Efficacy of isokinetic exercise on functional capacity and pain in patellofemoral pain syndrome

OBJECTIVE: To assess the effect of an isokinetic exercise program on symptoms and functions of patients with patellofemoral pain syndrome. DESIGN: A total of 22 consecutive patients with the complaint of anterior knee pain who met the inclusion criteria were recruited to assess the efficacy of isokinetic exercise on functional capacity, isokinetic parameters, and pain scores in patients with patellofemoral pain syndrome. A total of 37 knees were examined. Six-meter hopping, three-step hopping, and single-limb hopping course tests were performed for each patient with the measurements of the Lysholm scale and visual analog scale. Tested parameters were peak torque, total work, average power, and endurance ratios. RESULTS: Statistical analyses revealed that at the end of the 6-wk treatment period, functional and isokinetic parameters improved significantly, as did pain scores. There was not statistically significant correlation between different groups of parameters. CONCLUSION: The isokinetic exercise treatment program used in this study prevented the extensor power loss due to patellofemoral pain syndrome, but the improvement in the functional capacity was not correlated with the gained power.     

铅球运动员主要关节等速肌力配布特征

背景：目前,国内外利用等速仪器针对铅球运动主要环节肌肉力量特征方面研究的文献较少。目的：查找铅球运动员不同速度下各主要环节肌力配布特征和存在的不足。方法：利用德国ISOMED2000等速肌力测试系统,对第十一届全运会男子铅球冠军膝关节、髋关节、腰背环节和肩关节进行慢速60（°）/s和快速180（°）/s等速测试。结果与结论：1膝关节慢速左右侧屈伸肌比值为25.6%、39.4%,快速屈伸肌比值为28.5%、29.8%,屈肌群肌力较小。2髋关节在快、慢速时,右侧伸肌群分别为左侧的2.11和1.87倍,屈肌群为1.25和1.64倍,右髋非常显著性大于左髋。3腰背环节慢速屈伸肌比值为93.3%,快速测试屈伸肌比值为84.3%。4肩关节自然位屈伸,慢速屈伸肌力右肩分别为左肩的1.27和1.34倍,快速为左肩的1.40和1.92倍。5各环节根据人体模型相对质量按膝关节为基准膝、髋、躯干、肩为1∶2.38∶3.30∶0.70。结果表明：1膝关节屈伸肌群绝对肌力、快速屈肌群肌力均较弱,肌群配备不合理。2躯干肌力在右侧最大力量伸肌群、左右侧快速伸肌群非常薄弱,增加腰背肌力伸肌训练,特别是慢速和快速肌肉力量和伸展性训练。3右侧各环节伸肌群薄弱,加强右肩伸肌群的绝对肌肉力量。     

股四头肌绳肌等速肌力测试的效度研究

了解Ｃｙｂｅｘ３３０型等速功能评定装置是否能有效反映肌力。方法：按骨骼肌肌力与总的肌纤维横断面积成比例的特性，选用ＣＴ成像技术测量产力肌的横断面积和ＣＴ值，对抽测的绳肌和股四头肌的峰值转矩、面积和ＣＴ值进行对比研究。结果：①所有受试者诸肌的各峰值转矩与面积的相关系数为０．４８－０．８０，相关均有显著性或非常显著性；②正常人所测肌的各峰转矩与ＣＴ值的相关系数为０．０２－０．５０，相关均无显著性；③患者除股四头肌在３００°／ｓ运动时峰值转矩与Ｃ４值的相关无显著性外，其余各峰值转矩与ＣＴ值的相关系数为０．４６－０．６１，相关有显著性或非常显著性；④在正常人中，虽然上述指标大多数为优势侧大于非优势侧，但双侧差异均无显著性，而患者健侧的各项指标均大于患侧，差异有显著性和非常显著性。结论：用此装置所测试的等速肌力符合产力肌肉横断面积的变化，他不仅能有效地评定肌力，而且能反映用徒手肌力测试观察不到的肌力变化，可以作为客观评定临床和康复治疗效果及康复医学等研究的工具。     

踝关节位置觉和肌肉力觉的重测信度

背景:目前对于踝关节矢状面内本体感觉的研究较为缺乏,踝关节本体感觉的测试没有统一的标准.目的:分析踝关节矢状面内运动位置觉和力觉的重测信度.方法:踝关节位置觉采用对踝关节跖屈5°的被动定位被动复位能力进行测试,肌肉力觉采用受试者踝关节对跖屈肌群25%最大等长峰值力矩值的复制能力进行测试;运用组内相关系数和测量的标准误来判断位置觉和力觉重复测量结果的一致性程度.结果与结论:用来衡量关节位置觉和肌肉力觉的可变误差和绝对误差的组内相关系数均大于0.75,而且测量的标准误相对较小.常数误差的组内相关系数均小于0.75,而且测量的标准误相对较大.提示用来衡量位置觉和力觉的常数误差重测信度较差,用来衡量位置觉和力觉的可变误差和绝对误差重测信度较好.     

Correlation of pain sensitization with muscle strength and angular kinematics in women with patellofemoral pain

BackgroundPatellofemoral pain has a poor long-term prognosis, which can be explained by a pain sensitization process. The pain sensitization process may be related to the increase of stress in the patellofemoral joint that is already associated with kinematic alterations and weakness in the musculature of the hip and knee.MethodsWere compared the pressure pain threshold, temporal summation, conditioned pain modulation, angular kinematics, and muscle strength between 26 patellofemoral pain and 24 asymptomatic women and then correlated pain sensitization variables with biomechanical variables in pain group. The pressure pain threshold was determined on seven points of the knee, tibialis anterior muscle, and elbow. Ten consecutive stimuli were performed for temporal summation, and cold water was used as the conditioning stimulus for conditioned pain modulation. The strength of hip and knee muscles was determined using a manual dynamometer. Three-dimensional kinematics were evaluated during the lateral step down, considering peak and excursion values of the movement and the Movement Deviation Profile.FindingsThe pressure pain threshold of the elbow (2.13 [1.84–2.41] vs. 1.63 [1.25–2] kg/cm²), all sites of the knee were lower, as well as the Movement Deviation Profile was higher (9.33 [9.20–9.46] vs. 12.43 [12.1–12.75]) in the pain group. No difference in temporal summation, conditioned pain modulation, muscle strength and discrete kinematic values were found. No significant correlation was found between the Movement Deviation Profile and pressure pain threshold.InterpretationBiomechanical factors, pain processing, and modulation in women with patellofemoral pain, when different from asymptomatic individuals, are not necessarily associated.     

限弧等速肌力训练对于髌股关节炎髌骨轨迹的影响

目的:探讨不同限弧等速肌力训练对髌股关节炎患者髌骨轨迹的影响。方法:诊断为髌股关节炎患者60例,按接诊顺序分为A组(0°～30°)、B组(30°～60°)和C组(60°～90°)不同角度限弧运动训练组,每组各20例,采用德国ISOMED 2000等速肌力训练系统按分组对患者膝关节周围肌肉进行4周的限弧等速肌力训练。训练前、后拍摄膝关节负重正侧位及屈膝45°轴位片,测量髌骨轨迹参数(即髌股指数、外侧髌股角、髌骨合适角);记录每个膝关节的等速肌力测定值,即峰力矩(PT)、总功(TW)及平均功率(AP);采用西安大略和麦克马斯特大学骨关节炎指数(WOMAC)(包括疼痛、僵硬、日常功能)评定膝关节功能。结果:训练4周后,A组髌股指数、髌骨合适角较训练前明显降低,外侧髌股角较训练前明显提高(P<0.05);A、B、C组峰力矩PT、总功TW及平均功率AP值均较训练前明显提高(P<0.05);WOMAC评分比较,A组疼痛、日常功能评分较训练前明显降低(P<0.05)。训练后,髌骨轨迹参数比较:髌股指数、髌骨合适角A组明显低于B、C组(P<0.05),外侧髌股角明显高于B、C组...     

The role of muscle strength & activation patterns in patellofemoral pain

BackgroundTo investigate the extent to which quadriceps muscle activation and strength are responsible for patellofemoral pain.MethodsA pain on–off switch system synchronized with a force transducer and surface electromyography was utilized on 32 volunteer patellofemoral pain patients during maximal isometric and squat exercises.FindingsThere were 26 patients out of the 32 tested who complained of pain during the squat or isometric test, of these 20 subjects presented a significant advantage for the vastus lateralis compared to the vastus medialis obliquis activation and 12 patients had decreased quadriceps strength of the symptomatic compared to the non symptomatic leg. All patients who demonstrated weak vastus medialis obliquis activation during the isometric exercise possessed the same symptoms during the squat. On the other hand, 9 patients who showed diminished vastus medialis obliquis activation during the squat displayed equal activation between the vastus medialis obliquis and the vastus lateralis during the isometric task. With regard to the timing for the onset of muscle activation, there were only 4 patients who had a difference (P = 0.03) between the symptomatic (0.042 s) and non-symptomatic legs (0.011 s).InterpretationCauses for patellofemoral pain vary and are not necessarily a result of quadriceps strength deficit or vastus medialis obliquis activation weakness. Patellofemoral pain patients who possess lower vastus medialis obliquis activation compared to the vastus lateralis do not necessarily have quadriceps weakness while patients presenting with quadriceps strength deficits do not always have an imbalance between vastus medialis obliquis and vastus lateralis activation.     

Subclinical neck pain and the effects of cervical manipulation on elbow joint position sense

Objective

The objectives of this study were to investigate whether elbow joint position sense (JPS) accuracy differs between participants with a history of subclinical neck pain (SCNP) and those with no neck complaints and to determine whether adjusting dysfunctional cervical segments in the SCNP group improves their JPS accuracy.

Method

Twenty-five SCNP participants and 18 control participants took part in this pre-post experimental study. Elbow JPS was measured using an electrogoniometer (MLTS700, ADInstruments, New Zealand). Participants reproduced a previously presented angle of the elbow joint with their neck in 4 positions: neutral, flexion, rotation, and combined flexion/rotation. The experimental intervention was high-velocity, low-amplitude cervical adjustments, and the control intervention was a 5-minute rest period. Group JPS data were compared, and it was assessed pre and post interventions using 3 parameters: absolute, constant, and variable errors.

Results

At baseline, the control group was significantly better at reproducing the elbow target angle. The SCNP group's absolute error significantly improved after the cervical adjustments when the participants' heads were in the neutral and left-rotation positions. They displayed a significant overall decrease in variable error after the cervical adjustments. The control group participants' JPS accuracy was worse after the control intervention, with a significant overall effect in absolute and variable errors. No other significant effects were detected.

Conclusion

These results suggest that asymptomatic people with a history of SCNP have reduced elbow JPS accuracy compared to those with no history of any neck complaints. Furthermore, the results suggest that adjusting dysfunctional cervical segments in people with SCNP can improve their upper limb JPS accuracy.     

Effects of patellar taping on knee joint proprioception in patients with patellofemoral pain syndrome

The aim of this study was to assess the effect of patellar taping of the proprioceptive status of patients with patellofemoral pain syndrome (PFPS). A total of 32 subjects (18 males, 14 females of age 31.9 +/- 11.2, body mass index 25.8 +/- 5.3) with PFPS were tested for Joint Position Sense (JPS) using a Biodex dynamometer. Outcomes of interest were the absolute error (AE), the variable error (VE) and the relative error (RE) of the JPS values for both active (AAR) and passive (PAR) angle reproduction at an angular velocity of 2 degrees /s with a start angle at 90 degrees and target angles of 60 degrees and 20 degrees . Taping was applied in random order across the patella of each subject with each of the subjects acting as their own internal control. Results indicated initially that application of patellar tape did not enhance and in some cases worsened the JPS of the subjects (P > 0.05). However, when the subjects' proprioceptive status was graded according to their closeness to the target angles into 'good' (5 degrees , N = 10) and 'poor' ( > 5 degrees , N = 22) taping enhanced nearly all values of those with 'poor' proprioception, with AE at 20 degrees to statistical significance (P = 0.021). In conclusion, this study has shown that patellar taping did not improve the AAR and PAR JPS tests of a whole sample of 32 PFPS patients. It also has shown that a subgroup of PFPS patients with poor proprioception may exist and be helped by patellar taping.     

Electromyographic biofeedback-controlled exercise versus conservative care for patellofemoral pain syndrome.

OBJECTIVE: To determine the effects of electromyographic biofeedback treatment in patients with patellofemoral pain syndrome. DESIGN: Randomized controlled trial. SETTING: A physical medicine and rehabilitation department in a research hospital of a university referral center. PATIENTS: Sixty patients with patellofemoral pain syndrome. Patients were randomly placed into 2 groups: biofeedback group (n = 30) and a control group (n = 30). INTERVENTION: The biofeedback group received electromyographic biofeedback training and a conventional exercise program, whereas the control group received a conventional exercise program only. MAIN OUTCOME MEASURES: Maximum and mean contraction values of the vastus medialis and the vastus lateralis muscles were assessed with the biofeedback device. Pain and functional status of the patients were measured by a visual analog scale (VAS) and the Functional Index Questionnaire (FIQ), respectively. RESULTS: Contraction values improved significantly at the end of the first month, compared with the pretreatment values in both groups. Mean contraction values in the biofeedback group of the vastus medialis muscles in all 3 monthly measurements, and the vastus lateralis muscles at the end of the first month, were significantly higher than those of the control group. Significant improvements were shown for both the VAS and the FIQ in both groups. Monthly follow-ups showed no VAS and FIQ differences between the groups. CONCLUSION: Electromyographic biofeedback treatment did not result in further clinical improvement when compared with a conventional exercise program in patients with patellofemoral pain syndrome.     

健康年轻人腕关节等速肌力测试的测试者内信度和间信度

背景:越来越多研究运用等速肌力测试评估腕关节肌力,但未见有腕关节等速肌力测试的测试者内和测试者间信度报道。目的:观察健康受试者等速肌力测试腕关节屈伸肌力的峰力矩和总功的重测信度。方法:28例健康受试者随机等分为2组。第1次测试2组分别由测试者A、B在60(°)/s和180(°)/s角速度下测试。第2次测试,2组均由测试者B完成测试。结果与结论:在60(°)/s和180(°)/s下,腕关节屈肌和伸肌的峰力矩和总功的测试者内重测信度为0.65-0.95,测试者间重测信度为0.70-0.95。在低速和高速下健康受试者腕关节等速肌力测试的峰力矩和总功的重测信度为好到极好。     

Management of patellofemoral pain syndrome

Patellofemoral pain syndrome (PFPS) is the most common cause of knee pain in the outpatient setting. It is caused by imbalances in the forces controlling patellar tracking during knee flexion and extension, particularly with overloading of the joint. Risk factors include overuse, trauma, muscle dysfunction, tight lateral restraints, patellar hypermobility, and poor quadriceps flexibility. Typical symptoms include pain behind or around the patella that is increased with running and activities that involve knee flexion. Findings in patients with PFPS range from limited patellar mobility to a hypermobile patella. To confirm the diagnosis, an examination of the knee focusing on the patella and surrounding structures is essential. For many patients with the clinical diagnosis of PFPS, imaging studies are not necessary before beginning treatment. Radiography is recommended in patients with a history of trauma or surgery, those with an effusion, those older than 50 years (to rule out osteoarthritis), and those whose pain does not improve with treatment. Recent research has shown that physical therapy is effective in treating PFPS. There is little evidence to support the routine use of knee braces or nonsteroidal anti-inflammatory drugs. Surgery should be considered only after failure of a comprehensive rehabilitation program. Educating patients about modification of risk factors is important in preventing recurrence.     

Effect of isotonic and isokinetic exercise on muscle activity and balance of the ankle joint

[Purpose] This study was performed to examine how the balance of lower limbs and the muscle activities of the tibialis anterior (TA), the medial gastrocnemius (GCM), and the peroneus longus (PL) are influenced by isotonic and isokinetic exercise of the ankle joint. [Subjects] The subjects of this study were healthy adults (n=20), and they were divided into two groups (isotonic=10, isokinetic=10). [Methods] Isotonic group performed 3 sets of 10 contractions at 50% of MVIC and Isokinetic group performed 3 sets of 60°/sec. Muscle activity was measured by EMG and balance was measured by one-leg standing test. [Results] For muscle activity, a main effect of group was found in the non-dominant TA, and the dominant TA, GCM and PL. For balance, a main effect of time was found in both groups for the sway area measured support was provided by the non-dominant side. [Conclusion] In terms of muscle activity, the two groups showed a significant difference, and the isokinetic group showed higher muscle activities. In terms of balance, there was a significant difference between the pre-test and the post-test. The results of this study may help in the selection of exercises for physical therapy, because they show that muscle activity and balance vary according to the type of exercise.Key words: Isotonic, Isokinetic, Balance     

Quadriceps muscle activity in women runners with and without patellofemoral pain syndrome.

The purpose of this study was to determine whether there was a difference in the electromyographic (EMG) patterns of the quadriceps muscles in women runners diagnosed with patellofemoral pain syndrome (PFPS) compared to the quadriceps activity of women runners free of knee pain and with normal lower extremity alignment. Linear envelope EMGs from vastus medialis, vastus lateralis, and rectus femoris, together with a footswitch signal, were recorded as each subject ran on a treadmill at 80% of their normal running pace and at 12km/h. Each stride period was normalized to 100%, then the linear envelopes for ten trials were ensemble averaged to achieve a mean ensemble for each muscle from each subject. Subsequently, the ensembles for each subject were normalized by dividing by the maximum EMG per cycle; they were then averaged across subjects to obtain the grand mean ensembles of each muscle for each group. Comparisons between the experimental and control groups at both speeds showed that nowhere during the stride cycle did the mean EMG levels of the two groups differ by more than two standard deviations. It was concluded that any changes in the running pattern of the runners with patellofemoral pain syndrome could not be detected by changes in the EMG patterns.     

Gluteal muscle activation during running in females with and without patellofemoral pain syndrome

Background

Hip and knee joint motion in the transverse and frontal plane during running may increase patellofemoral joint stress and contribute to the etiology of patellofemoral joint pain. We evaluated the association between these kinematics and the magnitude and timing of gluteus medius and maximus activity during running in females with patellofemoral pain. We also compared the magnitude and timing of gluteal muscle activity during running between females with and without patellofemoral pain.

Methods

Twenty females with patellofemoral pain and twenty females without knee pain participated in this study. Three-dimensional running kinematics, gluteus medius and gluteus maximus onset time, activation duration, mean activation level, and peak activation level were recorded simultaneously. Gluteal muscle timing and activation level were compared between groups using independent t-tests. The association of gluteal muscle activation parameters running kinematics in females with patellofemoral pain was quantified using Pearson correlation coefficients.

Findings

Females with patellofemoral pain demonstrated delayed (P = 0.028, effect size = 0.76) and shorter (P = 0.01, effect size = 0.88) gluteus medius activation than females without knee pain during running. The magnitude and timing of gluteus maximus activation was not different between groups. Greater hip adduction and internal rotation excursion was correlated with later gluteus medius and gluteus maximus onset, respectively.

Interpretation

Neuromuscular control differences of the gluteal muscles appear to exist among females with patellofemoral pain during running. Interventions to facilitate earlier activation of these muscles may be warranted among females with patellofemoral pain who demonstrate altered running kinematics.     

Hamstring length in patellofemoral pain syndrome

Objectives

To investigate whether there was a difference in hamstring length between patients with patellofemoral pain syndrome and healthy asymptomatic controls aged 18 to 35 years.

Design

A cross-sectional observational study measuring hamstring length in patients and asymptomatic controls.

Setting

Hospital physiotherapy department.

Participants

Two groups were tested; one group diagnosed with patellofemoral pain syndrome (mean age 27 years, n = 11, six males, five females) and one group of asymptomatic controls (mean age 25 years, n = 25, 13 males, 12 females).

Main outcome measures

Hamstring length was evaluated using the passive knee extension method to measure popliteal angle.

Results

The mean (standard deviation) values for hamstring length were 145.6 (8.7)° for patients with patellofemoral pain syndrome and 153.7 (10.1)° for the asymptomatic controls. The mean (95% confidence interval) difference between the groups was 8.0 (0.8 to 15.1)°, and analysis with a t-test revealed that this was statistically significant (P < 0.05).

Conclusions

This study found that patients with patellofemoral pain had shorter hamstring muscles than asymptomatic controls. It is not clear whether this is a cause or effect of the condition. Further research is suggested to study how hamstring length changes with rehabilitation, and the relationship with pain.     

Physical examination and patellofemoral pain syndrome

Patellofemoral pain syndrome, which accounts for 25% of all sports-related knee injuries, is multifactorial in origin. A combination of variables, including abnormal lower limb biomechanics, soft-tissue tightness, muscle weakness, and excessive exercise, may result in increased cartilage and subchondral bone stress, patellofemoral pain, and subtle or more overt patellar maltracking. Because of the multiple forces affecting the patellofemoral joint, the clinical evaluation and treatment of this disorder is challenging. An extensive search of the literature revealed no single gold-standard test maneuver for that disorder, and the reliability of the maneuvers described was generally low or untested. An abnormal Q-angle, generalized ligamentous laxity, hypomobile or hypermobile tenderness of the lateral patellar retinaculum, patellar tilt or mediolateral displacement, decreased flexibility of the iliotibial band and quadriceps, and quadriceps, hip abductor, and external rotator weakness were most often correlated with patellofemoral pain syndrome.     

Effects of step length on patellofemoral joint stress in female runners with and without patellofemoral pain

Background

Patellofemoral pain is common among runners and is frequently attributed to increased patellofemoral joint stress. The purpose of our study was to examine the effects of changing step length during running on patellofemoral joint stress per step and stress per mile in females with and without patellofemoral pain.

Methods

Ten female runners with patellofemoral pain and 13 healthy female runners performed running trials at 3.7 m/s in three conditions: preferred step length, at least + 10% step length, and at least − 10% step length. Knee flexion angles and internal knee extension moments served as inputs for a biomechanical model to estimate patellofemoral joint stress per step. We also estimated total patellofemoral joint stress per mile based on the number of steps necessary to run a mile during each condition.

Findings

Patellofemoral joint stress per step increased 31% in the long step length condition (P < .001) and decreased 22.2% in the short step length condition (P < .001). Despite the inverse relationship between step length and number of steps required to run a mile, patellofemoral joint stress per mile increased 14% in the long step length condition (P < .001) and decreased 7.5% in the short step length condition (P < .001).

Interpretation

These results suggest a direct relationship between step length and patellofemoral joint loads. Total stress per mile experienced at the patellofemoral joint decreased with a short step length despite the greater number of steps necessary to cover this distance. These findings may have relevance with respect to both prevention and treatment of patellofemoral joint pain.     

闭链离心等张训练对髌股疼痛综合征患者膝关节功能的影响

目的:探讨闭链离心等张训练对髌股疼痛综合征(PFPS)患者膝关节功能的疗效。方法:选取33例符合纳入排除标准的髌股疼痛综合征患者,采用随机数字表法分成试验组(n=17)和对照组(n=16);试验组采用常规康复训练+闭链离心等张训练,对照组仅进行常规康复训练。两组患者在治疗前、治疗8周采用视觉模拟评分法(VAS)评定患者疼痛程度、等速肌力测定膝伸屈肌群肌力、膝关节Kujala评分评价膝关节功能以及SF-36评估生存质量。结果:两组治疗8周后VAS评分低于治疗前(P0.05)、Kujala评分、60°/s速度下膝伸屈肌群峰力矩、SF-36中生理职能、躯体疼痛、一般健康状况改善,与治疗前比较差异有显著性意义(P0.05)。8周治疗后,试验组VAS评分低于对照组(P0.05)、Kujala评分、60°/s速度下膝伸屈肌群峰力矩及SF-36中生理职能、健康变化均高于对照组(P0.05)。结论:常规康复训练的基础上结合闭链离心等张训练能进一步缓解髌股疼痛综合征患者膝关节疼痛、增强肌力、提高生活满意度,建议可以作为PFPS康复训练的一部分,值得临床应用及推广。