Acute effects of static active or dynamic active stretching on eccentric-exercise-induced hamstring muscle damage.

OBJECTIVES: To examine whether an acute bout of active or dynamic hamstring-stretching exercises would reduce the amount of muscle damage observed after a strenuous eccentric task and to determine whether the stretching protocols elicit similar responses. DESIGN: A randomized controlled clinical trial. METHODS: Thirty-six young male students performed 5 min of jogging as a warm-up and were allocated to 1 of 3 groups: 3 min of static active stretching (SAS), 3 min of dynamic active stretching (DAS), or control (CON). All subjects performed eccentric exercise immediately after stretching. Heart rate, core temperature, maximal voluntary isometric contraction, passive hip flexion, passive hamstring stiffness (PHS), plasma creatine kinase activity, and myoglobin were recorded at prestretching, at poststretching, and every day after the eccentric exercises for 5 d. RESULTS: After stretching, the change in hip flexion was significantly higher in the SAS (5°) and DAS (10.8°) groups than in the CON (-4.1°) group. The change in PHS was significantly higher in the DAS (5.6%) group than in the CON (-5.7%) and SAS (-6.7%) groups. Furthermore, changes in muscle-damage markers were smaller in the SAS group than in the DAS and CON groups. CONCLUSIONS: Prior active stretching could be useful for attenuating the symptoms of muscle damage after eccentric exercise. SAS is recommended over DAS as a stretching protocol in terms of strength, hamstring range of motion, and damage markers.

Two stretching treatments for the hamstrings: proprioceptive neuromuscular facilitation versus kinesio taping.

CONTEXT: Recent studies have shown that the static stretch (SS) may adversely affect leg-muscle performance. OBJECTIVES: The authors examined the short-term effects of 2 stretching exercises on hamstrings muscle before and after exercise. DESIGN: Crossover. SETTING: Laboratory. PARTICIPANTS: 9 healthy, physically active men. INTERVENTIONS: There were 3 protocols in a randomized order with a 7-d interval: nonstretching (CON protocol), hamstrings static stretching (SS) with proprioceptive neuromuscular facilitation (PNF), and SS with kinesio-taping application on the hamstrings. MAIN OUTCOME MEASURES: Outcome measures included first-felt and maximum tolerant-felt range of motion (FROM and TROM), maximal knee-flexion peak torque (PT) at 180°/s, and hamstrings muscle stiffness. RESULTS: Groups were not different at prestretching in terms of hamstrings flexibility, PT, and muscle stiffness. At poststretching, both stretching protocols showed significant increases in FROM and TROM (P < .05). Stiffer hamstrings muscle and decreased PT were found in both SS+PNF and CON protocols (P < .05). However, there was no significant difference in the SS+Taping protocol (P > .05). CONCLUSION: The stretching protocols improve hamstrings flexibility immediately, but after exercise hamstrings peak torque is diminished in the SS+PNF but not in the SS+Taping group. This means that SS+Taping can prevent negative results from exercise, which may prevent muscle injury.

Electromechanical delay of the vastus medialis obliquus and vastus lateralis in individuals with patellofemoral pain syndrome.

STUDY DESIGN: Case-control study. OBJECTIVE: To examine electromechanical delay (EMD) of the vastus medialis obliquus (VMO) and the vastus lateralis (VL) in individuals with patellofemoral pain syndrome (PFPS). BACKGROUND: EMD is a mechanical property of muscles related to protective reflex and sports performance. The time duration of the EMD can be shortened with strength training and, conversely, can be lengthened secondary to immobilization. However, it is unclear if EMD between various components of the quadriceps is affected in individuals with PFPS. METHODS: Twenty-six individuals with PFPS and 26 healthy volunteers were studied. The VMO and VL were electrically stimulated to evoke muscle twitches. Ultrasound was used to assess patellar movement elicited by the muscle twitch. The time from the onset of electrical stimulation to the onset of patellar movement was measured as the EMD. The EMDs of the VMO and VL were compared between groups using a mixed-model analysis of variance. RESULTS: Subsequent to a significant interaction (P<.001), post hoc analysis indicated that the EMD of the VMO was longer (PFPS, 37.3 ± 0.7 milliseconds; control, 25.9 ± 0.7 milliseconds; P<.001) and the EMD of the VL was shorter (PFPS, 18.4 ± 0.5 milliseconds; control, 25.1 ± 0.5 milliseconds; P<.001) in the PFPS group. Therefore, in the individuals with PFPS, the EMD of the VMO was significantly longer than that of the VL (P<.001), which was not the case for those in the control group (P = .20). CONCLUSION: The mechanical properties of the VMO and VL may be altered in patients with PFPS.J Orthop Sports Phys Ther 2012;42(9):791-796, Epub 2 August 2012. doi:10.2519/jospt.2012.3973.

Effectiveness of the end-range mobilization and scapular mobilization approach in a subgroup of subjects with frozen shoulder syndrome: a randomized control trial.

Treatment strategies targeting abnormal shoulder kinematics may prevent pathology or if the pathology develops, shorten its duration. We examined the effectiveness of the end-range mobilization/scapular mobilization treatment approach (EMSMTA) in a subgroup of subjects with frozen shoulder syndrome (FSS). Based on the kinematics criteria from a prediction method, 34 subjects with FSS were recruited. Eleven subjects were assigned to the control group, and 23 subjects who met the criteria were randomly assigned to the criteria-control group with a standardized physical therapy program or to the EMSMTA group. Subjects attended treatment sessions twice a week for 8 weeks. Range of motion (ROM), disability score, and shoulder complex kinematics were obtained at the beginning, 4 weeks, and 8 weeks. Subjects in the EMSMTA group experienced greater improvement in outcomes compared with the criteria-control group at 4 weeks (mean difference=0.2 of normalized hand-behind-back reach) and 8 weeks (mean difference=22.4 degrees humeral external rotation, 0.31 of normalized hand-behind-back reach, 7.5 disability, 5 degrees tipping and 0.32 rhythm ratio). Similar improvements were found between the EMSMTA group and control group. The EMSMTA was more effective than a standardized physical therapy program in a subgroup of subjects who fit the criteria from a prediction method.

The role of patellar alignment and tracking in vivo: the potential mechanism of patellofemoral pain syndrome.

PURPOSE AND METHOD: Lateral patellar malalignment and maltracking are commonly believed to be associated with patellofemoral pain. In the current review, a computerized and manual search of English-language articles was performed using multiple combinations of the following keywords: 'patellofemoral pain syndrome' or 'patellofemoral pain', and 'patellar alignment' or 'patellar tracking'. The role of patellar alignment and tracking in vivo is discussed via a review of papers regarding the differences in asymptomatic and symptomatic patella. An attempt is made to identify the potential mechanism of patellofemoral pain syndrome (PFPS). CONCLUSION: Evidence suggests that symptomatic patella do not consistently demonstrate lateral malalignment or tracking in patellar tilt and translation. Abnormal patellar alignment and tracking may be potential risk factors that are associated with patellofemoral pain. Other contributing factors should be considered in dealing with patellofemoral pain syndrome. Further studies are required to determine what normal patella alignment and tracking is before going on to define how these are altered in subjects with patellofemoral pain. Furthermore, prospective studies are needed to identify the alteration of patellofemoral kinematics, if any, and whether these are the causative factor or the consequence of the patellofemoral pain syndrome, as well as to determine the risk of development of patellofemoral pain syndrome in individuals with and without abnormal patellar tracking.

Reliability and relationship between 2 measurements of transversus abdominis dimension taken during an abdominal drawing-in maneuver using a novel approach of ultrasound imaging.

STUDY DESIGN: Reliability study of clinical measurement. OBJECTIVES: The primary purpose was to develop a reliable method for measuring muscle length changes of the transversus abdominis (TrA) during contraction. The secondary purpose was to investigate the relationship between changes in thickness and length (as indicated by the lateral sliding of the anterior muscle-fascia junction) of the TrA muscle during an abdominal drawing-in maneuver. We also provide data on between-day reliability of change in thickness (ΔT) of the TrA. BACKGROUND: Ultrasound imaging measurements of TrA thickness at rest (Thr) and during maximal contraction (Thm) have been shown to be reliable. However, limited data exist on quantifying changes in TrA length (as indicated by the lateral sliding of the muscle-fascia junction [Δx]) and ΔT during contraction. METHODS: Eighteen healthy adults (mean ± SD age, 22.6 ± 2.5 years) participated in this study. Brightness mode ultrasound images of the TrA were collected at rest and during an abdominal drawing-in maneuver. Subjects were examined by the same examiner twice within a 48-hour period. ΔT, ΔT/Thr, Thr, Thm, and Δx of the TrA were calculated. Medial-lateral movement of the transducer during measurement was corrected through a custom-written program that used an internal marker created by an echo-absorptive thread attached to the skin. Intraclass correlation coefficients (ICC3,1), within-subject coefficient of variance, and standard error of measurement were calculated. The relationship between ΔT and adjusted Δx of the TrA muscle was investigated. RESULTS: The ICC values for Thr, Thm, and ΔT of the TrA muscle were greater than 0.75, with the exception of the left ΔT (0.62) and left ΔT/Thr (0.49). After adjusting for medial-lateral motion of the transducer, the ICC values of adjusted Δx were above 0.75, and the within-subject coefficient of variance was below 10%. There was no significant correlation between ΔT and adjusted Δx of the TrA. CONCLUSION: Ultrasound imaging measurements of TrA thickness and length change were shown to be reliable using a novel method to control for medial-lateral transducer motion. Measuring different but unrelated dimensional changes in the TrA might provide further insight as to the function of the TrA.

Scapular kinematics and impairment features for classifying patients with subacromial impingement syndrome.

Subacromial impingement syndrome (SAIS), which is associated with pain and a loss of function, has a high occurrence in the physically active population. Not all patients respond positively to treatment. Classifying patients can improve decision-making. The scapular kinematic and clinical impairments can aid in classifying the patients who are more likely to respond to physical therapy treatment. Thirty-three subjects (males, 20-33 years) presenting SAIS were studied to determine altered scapular kinematics and clinical impairments. Three measurements were collected: (1) three-dimensional scapular kinematics during performing functional tasks; (2) impairment outcomes of range of motion and muscle force; and (3) self-reported measurements of pain, satisfaction, and function. All patients received 6-week (2 times per week) physical therapy treatment. Improvement with treatment was determined using the Global Rating of Change Scale. Scapular kinematics and clinical impairments were first identified by t-test in predicting improvement and then combined into a multivariate prediction method. A prediction method with three variables (Flexilevel Scale of Shoulder Function score < 41, muscle power of serratus anterior < 27.4% body weight, degree of scapular internal rotation at 30° shoulder elevation during descending arm phase in unloaded condition<0.7°) were identified. It appears that scapular kinematics and impairment features can be used to classify subjects with SAIS in addition to self-report. Prospective validation of the proposed prediction method requires further investigation.

Reduced scapular muscle control and impaired shoulder joint position sense in subjects with chronic shoulder stiffness.

The purpose of the present study was to determine (1) if joint position sense (JPS) in subjects with shoulder stiffness (SS) differs from that in controls; (2) if, when JPS is reduced in SS, it is related to scapular muscular activities in the mid/end ranges of motion; and (3) if a person's function is associated with his or her level of JPS. Eighteen subjects with unilateral SS and 18 controls were included. Each subject performed abduction by self-selecting an end/mid range position. The electromagnetic motion-capturing system collected kinematic data while surface electromyography collected muscle activities (upper trapezius, lower trapezius, and serratus anterior muscles). Subjects were asked to move the upper limb to the target position (end/mid range) accurately without visual guidance. Reduced JPS was observed in subjects with SS (2.7 degrees in mid range, p<0.05). The JPS was enhanced by an increased scapula muscular activation level in the end range of motion (R=-0.61 for SS and -0.41 for controls) and by coordination among muscles' activation in the mid-range of motion (R=-0.87 for SS and R=-0.53 for controls). Impaired JPS was also related to self-reported functional status (R=-0.56) in subjects with SS. Shoulder JPS in subjects with chronic SS is impaired in comparison with controls. In the mid-range motion, the coordination of scapula muscular activation is related to shoulder JPS. Impaired JPS is also function-related in subjects with SS. These findings suggest that the coordination among scapula muscles' activation were important to consider in the rehabilitation of patients with chronic SS.

Effects of weight-bearing versus nonweight-bearing exercise on function, walking speed, and position sense in participants with knee osteoarthritis: a randomized controlled trial.

OBJECTIVE: To investigate whether weight-bearing (WB) exercise enhances functional capacity to a greater extent than nonweight-bearing (NWB) exercise in participants with knee osteoarthritis. DESIGN: Randomized controlled trial. SETTING: Kinesiology laboratory. PARTICIPANTS: Participants (N=106) were randomly assigned to WB exercise, NWB exercise, or a control group (no exercise). INTERVENTION: WB exercise and NWB exercise groups underwent an 8-week knee extension-flexion exercise program. MAIN OUTCOME MEASURES: Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) function scale, walking speed, muscle torque, and knee reposition error were assessed before and after intervention. RESULTS: Equally significant improvements were apparent for all outcomes after WB exercise and NWB exercise, except for reposition error, for which improvement was greater in the WB exercise group. In contrast, there were no improvements in the control group. CONCLUSIONS: Simple knee flexion and extension exercises (WB and NWB) performed over 8 weeks resulted in significant improvement in the WOMAC function scale and knee strength compared with the control group. NWB exercise alone may be sufficient enough to improve function and muscle strength. The additional benefit of WB exercise was improved position sense, which may enhance complex walking tasks (walking on figure of 8 route and spongy surface).

Differences in sonographic characteristics of the vastus medialis obliquus between patients with patellofemoral pain syndrome and healthy adults.

BACKGROUND: There is controversy regarding the relationship between patellofemoral pain syndrome (PFPS) and insufficiency of the vastus medialis obliquus (VMO). The conventional clinical practice of VMO strengthening for PFPS has been challenged for lack of evidence. The purpose of this study was to observe the difference in sonographic findings of the VMO between patients with PFPS and healthy adults. HYPOTHESIS: The morphological characteristics of the VMO are different between patients with PFPS and healthy adults. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: Fifty-four patients with PFPS and 54 age-, gender-, body height-, and body weight-matched healthy adults as controls were enrolled in the study to measure by sonography the insertion level, fiber angle, and volume of the VMO at its insertional portion to detect differences between patients with PFPS and healthy controls. RESULTS: The insertion level, fiber angle, and VMO volume were all significantly smaller in the PFPS group than in the control group (P < .05). Multivariate analysis of variance has revealed a Wilks lambda value of .845 and an F value of 5.640 (P = .001). CONCLUSION: There was a significant difference in the 3 VMO measures between patients with PFPS and the healthy controls. Individuals might be predisposed to PFPS by different VMO characteristics, including insertion level and fiber angle. The current study cannot determine whether the observed morphological differences were the results of atrophy in response to pain or if they represent dysplasia that was predisposed to pain development. The clinical manifestations of VMO characteristics should be thoroughly investigated in other populations. CLINICAL RELEVANCE: The function of the VMO is important to consider in the rehabilitation of patients with PFPS.

Efficacy of 2 non-weight-bearing interventions, proprioception training versus strength training, for patients with knee osteoarthritis: a randomized clinical trial.

STUDY DESIGN: Randomized clinical trial. OBJECTIVE: To investigate the clinical and functional efficacy of 2 different non-weight-bearing exercise regimens, proprioceptive training (PrT) versus strength training (ST), for patients with knee osteoarthritis (OA). BACKGROUND: Both strength and proprioceptive training are important interventions for individuals with knee OA. The benefits of weight-bearing exercises are generally recognized in the clinical setting. However, exercising in a standing or weight-bearing position may aggravate symptoms in patients with knee OA. METHODS AND MEASURES: One hundred eight patients were randomly assigned to the PrT, ST, or no exercise (control) group for an 8-week intervention. Both the PrT and ST interventions consisted of non-weight-bearing exercises. Western Ontario and McMaster Universities Osteoarthritis Index-pain (WOMAC-pain) and -function scores, walking time on 3 different terrains, knee strength, and absolute knee reposition error were assessed before and after intervention. Data were analyzed using mixed-model ANOVAs. RESULTS: Both PrT and ST significantly improved WOMAC-pain and -function score after intervention (P<.008). The improvement secondary to ST in the WOMAC-function scores (17.2 points) and for knee extension strength (10.3-14.9 Nm) was greater than the minimally clinically important difference for these measurements. The PrT group demonstrated greater improvement in walking time on a spongy surface and knee reposition error than the other 2 groups. No improvements were apparent in the control group. CONCLUSION: Both types of non-weight-bearing exercises (PrT and ST) significantly improved outcomes in this study. PrT led to greater improvements in proprioceptive function, while ST resulted in a greater increase in knee extensor muscle strength.

The effects of quadriceps contraction on different patellofemoral alignment subtypes: an axial computed tomography study.

STUDY DESIGN: Controlled laboratory study. BACKGROUND: The effect of quadriceps contraction on patellar alignment in patients with patellofemoral pain syndrome (PFPS) is debated and may vary based on patellar alignment subtypes measured with the quadriceps relaxed. OBJECTIVES: To determine if the effects of quadriceps contraction on patellar alignment differs (1) with respect to patellar alignment subtype in individuals with PFPS and (2) between symptomatic and asymptomatic knees in individuals with unilateral PFPS. METHODS AND MEASURES: Seventy-eight individuals, 47 with bilateral and 31 with unilateral PFPS, participated in the study. On axial computed tomography images with the knee in extension with quadriceps relaxed as well as contracted, patellar lateral condyle index (PLCI) and patellar tilt angle (PTA) were measured and analyzed. Based on the median PLCI and PTA alignment values measured with quadriceps relaxed for the 78 subjects, 4 subgroups of subjects were created: type 1, laterally displaced; type 2, laterally displaced and tilted; type 3, laterally tilted; and type 4, neither. RESULTS: Quadriceps contraction caused an increase in PLCI in all patellar alignment types (P<.01), with no difference in the magnitude of the increase between types (P>.05). PTA decreased with quadriceps contraction in the subjects with the type 3 initial patellar alignment (P<.01), with a significant difference in the change in patellar alignment between the subjects with type 3 and type 1 initial patellar alignment (P=.004). For the 31 subjects with unilateral PFPS, quadriceps contraction caused a similar change in PLCI and PTA in both the symptomatic and asymptomatic knees. CONCLUSIONS: The initial position of the patella with the quadriceps relaxed did not influence the change in PLCI with quadriceps contraction. For the 31 subjects with PFPS, there was no difference in initial alignment as well as in change of alignment with quadriceps contraction between symptomatic and asymptomatic knees.

Surplus value of hip adduction in leg-press exercise in patients with patellofemoral pain syndrome: a randomized controlled trial.

BACKGROUND: A common treatment for patients with patellofemoral pain syndrome (PFPS) is strength (force-generating capacity) training of the vastus medialis oblique muscle (VMO). Hip adduction in conjunction with knee extension is commonly used in clinical practice; however, evidence supporting the efficacy of this exercise is lacking. OBJECTIVE: The objective of this study was to determine the surplus effect of hip adduction on the VMO. DESIGN: This study was a randomized controlled trial. SETTING: The study was conducted in a kinesiology laboratory. PARTICIPANTS: Eighty-nine patients with PFPS participated. INTERVENTION: Participants were randomly assigned to 1 of 3 groups: hip adduction combined with leg-press exercise (LPHA group), leg-press exercise only (LP group), or no exercise (control group). Training consisted of 3 weekly sessions for 8 weeks. MEASUREMENTS: Ratings of worst pain as measured with a 100-mm visual analog scale (VAS-W), Lysholm scale scores, and measurements of VMO morphology (including cross-sectional area [CSA] and volume) were obtained before and after the intervention. RESULTS: Significant improvements in VAS-W ratings, Lysholm scale scores, and VMO CSA and volume were observed after the intervention in both exercise groups, but not in the control group. Significantly greater improvements for VAS-W ratings, Lysholm scale scores, and VMO volume were apparent in the LP group compared with the control group. There were no differences between the LP and LPHA groups for any measures. LIMITATIONS: Only the VMO was examined by ultrasonography. The resistance level for hip adduction and the length of intervention period may have been inadequate to induce a training effect. CONCLUSIONS: Similar changes in pain reduction, functional improvement, and VMO hypertrophy were observed in both exercise groups. Incorporating hip adduction with leg-press exercise had no impact on outcome in patients with PFPS.

A novel method for measuring electromechanical delay of the vastus medialis obliquus and vastus lateralis.

Electromechanical delay (EMD) of the vastus medialis obliquus (VMO) and vastus lateralis (VL) is determined by measuring the interval between the time of onset of muscle activities and the time of onset of mechanical output. However, individual mechanical output of the VMO or the VL cannot be obtained with the conventional method because of the knee extension force as the mechanical output. Therefore, the objective of the present study was to develop a new method for measuring EMD of the VMO and VL individually. Twelve healthy volunteers participated in the experiment. The motor point of the target muscle was electrically stimulated to evoke a muscle twitch. Simultaneously, the electrical stimulation signal was transmitted to ultrasound apparatus via the electrocardiography input channel. The ultrasound apparatus was used to capture the patellar movement elicited by the muscle twitch. EMD was measured from the onset of the electrical stimulation to the onset of patellar movement. The results showed that the intraclass correlation coefficients for the reproducibility of the EMD measurements of the VMO and VL were greater than 0.8. The EMDs of the VMO and VL were 18.3 +/- 2.2 ms and 24.8 +/- 5.8 ms, respectively. This new method provides a more precise measurement of EMD in the VMO and VL than does the conventional method because of the use of patellar movement as the mechanical output.

Proprioception assessment in subjects with idiopathic loss of shoulder range of motion: joint position sense and a novel proprioceptive feedback index.

We examined the effects of elevation range and plane on shoulder joint proprioception in subjects with idiopathic loss of shoulder range of motion (ROM). Joint position sense (JPS) and a novel proprioceptive feedback index (PFI), including difference magnitude and the similarity index, were used to assess proprioception. Twelve subjects (eight male, four female) with involved stiff shoulders and normal opposite shoulders were recruited from a university hospital. Subjects attempted to repeat six target positions. Target positions consisted of arm elevation in three planes (frontal, scapular, and sagittal planes) and two ranges (end/mid range). Six trials of each target position were used to determine acceptable trials for stabilization of the data, less than 5% of the cumulative mean values for at least three successive trials. The data stabilized at the sixth repetition. Compared to control shoulders, involved shoulders had enhanced proprioception during end range movements (p < 0.05). The magnitude of the repositioning error and difference magnitude decreased (1.6 degrees -3.5 degrees for repositioning error and 22.2 degrees -62.1 degrees for difference magnitude), whereas similarity index improved at end range movements compared to mid range movements (p < 0.05) in involved stiff shoulders. Results of JPS and PFI suggest that both capsuloligamentous and musculotendinous mechanoreceptors play an important role in proprioception feedback during active movements in subjects with idiopathic loss of shoulder ROM.

Association between sonographic morphology of vastus medialis obliquus and patellar alignment in patients with patellofemoral pain syndrome.

STUDY DESIGN: Descriptive, correlational, anatomical laboratory study. OBJECTIVES: To investigate the association between the morphology of the vastus medialis obliquus (VMO) and patellar alignment in patients with patellofemoral pain syndrome (PFPS). BACKGROUND: It has long been presumed that PFPS results from patellar malalignment. Strengthening of the VMO has been suggested as an intervention to treat individuals with PFPS, through correction of abnormal patellar tracking. However, the exact role of the VMO in the etiology and treatment of PFPS is not clear. METHODS AND MEASURES: This study included 58 patients with PFPS, of which 31 had bilateral involvement. A total of 89 knees were imaged with a Merchant's view radiograph at 45 degrees of knee flexion to measure patellar alignment consisting of patellar tilt and congruence angles. Those 89 knees were also examined with sonography with the knee in full extension and quadriceps relaxed to measure VMO morphology and additional characteristics such as insertion level, insertion ratio, fiber angle, and volume. The level of association between radiographic and sonographic measurements was explored to determine any relationship between patellar alignment and morphology of the VMO. RESULTS: The patellar tilt angle was negatively correlated with the VMO insertion level (r = -.58, P<.05), insertion ratio (r= -.52, P<.05), and volume (r = -.45, P<.05). In addition, the patellar congruence angle was negatively correlated with the VMO fibers angle (r = -.23, P<.05). CONCLUSIONS: This study showed that some aspects of VMO morphology, measured in full knee extension with the quadriceps relaxed, were associated with patellar alignment measured with the knee at 45 degrees of flexion. Whether or not VMO morphology serves as a predictor of patella alignment with the knee extended should be the focus of future investigations.

Efficacy of a target-matching foot-stepping exercise on proprioception and function in patients with knee osteoarthritis.

STUDY DESIGN: A randomized clinical trial design. OBJECTIVE: To investigate the efficacy of high, repetitive, target-matching foot-stepping exercise (TMFSE) performed in a sitting position on proprioception, functional score, and walking velocity for patients with knee osteoarthritis (OA). BACKGROUND: Researchers have suggested that exercises to address knee OA should include proprioceptive training. However, most patients cannot tolerate conventional proprioceptive training performed in a standing position. METHODS AND MEASURES: Forty-nine subjects (mean age +/- SD, 63.3 +/- 8.1) with knee OA were randomly assigned to the exercise or no intervention groups. The exercise group practiced TMFSE in sitting, 3 sessions weekly for 6 weeks. All subjects underwent assessments of knee reposition error, functional incapacity score, and walking velocity prior to and after intervention. RESULTS: The TMFSE significantly improved reposition error from a mean +/- SD of 3.0 degrees +/- 1.6 degrees to 1.5 degrees +/- 0.6 degree, walking velocity on ground level from 44.1 +/- 2.9 to 38.6 +/- 2.5 sec for 60 meters, time to complete a stairs task from 34.2 +/- 2.1 to 26.5 +/- 2.3 seconds, time to complete a figure-of-eight from 51.3 +/- 6.7 to 29.1 +/- 3.6 seconds, and score on a functional incapacity scale from 12.0 +/- 3.1 to 4.9 +/- 1.7, in subjects with knee OA after 6-week intervention (P <.0125). In contrast, the control group showed no change in any of the measured tests. CONCLUSION: TMFSE in sitting appears to be an option for exercise in patients with mild to moderate knee OA. This may be an especially attractive option for patients who may have pain with weight-bearing exercises. A longitudinal study with a larger sample size is needed to confirm the potential use of TMFSE for patients with knee OA.

Role of the vastus medialis obliquus in repositioning the patella: a dynamic computed tomography study.

BACKGROUND: It has been assumed that patellofemoral pain syndrome results from patellar malalignment. The precise role the vastus medialis obliquus plays in mediating the underlying pathologic abnormality is unclear. HYPOTHESIS: The morphologic characteristics of the vastus medialis obliquus correlate to patellar malalignment in patients with patellofemoral pain syndrome. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: One hundred twelve patients with patellofemoral pain syndrome were studied. Six sets of computed tomography axial images were assessed in which knee flexion was 0 degrees, 15 degrees, or 30 degrees and the quadriceps muscle either relaxed or contracted. Measurements of serial cross-sectional areas of the vastus medialis obliquus and patellar malalignment were made. Correlation and stepwise regression models between the vastus medialis obliquus variables and patellar malalignment (lateral shift and patellar tilt) were calculated. Statistics were calculated on 4 subgroups depending on patellofemoral malalignment type. RESULTS: Significant correlations were found between measures of cross-sectional areas of vastus medialis obliquus and patellar tilt at 0 degrees and 30 degrees of knee flexion. Using a regression model, it was determined that vastus medialis obliquus is predictive of patellar tilt (R(2) = 0.078-0.130). This explanation was most apparent in the subgroup of patients with extreme patellar tilt and lateral shift malalignments (R(2) up to 0.824). CONCLUSION: There are significant correlations between vastus medialis obliquus variables and patellar malalignments in extended knees of patients with patellofemoral pain syndrome. CLINICAL RELEVANCE: Vastus medialis obliquus muscle function is important to consider in the rehabilitation of patients with patellofemoral pain syndrome, especially those with extreme patellar tilt and lateral shift malalignments.

Different effects of femoral and tibial rotation on the different measurements of patella tilting: An axial computed tomography study.

BACKGROUND: The various measurements of patellar tilting failed to isolate patellar tilting from the confounding effect of its neighboring bone rotation (femoral and tibial rotation) in people sustaining patellofemoral pain (PFPS). Abnormal motions of the tibia and the femur are believed to have an effect on patellofemoral mechanics and therefore PFPS. The current work is to explore the various effects of neighboring bone rotation on the various measurements of patellar tilting, through an axial computed tomography study, to help selecting a better parameter for patella tilting and implement a rationale for the necessary intervention at controlling the limb alignment in the therapeutic regime of PFPS. METHODS: Forty seven patients (90 knees), comprising of 34 females and 11 males, participated in this study. Forty five knees, from randomly selected sides of bilaterally painful knees and the painful knees of unilaterally painful knees, were enrolled into the study. From the axial CT images in the subject knees in extension with quadriceps relaxed, the measurements of femoral rotation, tibial rotation, femoral rotation relative to tibia, and 3 parameters for patella tilting were obtained and analyzed to explore the relationship between the different measurements of patella tilt angle and the measurements of its neighboring bone rotation (femoral, tibial rotation, and femoral rotation relative to tibia). RESULTS: The effect of femoral, tibial rotation, and femoral rotation relative to tibia on patella tilting varied with the difference in the way of measuring the patella tilt angle. Patella tilt angle of Grelsamer increased with increase in femoral rotation, and tibial rotation. Patella tilt angle of Sasaki was stationary with change in femoral rotation, tibial rotation, or femoral rotation relative to tibia. While, modified patella tilt angle of Fulkerson decreased with increase in femoral rotation, tibial rotation, or femoral rotation relative to tibia. CONCLUSION: The current study has demonstrated various effects of regional bony alignment on the different measurements of the patellar tilt. And the influence of bony malalignment on the patellar tilt might draw a clinical implication that patellar malalignment can not be treated, separately, independent of the related limb alignment. This clinical implication has to be verified by further works, with a comprehensive evaluation of the various treatments of patellar malalignment.

Investigation of clinical effects of high- and low-resistance training for patients with knee osteoarthritis: a randomized controlled trial.

BACKGROUND AND PURPOSE: Muscle strength training is important for people with knee osteoarthritis (OA). High-resistance exercise has been demonstrated to be more beneficial than low-resistance exercise for young subjects. The purpose of this study was to compare the effects of high- and low-resistance strength training in elderly subjects with knee OA. SUBJECTS AND METHODS: One hundred two subjects were randomly assigned to groups that received 8 weeks of high-resistance exercise (HR group), 8 weeks of low-resistance exercise (LR group), or no exercise (control group). Pain, function, walking time, and muscle torque were examined before and after intervention. RESULTS: Significant improvement for all measures was observed in both exercise groups. There was no significant difference in any measures between HR and LR groups. However, based on effect size between exercise and control groups, the HR group improved more than the LR group. DISCUSSION AND CONCLUSION: Both high- and low-resistance strength training significantly improved clinical effects in this study. The effects of high-resistance strength training appear to be larger than those of low-resistance strength training for people with mild to moderate knee OA, although the differences between the HR and LR groups were not statistically significant.