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.

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.

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.

Effects of anterolateral minimally invasive surgery in total hip arthroplasty on hip muscle strength, walking speed, and functional score.

We conducted this study to observe the difference in muscle strength and walking speed between patients who underwent total hip arthroplasty (THA) in whom an anterolateral mini-incision technique was used and those in whom a conventional approach was used. Fifty-three patients who underwent a mini-incision THA were matched by diagnosis, sex, age, period elapsed since surgery (which ranged from 6 months to 4 years), weight, and height to 53 patients who underwent THA using the conventional anterolateral approach. During the first year after surgery, patients with the mini-incision THA had significantly better hip muscle strength, walking speed, and functional score (P < .05). At 1 year, the performance characteristics studied were statistically equivalent (P > .05). Although the mini-incision technique is more difficult than the conventional technique, its use by experienced surgeons can produce quicker short-term recovery.

Comparison of proprioceptive functions between computerized proprioception facilitation exercise and closed kinetic chain exercise in patients with knee osteoarthritis.

AIM: The aim of this study was to compare proprioceptive function between computerized proprioception facilitation exercise (CPFE) and closed kinetic chain exercise (CKCE) for knee osteoarthritis. DESIGN: Randomized-controlled. SETTING: Kinesiology laboratory. PATIENTS: Eighty-one patients with bilateral knee osteoarthritis were randomly assigned to CPFE, CKCE, and control groups. INTERVENTION: Both exercise groups underwent an 8-week program of three sessions per week. The control group received no training. The CPFE program included a 20-min computer game to be played by the trained foot of the subject. CKCE included 10 sets of 10 repetitions of repeated knee extension and flexion with resistance of 10-25% of body weight. MAIN OUTCOME MEASURES: Absolute reposition error, functional score, walking speed, and knee muscle strength were assessed with an electrogoniometer, the physical function subscale of Western Ontario and McMaster Osteoarthritis Index, a CASIO stopwatch, and a Cybex 6000 dynamometer before and after the 8-week period. RESULTS: The results of this study showed that both CPFE and CKCE were effective in improving joint position sense, functional score, walking speed, and muscle strength. Furthermore, CKCE showed greater effect in increasing knee extensor torque in patients with knee osteoarthritis. CONCLUSION: Clinical effects of CPFE were the same as those of CKCE except for knee extensor torque. The increase in knee extensor torque in CPFE patients was not as great as that seen in CKCE patients.

Effects of age and sex on the results of an ankle plantar-flexor manual muscle test.

BACKGROUND AND PURPOSE: The ability to perform 20 or more one-leg heel-rises is considered a "normal" grade for muscle strength (force-generating capacity of muscle) of the ankle plantar flexors, regardless of age and sex. Because muscle strength is closely related to age and sex, the "normal" test criterion was re-evaluated in different groups categorized by age and sex. SUBJECTS AND METHODS: One hundred eighty sedentary volunteers (21-80 years of age) without lower-limb lesions performed as many repetitions of one-leg heel-rise as possible. Lunsford and Perry criteria were used to determine completion of the test. RESULTS: The age and sex of the participants influenced the maximal repetitions of heel-rise, and the repetitions decreased with age and in female subjects. DISCUSSION AND CONCLUSION: The muscle strength of the ankle plantar flexors, as measured by manual muscle testing, varied with age and sex. Clinicians should consider the variances of age and sex when they perform manual muscle testing of the ankle plantar flexors.