement was 26.2° (range, 11.8°–39.8°). InterpretationAlthough this is a preliminary study, three-dimensional assessment of dynamic squatting motion after total hip arthroplasty using the two-dimensional to three-dimensional registration technique appears to enable elucidation of the range of motion of the hip joint, the contribution of pelvic posterior tilting, and the minimum angle up to theoretical prosthetic impingement during squatting.

Long-Handled Shoehorn Length, Body Mass Index, and Hip Range of Motion in Healthy Female Adults

We examined the effect that long-handled shoehorn (LHSH) length and body mass index (BMI) have on hip range of motion (ROM) in female adults. Thirty-eight female participants were asked to don a shoe using 18-, 24-, and 30-in. LHSHs. Significant differences in hip flexion were found between the 18- and the 24-in. shoehorns and between the 18- and the 30-in. shoehorns. A significant positive relationship was found between BMI and internal rotation for each of the LHSHs. The results suggest that healthy women with low BMLs using a 24- or 30-in. LHSH have the greatest chance of not violating hip flexion or hip internal rotation ROM precautions. Implications suggest that therapists consider individual BMI and available hip ROM before prescribing an LHSH. A follow-up study is needed involving populations who would likely benefit from using LHSHs.

Aerobic activity before and following short-duration static stretching improves range of motion and performance vs. a traditional warm-up

Many activities necessitate a high degree of static joint range of motion (ROM) for an extended duration. The objective of this study was to examine whether ROM could be improved with a short duration and volume of static stretching within a warm-up, without negatively impacting performance. Ten male recreationally active participants completed 2 separate protocols to examine changes in ROM and performance, respectively, with different warm-ups. The warm-up conditions for the ROM protocol were static stretching (SS), consisting of 6 repetitions of 6 s stretches; 10min of running prior to the SS (AS); and 5 min of running before and after the SS (ASA). The performance protocol included a control condition of 10min of running. Measures for the ROM protocol included hip flexion ROM, passive leg extensor tension, and hamstring electromyographic (EMG) activity at pre-warm-up, and at 1, 10, 20, and 30min post-warm-up. Performance measures included countermovement jump (CMJ) height, reaction time (RT), movement time (MT), and balance at pre-warm-up and at 1 and 10min post-warm-up. The ASA produced greater ROM overall than the SS and AS conditions (p< 0.0001), persisting for 30min. There were no significant alterations in passive muscle tension or EMG. For the performance protocol, there were no main effects for condition, but there was a main effect for time, with CMJ height being greater at 1 and 10min post-warm-up (p = 0.0004). Balance ratios and MT improved at 10min post-warm-up (p< 0.0001). Results indicate that the ASA method can provide ROM improvements for 30min with either facilitation or no impairment in performance. This may be especially important for athletes who substitute later into a game with minimal time for a full warm-up.

Validity and test-retest reliability of manual goniometers for measuring passive hip range of motion in femoroacetabular impingement patients.

BackgroundThe aims of this study were to evaluate the construct validity (known group), concurrent validity (criterion based) and test-retest (intra-rater) reliability of manual goniometers to measure passive hip range of motion (ROM) in femoroacetabular impingement patients and healthy controls.MethodsPassive hip flexion, abduction, adduction, internal and external rotation ROMs were simultaneously measured with a conventional goniometer and an electromagnetic tracking system (ETS) on two different testing sessions. A total of 15 patients and 15 sex- and age-matched healthy controls participated in the study.ResultsThe goniometer provided greater hip ROM values compared to the ETS (range 2.0-18.9 degrees; P < 0.001); good concurrent validity was only achieved for hip abduction and internal rotation, with intraclass correlation coefficients (ICC) of 0.94 and 0.88, respectively. Both devices detected lower hip abduction ROM in patients compared to controls (P < 0.01). Test-retest reliability was good with ICCs higher 0.90, except for hip adduction (0.82-0.84). Reliability estimates did not differ between the goniometer and the ETS.ConclusionsThe present study suggests that goniometer-based assessments considerably overestimate hip joint ROM by measuring intersegmental angles (e.g., thigh flexion on trunk for hip flexion) rather than true hip ROM. It is likely that uncontrolled pelvic rotation and tilt due to difficulties in placing the goniometer properly and in performing the anatomically correct ROM contribute to the overrating of the arc of these motions. Nevertheless, conventional manual goniometers can be used with confidence for longitudinal assessments in the clinic.

Mechanosensitivity during lower extremity neurodynamic testing is diminished in individuals with Type 2 Diabetes Mellitus and peripheral neuropathy: a cross sectional study

BackgroundType 2 Diabetes Mellitus (T2DM) and diabetic symmetrical polyneuropathy (DSP) impact multiple modalities of sensation including light touch, temperature, position sense and vibration perception. No study to date has examined the mechanosensitivity of peripheral nerves during limb movement in this population. The objective was to determine the unique effects T2DM and DSP have on nerve mechanosensitivity in the lower extremity.MethodsThis cross-sectional study included 43 people with T2DM. Straight leg raise neurodynamic tests were performed with ankle plantar flexion (PF/SLR) and dorsiflexion (DF/SLR). Hip flexion range of motion (ROM), lower extremity muscle activity and symptom profile, intensity and location were measured at rest, first onset of symptoms (P1) and maximally tolerated symptoms (P2).ResultsThe addition of ankle dorsiflexion during SLR testing reduced the hip flexion ROM by 4.3° ± 6.5° at P1 and by 5.4° ± 4.9° at P2. Individuals in the T2DM group with signs of severe DSP (n = 9) had no difference in hip flexion ROM between PF/SLR and DF/SLR at P1 (1.4° ± 4.2°; paired t-test p = 0.34) or P2 (0.9° ± 2.5°; paired t-test p = 0.31). Movement induced muscle activity was absent during SLR with the exception of the tibialis anterior during DF/SLR testing. Increases in symptom intensity during SLR testing were similar for both PF/SLR and DF/SLR. The addition of ankle dorsiflexion induced more frequent posterior leg symptoms when taken to P2.ConclusionsConsistent with previous recommendations in the literature, P1 is an appropriate test end point for SLR neurodynamic testing in people with T2DM. However, our findings suggest that people with T2DM and severe DSP have limited responses to SLR neurodynamic testing, and thus may be at risk for harm from nerve overstretch and the information gathered will be of limited clinical value.

Short-Duration Massage at the Hamstrings Musculotendinous Junction Induces Greater Range of Motion

Massage for the purpose of health dates back to early civilization and more recently has been used in the management and prevention of sport injuries. Massage has also been used as part of a warm-up to help increase acute flexibility. However, the physiological benefits and mechanisms of massage are not well known. The purpose of the present study was to investigate the effectiveness of 3 massage conditions on hip flexion range of motion (ROM). This experimentation involved a novel massage technique, which focused the massage on the musculotendinous junction for a short duration. Ten recreationally active women ranging from 21 to 36 years in age participated in this study. Participants were subjected to 3 massage conditions (no massage, 10-second massage, and 30-second massage) in a random order on separate days. Hip flexion angle, passive leg tension, and electromyography (EMG) were measured thrice before and within 10 seconds after the intervention. A main effect for conditions was found with the 30-second massage providing a 7.2% increase in hip flexion ROM that was significantly greater than the control condition (p < 0.05). Significant interactions occurred with an increased ROM (p < 0.05) from pre to posttests of 5.9 and 7.2% for the 10- and 30-second massage conditions, respectively. There were no significant differences in passive tension or EMG for any conditions or time. With a significant increase in hip angle and no associated increase in passive tension or EMG, there is a suggestion that 10 and 30 seconds of musculotendinous massage induces greater ROM through a modified stretch perception, increased stretch tolerance, or increased compliance of the hamstrings. Musculotendinous massage may be used as an alternative or a complement to static stretching for increasing ROM.

Chronic Flexibility Improvement After 12 Week of Stretching Program Utilizing the ACSM Recommendations: Hamstring Flexibility

The ACSM flexibility training recommendations emphasize proper stretching of muscles supporting the major joints, but there is a little evidence to support this recommendation in terms of effectiveness, and which stretching parameters (technique and single stretch duration) are more adequate. A randomized controlled clinical trial design was use to investigate whether the ACSM flexibility training recommendation parameters improve hip flexion range of motion. A total of 173 subjects, 122 men (21.3+/-2.5 years; 176.33+/-8.35 cm; 74.42+/-10.80 kg) and 51 women (20.7+/-1.6 years; 163.43+/-6.57 cm; 60.12+/-7.88 kg), classified as recreationally active young adult university students were randomly assigned to 1 of 7 groups: 1 control group (no stretching) or 1 of 6 stretching groups. All stretching groups performed 12 weeks of flexibility training with a consistent stretch daily dose (180 s) and frequency (3 days per week) parameters and different stretch technique (passive or active) and single stretch duration (15, 30, or 45 s). Hip flexion passive range of motion (PROM) was determined through the bilateral straight-leg raise test before, during (at 4 and 8 weeks), and after the program (12 weeks). All stretching groups performed hip flexion PROM after flexibility training. A significant improvement was identified in mean PROM for each stretching group, but no significant differences were found between stretch technique and single stretch duration (p>0.05). The control group's mean PROM decreased (Delta PROM: -0.08 degrees, 95% confidence interval [CI]=-2.3 to 5.3), whereas all stretching groups increased PROM (Delta PROM: 15.14 degrees, 95% CI=10.19 to 23.56) in hip flexion after 12 weeks of stretching (p<0.05). The present study suggests that the current ACSM flexibility training recommendations are effective for improving hip flexion ROM in recreationally active young adults.

Effect of 3 Different Active Stretch Durations on Hip Flexion Range of Motion

The purpose of this study was to evaluate the efficacy of 3 different durations of active stretch (12 x 15, 6 x 30, and 4 x 45 seconds) in a hamstring stretching exercise program on lower extremity range of motion (ROM) in young adults. A total of 150 subjects (age, 21.3 +/- 2.5 years; height, 173. 33 +/- 8.35 cm; weight, 70.42 +/- 10.80 kg) completed this study. Subjects were randomly assigned to 1 of 4 groups (3 treatment groups and 1 control group). The 3 treatment groups participated in an active stretching program 3 times per week for a 12-week period, holding each stretch exercise for a duration of 15, 30, or 45 seconds. The total daily dose of the stretches was 180 seconds for each group. The control group did not stretch. Passive hip flexion ROM was determined through the bilateral straight leg raise test before, during (at 4 and 8 weeks), and after the program using an inclinometer. Statistical analysis (p < 0.05) revealed a significant interaction of length of stretching program and improvement in ROM. Post hoc analysis showed that all 3 treatment groups increased hip flexion ROM from their initial values; however, the control group did not. No significant differences were found between the 3 treatment groups. This study indicates that 12 x 15-, 6 x 30-, and 4 x 45-second single durations of active stretching were equally effective at increasing hamstring length when performed 3 days per week for 12 weeks in this population.

Optimal Contraction Intensity During Proprioceptive Neuromuscular Facilitation for Maximal Increase of Range of Motion

An informal review of literature on the use of postisometric relaxation (PIR) type proprioceptive neuromuscular facilitation (PNF) indicates that the force of contraction requested from the athlete ranges from 10 to 100% of maximum voluntary isometric contraction (MVIC). The purpose of this study was therefore to determine if an optimal contraction intensity to elicit maximum positive change in range of motion (DeltaROM) exists. This research question was tested across a convenience sample of 56 (37 male and 19 female) university athletes. Target contractions during PNF interventions were set at 20, 50, and 100% MVIC. Pre- and post-PNF intervention hip flexion range of motion (ROM) was measured on a unilateral straight leg raise. The target MVIC of 20, 50, and 100% elicited mean pre-post intervention DeltaROM of 8.4, 12.9, and 11.6 degrees , respectively (all p < or = 0.0001). Differences in pre-post intervention DeltaROM between target contraction intensities were also significant (p = 0.016 to < or = 0.0001). A peak DeltaROM of 13.3 degrees was found at a PNF contraction intensity of 64.3% MVIC. Where optimizing increased ROM in healthy athletes is the desired outcome of PIR-PNF application, coaches and trainers should elicit contraction intensities of approximately 65% MVIC.

Effect of static and dynamic stretching on hamstring flexibility in the warm-up

Introduction: This study compared the acute effects of static and dynamic stretching in the warm-up, on hamstring flexibility using a reliable set-up for measurement.Methodology: Static and dynamic flexibility was measured using five modifications of the Straight Leg Raise test to measure hip flexion range of motion (deg). In the first part of the study (n = 33) hamstring flexibility was measured using a Static-passive, Static-active, Dynamic-supine and Dynamic-standing tests. The results of this study were used to calculate reliability statistics and to compare the various static and dynamic flexibility tests. This was followed by an intervention study (n = 12) where participants were randomly assigned to three intervention treatments of 225 s on separate days: No stretching (Treatment 1), static stretching (Treatment 2) and dynamic stretching (Treatment 3) in a cross-over study design. Results/conclusion: There was a significant difference between Static-passive and the Dynamic-supine hamstring flexibility tests (p .05). When dynamic stretches were included in the warm-up instead of static stretches, it was expected that there would be changes, at least, in dynamic flexibility of the hamstrings. The analysis shows that there were statistically significant differences in both static (t (11) = 2.62, p < .05) and dynamic (t (11) = 5.69, p < .05). These findings were confirmed by non-parametric tests.Static stretching only influenced static flexibility (Wilcoxon, Z =-2.67, p < .05) of the hamstrings, while dynamic stretching produced changes in both static (Wilcoxon, Z =-2.39, p < .05) and dynamic flexibility (Wilcoxon, Z =-2.98, p < .05). The results have implications for the specificity of stretching in sport.

AN IMPAIRMENT-BASED INTERVENTION FOR A PATIENT WITH NON-SPECIFIC BILATERAL HIP PAIN: CLINICAL AND BIOMECHANICAL OUTCOMES

Study design: Case study. Background: To date, there is little research that has examined the association of impairments at the hip with cumulative trauma syndromes of the hip. The purposes of this case report are to: (1) describe clinical outcomes for a patient with non-specific bilateral musculoskeletal hip pain associated with recreational walking, (2) explore the relationship between this patient's impairments and her cumulative trauma syndrome at the hip, and (3) integrate biomechanical analysis with this patient's clinical diagnosis. Case description: The patient was a 28-year-old female research assistant who reported anterior bilateral hip pain during recreational walking. After examination, the physical therapist diagnosed primary impairments of hip pain, limited hip flexion range of motion (ROM), and weakness of hip musculature, resulting in her ambulation limitations. Intervention consisted of a home exercise program (HEP) designed to strengthen the iliopsoas, gluteus maximus, and gluteus medius (specifically, the posterior portion), increase extensibility of the IT Band and medial hamstrings, and promote posterior glide of the proximal femur. The patient's HEP was the only intervention she received. There were follow-up telephone conversations, but no clinical re-examination for ten weeks. The patient performed the HEP a total of 41 days over the ten week period. Biomechanical gait analysis was performed pre- and post-intervention. Outcomes: Following intervention, the patient was pain-free during recreational walking, and passive hip flexion ROM and manual muscle testing (MMT) grades of hip musculature improved. Global score on the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) improved ten points. Motion analysis, force plate analysis, and electromyography (EMG) showed that maximum hip extension decreased, maximum hip flexion increased, maximum ground reaction force increased, activation of the gluteus maximus increased, while activation of the gluteus medius and tensor fascia latae (TFL) decreased following the intervention. Discussion: This patient's changes in muscle activity following a HEP appear largely consistent with improved symptoms based on theoretical descriptions of a common muscle imbalance (shortened and overactive TFL and weakness of the gluteus maximus and posterior portion of the gluteus medius), thought to contribute to increased femoral medial rotation.

Hip flexion range of motion and physical function in hip osteoarthritis: Mediating effects of hip extensor strength and pain

Hip flexion range of motion (ROM), hip extensor strength (torque production), and hip pain are important correlates of physical function in individuals with hip osteoarthritis (OA). However, the relationships among these variables remain unclear. The purpose of this study was to examine whether hip extensor strength and hip pain mediate the association between hip flexion ROM and physical function. Participants were 100 adults (mean age 62 years) with radiographically confirmed hip OA. Passive hip flexion ROM was measured using a digital inclinometer, and isometric hip extensor strength was measured using a force transducer. Self-report measures of physical function and pain were assessed by the Short Form 36 (SF-36) questionnaire, and physical performance was assessed by the gait speed, step test, and stair climb test. Multiple mediation analyses, adjusted for demographic and anthropometric measures, revealed that the association between hip flexion ROM and SF-36 physical function scores was fully mediated by SF-36 bodily pain scores and hip extensor strength. Hip extensor strength mediated the hip flexion effects on gait speed and step test performance, while the SF-36 bodily pain scores mediated the hip flexion stair performance association. In individuals with symptomatic hip OA, hip pain and hip extensor strength mediated the influence of hip flexion ROM on physical function. These results suggest that interventions to improve the range of hip motion may be clinically indicated.

Intrarater Test-Retest Reliability of Hip Range of Motion and Hip Muscle Strength Measurements in Persons With Hip Osteoarthritis

Pua YH, Wrigley TW, Cowan SM, Bennell KL. Intrarater test-retest reliability of hip range of motion and hip muscle strength measurements in persons with hip osteoarthritis. Objective To examine the relative and absolute intrarater test-retest reliability of muscle strength and range of motion (ROM) measurements of the hip performed in people with hip osteoarthritis. Design Repeated measures. Setting Human movement laboratory of a university. Participants Participants (N=22; 10 men, 12 women; age range, 50-84y) with hip osteoarthritis. Interventions On 2 separate occasions, at least 1 week apart, isometric torque measurements were obtained from the hip rotators, flexors, abductors, and extensors. Passive ROMs in hip rotation, flexion, abduction, and extension were also determined. Main Outcome Measures Relative reliability was estimated using the intraclass correlation coefficient, model 2,2 (ICC 2,2). Absolute reliability was estimated using the coefficient of variation (CV) and the standard error (SE) of measurement. Results For measurements of muscle strength, ICC 2,2 ranged from .84 to .97, and the CV ranged from 8% to 15.7%. Hip extensors and internal and external rotators showed high ICC 2,2 (>.96) and low CV (<9.8%); hip abductors showed the lowest ICC 2,2 (.84) and the highest CV (15.7%). For ROM measurements, ICC 2,2 ranged from .86 to .97 and SE ranged from 3.1° to 4.7°. Hip flexion ROM showed the highest ICC 2,2 (.97) and an SE of 3.5°; hip extension ROM showed the lowest ICC 2,2 (.86) and the highest SE (4.7°). Conclusions Strength and ROM testing of the hip in people with hip osteoarthritis can be performed with good to excellent reliability.