Gait Analysis for Evaluating the Relationship Between Increased Signal Intensity on T2-Weighted Magnetic Resonance Imaging and Gait Function in Cervical Spondylotic Myelopathy

Kim CR, Yoo JY, Lee SH, Lee DH, Rhim SC. Gait analysis for evaluating the relationship between increased signal intensity on T2-weighted magnetic resonance imaging and gait function in cervical spondylotic myelopathy.

Objective

To determine relationships between increased signal intensity (ISI) on T2-weighted cervical spine magnetic resonance imaging (MRI) and parameters of gait analysis in patients with cervical spondylotic myelopathy (CSM).

Design

Retrospective comparative study.

Setting

Gait analysis laboratory.

Participants

Patients (N=36) who undertook cervical laminectomy or laminoplasty because of CSM.

Interventions

Not applicable.

Main Outcome Measures

Subjects were evaluated by using the modified Japanese Orthopaedic Association (JOA) scale, the Nurick scale, cervical spine MRI, and gait analysis. Two radiologists classified patients into 3 groups: intense, faint, and no ISI.

Results

Relative to patients without ISI, those with ISI showed significantly slower gait speed, longer step time, decreased single-limb support time, increased double-limb support time, and limited range of motion of knee and ankle (P<.05). Increased intensity tended to correlate with poor gait function including slower gait speed, longer step time, decreased single-limb support time, and increased double-limb support time. The modified JOA and Nurick scale did not correlate with ISI.

Conclusions

In patients with CSM who received surgical treatment, more intense ISI on T2-weighted MRI correlated preoperatively with increased difficulties in gait function. Gait analysis may be a useful tool for evaluating gait functions in cervical myelopathy.     

Is there altered activity of the extensor muscles in chronic mechanical neck pain? A functional magnetic resonance imaging study

O'Leary S, Cagnie B, Reeve A, Jull G, Elliott JM. Is there altered activity of the extensor muscles in chronic mechanical neck pain? A functional magnetic resonance imaging study.

Objective

To compare the pattern of neck extensor muscle use in participants with chronic mechanical neck pain to that of healthy controls during 2 different extension exercises by use of muscle functional magnetic resonance imaging (mfMRI).

Design

Cross-sectional.

Setting

University laboratory.

Participants

Data recorded from subjects with chronic mechanical neck pain (n=12; 10 women, 2 men) were compared with previously recorded data from healthy subjects (n=11; 7 men, 4 women).

Interventions

Not applicable.

Main Outcome Measures

mfMRI measures of shifts in T2 relaxation were made for the multifidus, semispinalis cervicis, semispinalis capitis, and splenius capitis muscles, at C2-3, C5-6, and C7-T1 levels, prior and immediately after 2 different exercises: cervical extension in craniocervical neutral (CCN) and cervical extension in craniocervical extension. T2 shift values (difference between pre- and postexercise T2 relaxation values) for each muscle and exercise condition were used for analysis.

Results

While there were observed differences in differential activation of the extensor muscles in participants with mechanical neck pain compared with controls, these differences were only evident for the CCN exercise condition and were only observed for 3 out of the 7 muscle regions of interest during this exercise.

Conclusions

Results of this study suggest some alteration in the differential activation of the cervical extensors in patients with mechanical neck pain and indicate that further investigation of this muscle group in mechanical neck pain disorders is warranted.     

Prediction of memory rehabilitation outcomes in traumatic brain injury by using functional magnetic resonance imaging

Strangman GE, O'Neil-Pirozzi TM, Goldstein R, Kelkar K, Katz DI, Burke D, Rauch SL, Savage CR, Glenn MB. Prediction of memory rehabilitation outcomes in traumatic brain injury by using functional magnetic resonance imaging.

Objective

To evaluate the ability of functional magnetic resonance imaging (fMRI) measures collected from people with traumatic brain injury (TBI) to provide predictive value for rehabilitation outcomes over and above standard predictors.

Design

Prospective study.

Setting

Academic medical center.

Participants

Persons (N=54) with TBI greater than 1 year postinjury.

Intervention

A novel 12-session group rehabilitation program focusing on internal strategies to improve memory.

Main Outcome Measure

The Hopkins Verbal Learning Test−Revised (HVLT-R) delayed recall score.

Results

fMRI measures were collected while participants performed a strategically directed word memorization task. Prediction models were multiple linear regressions with the following primary predictors of outcome: age, education, injury severity, preintervention HVLT-R, and task-related fMRI activation of the left dorsolateral and left ventrolateral prefrontal cortex (VLPFC). Baseline HVLT-R was a significant predictor of outcome (P=.007), as was injury severity (for severe vs mild, P=.049). We also found a significant quadratic (inverted-U) effect of fMRI in the VLPFC (P=.007).

Conclusions

This study supports previous evidence that left prefrontal activity is related to strategic verbal learning, and the magnitude of this activation predicted success in response to cognitive memory rehabilitation strategies. Extreme under- or overactivation of VLPFC was associated with less successful learning after rehabilitation. Further study is necessary to clarify this relationship and to expand and optimize the possible uses of functional imaging to guide rehabilitation therapies.     

Age-Related Differences in Lower-Limb Muscle Cross-Sectional Area and Torque Production in Boys With Duchenne Muscular Dystrophy

Mathur S, Lott DJ, Senesac C, Germain SA, Vohra RS, Sweeney HL, Walter GA, Vandenborne K. Age-related differences in lower-limb muscle cross-sectional area and torque production in boys with Duchenne muscular dystrophy.

Objective

To examine the relationship between lower-extremity muscle cross-sectional area, muscle strength, specific torque, and age in ambulatory boys with Duchenne muscular dystrophy (DMD) compared with controls.

Design

Observational cross-sectional study.

Setting

University research setting.

Participants

Volunteer sample of boys with DMD (n=22) and healthy control boys (n=10), ages 5 through 14 years.

Interventions

Not applicable.

Main Outcome Measures

Maximal muscle cross-sectional area (CSA_max) assessed by magnetic resonance imaging of quadriceps, plantarflexors (PFs) and dorsiflexors (DFs), peak isometric torque from dynamometry, and timed functional tests.

Results

The average CSA_max of the triceps surae muscle group was approximately 60% higher in boys with DMD compared with controls (39.1±13.6 cm² vs 24.5±9.3 cm²; P=.002), while the tibialis anterior muscle showed age-appropriate increases in CSA_max. The increase in quadriceps CSA_max was also distinctly different in boys with DMD compared with controls. Specific torque (ie, peak torque/CSA_max) was impaired in all 3 muscles groups, with the knee extensor (KE) and PF muscles showing 4-fold, and the DF muscles 2-fold, higher values in controls compared with boys with DMD. Large age-related gains in specific torque were observed in all 3 muscle groups of control subjects, which were absent in ambulatory boys with DMD. Correlations were observed between performance on functional tasks and quadriceps and PF torque production (r=−.45 to −.57, P<.05), but not with DF strength.

Conclusions

Age-related changes in muscle cross-sectional area and specific torque production in lower-extremity muscles showed distinctly different patterns in the KE, PF, and DF muscles of boys with DMD compared with controls.     

Upper Extremity Kinematics and Muscle Activation Patterns in Subjects With Facioscapulohumeral Dystrophy

Objective

To compare the kinematics and muscle activity of subjects with facioscapulohumeral dystrophy (FSHD) and healthy control subjects during the performance of standardized upper extremity tasks.

Design

Exploratory case-control study.

Setting

A movement laboratory.

Participants

Subjects (N=19) with FSHD (n=11) and healthy control subjects (n=8) were measured.

Interventions

Not applicable.

Main Outcome Measures

Kinematic data were recorded using a 3-dimensional motion capturing system. Muscle activities, recorded using electromyography, were obtained from 6 superficial muscles around the glenohumeral joint. Shoulder elevation and elbow flexion angles, and maximum electromyographic activity during the movements as a percentage of maximum voluntary contraction (MVC) were calculated.

Results

Kinematic differences between the FSHD group and the healthy control group were found in the shoulder elevation angle during single shoulder movements and both reaching tasks. In general, subjects with FSHD had higher percentages of muscle activation. The median activity of the trapezius was close to the MVC activity during the single shoulder movements. Moreover, deltoid and pectoralis muscles were also highly active.

Conclusions

Higher activation of the trapezius in subjects with FSHD indicates a mechanism that could help relieve impaired shoulder muscles during arm elevation around shoulder height. Compared with healthy subjects, persons with FSHD activated their shoulder muscles to a greater extent during movements that required arm elevation.     

颈椎病脊髓变性期的MRI诊断(附41例报告)

目的：了解脊髓变性期颈椎病的ＭＲＩ表现。方法：研究分析４１例脊髓变性期颈椎病患者的ＭＲＩ图像及临床资料。结果：４１例患者的ＭＲＩ主要表现为椎间盘变性、膨出、脱出、黄韧带肥厚、椎体后缘骨刺形成、后纵韧带钙化、椎体滑脱及脊髓受压、水肿、软化、囊变、出血。结论：ＭＲＩ扫描可为脊髓变性期颈椎病提供可靠的影像学根据，对该期颈椎病的诊断和治疗有重要意义     

Trunk Muscle EMG During Intermediate Pilates Mat Exercises in Beginner Healthy and Chronic Low Back Pain Individuals

Objective

The purpose of this study was to compare the electromyographic pattern of core muscles during intermediate Pilates mat exercises between healthy people and those with low back pain.

Nonuniform activity of human calf muscles during an exercise task

OBJECTIVES: To determine the distribution of leg muscle activity during heel raises using magnetic resonance imaging (MRI) with special emphasis on quantifying activity across multiple axial sections and to determine if there are differences among portions of active muscles. DESIGN: Pre- and postexercise (heel raise) T2-weighted time measurements were assessed by using repeated-measures analysis of variance (ANOVA) and t tests. SETTING: Laboratory and MRI suites. PARTICIPANTS: Eight healthy volunteers. INTERVENTION: Unilateral heel raises every 2 seconds for at least 60 seconds. MAIN OUTCOME MEASURES: Percentage changes from T2-weighted magnetic resonance images of the lateral gastrocnemius, medial gastrocnemius, peroneus longus, soleus, and tibialis anterior muscles, across 10 axial sections, exercise bouts, and a pre-exercise condition. RESULTS: The lateral gastrocnemius, medial gastrocnemius, peroneus longus, and soleus had significantly larger changes in T2 time from pre-exercise times than did the tibialis anterior for whole muscles as determined by using repeated-measures ANOVA and post hoc analyses. The medial gastrocnemius had a significantly greater change in T2 time than the lateral gastrocnemius. Proximal axial sections of the lateral gastrocnemius, medial gastrocnemius, and soleus had significantly larger changes in T2 time from pre-exercise than did distal sections. CONCLUSIONS: This work reconfirms that multiple muscles contribute to plantarflexor forces and additionally shows an apparent proximal versus subvolume organization of activity within the gastrocnemius, medial gastrocnemius, and soleus but not the peroneus longus. This proximal versus distal organization of muscle activity needs further investigation. There may be clinical implications for therapeutic interventions that require accurate placement of electrodes such as biofeedback.     

磁共振成像在小儿脑瘫康复治疗中的应用价值

目的：探讨MRI在儿童脑瘫康复中的应用价值。材料与方法：对88例脑瘫患儿的临床和MRI资料进行回顾性分析,其中痉挛型脑瘫51例,肌张力低下型脑瘫7例,强直型脑瘫4例,共济失调型脑瘫7例,手足徐动型脑瘫4例,混合型脑瘫15例;在脑瘫治疗过程中27例病人进行了MRI随访。结果：MRI显示脑软化灶14例,大脑脑萎缩改变36例,小脑萎缩6例,脑室周围白质软化症17例,脑先天畸形11例。有15例患儿伴有大脑白质的髓鞘发育延迟。MRI显示脑瘫病灶的敏感性为95％。经过综合性康复治疗,患儿脑内的鞘发育延迟和脑萎缩病灶的改善及病人的肢体功能的康复程度之间存在显著性关联（x^2＝6．31,P＜0．05）。结论：MRI对儿童脑瘫的康复治疗具有重要的指导价值。     

A Comparison of the Deep Cervical Flexor Muscle Thicknesses in Subjects with and without Neck Pain during Craniocervical Flexion Exercises

[Purpose] The purpose of the present study was to examine the amount of change in the thicknesses of the deep cervical flexor (DCF) and sternocleidomastoid (SCM) muscles in subjects with neck pain and subjects without neck pain during craniocervical flexion exercise (CCFE). [Subjects] The total number of subjects was 40, comprising 20 in the no-pain group (males 11, females 9) and 20 in the pain group (males 8, females 12). [Methods] Muscle images were obtained using ultrasound, and the thicknesses of the individual muscles were measured using the NIH ImageJ software. [Results] During CCFE, as pressure increased, the no-pain group recruited the DCF more than the pain group, while the pain group recruited the SCM more. [Conclusion] Selective DCF contraction exercises are considered very useful in the treatment of patients with neck pain.Key words: Craniocervical flexion exercise, Deep cervical flexor, Sternocleidomastoid     

Isometric Muscle Function of Knee Extensors and the Relation With Functional Performance in Patients With Stroke

Gerrits KH, Beltman MJ, Koppe PA, Konijnenbelt H, Elich PD, de Haan A, Janssen TW. Isometric muscle function of knee extensors and the relation with functional performance in patients with stroke.

Objective

(1) To examine the isometric strength, speed, and fatigue resistance of the knee extensors of the paretic limb and nonparetic limb in patients with stroke and compare these with able-bodied subjects. (2) To relate the contractile properties with different indices of functional performance.

Design

Case-control study.

Setting

Rehabilitation center research laboratory.

Participants

Eighteen stroke patients and 10 able-bodied controls.

Interventions

Not applicable.

Main Outcome Measures

Maximal voluntary torque (MVT), maximal rate of torque development, time to maximal rate of torque development, half relaxation time (½RT), and fatigue index. Scores on the Functional Ambulation Category scale, Berg Balance Scale, and Rivermead Mobility Index as well as distance walked during the six-minute walk test were obtained.

Results

MVT of the paretic leg was lower than of the nonparetic leg (P<.05), and both limbs had lower MVT than controls (P<.05). Both the paretic and the nonparetic leg showed longer ½RT compared with controls (P<.05). The fatigue index was reduced in the paretic leg (P<.05) but not in the nonparetic leg compared with controls. MVT and fatigue index of the paretic leg were related to indices of functional performance (r=0.49-0.64; P<.05).

Conclusions

Apart from bilateral weakness, knee extensors in patients with stroke showed a lower rate of torque development and relaxation (both paretic and nonparetic leg) and lower fatigue resistance (paretic leg only) than controls, which in part may be a consequence of changes within the muscles. Strength and fatigue resistance relate to functional performance, indicating that these muscle properties should be addressed during rehabilitation. However, future research is needed to elucidate the efficacy of exercise programs.