Alterations In Range Of Motion Research Articles

Utility of cervical dynamic magnetic resonance imaging for evaluating patients with cervical myelopathy: a retrospective study.

Retrospective observational study. This study aimed to evaluate the utility of cervical dynamic magnetic resonance imaging (dMRI) in the assessment of cervical canal stenosis. Cervical spondylotic myelopathy has been intricately linked to both static and dynamic narrowing of the cervical spinal canal. Traditional MRI with the neck in a neutral position fails to identify the dynamic changes and may lead to misdiagnosis. Cervical dMRI is a promising tool for evaluating cervical myelopathy, enabling clinicians to assess spinal cord compression, segmental instability, and alterations in range of motion, often missed on conventional imaging. A retrospective analysis was conducted on 369 patients with symptoms of cervical myelopathy assessed using cervical dMRI. After assessing the subaxial cervical spine at each disc level (C3-T1), significant changes in the degree of central canal stenosis were determined. The appearance and extent of hyperintense lesions on T2-weighted sequences were also noted. Overall, 653/1,845 (35.39%) disc levels showed an increase in stenosis grade on extension MRI, with 168/653 (25.72%) and 180/653 (27.56%) disc levels changing from grades 0/1 to grades 2 and 3, respectively. Moreover, 120/369 (32.52%) patients showed a mean increase of 1.55±0.75 levels of compression on extension MRI when compared to neutral MRI. A fresh-appearing hyperintense lesion was observed in 79 (4.28%) disc levels on flexion MRI, which was not visualized on neutral MRI. Cervical dMRI may help surgeons plan for surgery, discuss the prognosis with the patient, and safeguard themselves from medico-legal issues arising from improper or missed diagnosis and treatment.

Muscle Hypertrophy Response to Range of Motion in Strength Training: A Novel Approach to Understanding the Findings

ABSTRACT One resistance training variable that may be altered to achieve desired outcomes is the range of motion used in training. Generally, the strength and conditioning field has accepted that using a greater range of motion in strength training exercises results in more substantial muscle hypertrophy outcomes. However, this theory has proved to be inconsistently supported in the literature, and to date, no sufficient explanation exists to explain this phenomenon. This review article seeks to outline a novel approach for potentially describing the disparities seen in range of motion research with respect to hypertrophy outcomes by applying the unique length-tension curve of each muscle being examined. As will be discussed in the review, virtually all the results from range of motion studies in various muscles have corresponded to each muscle's length-tension curve; muscles that are active on the descending limb of the curve appear to garner greater hypertrophy from using larger ranges of motion. Conversely, muscles that are not active on the descending limb exhibit similar adaptations despite alterations in range of motion. A novel hypothesis for applying this information to resistance training programs will be presented and discussed.

Assessment of ultrasonography as a diagnostic tool in shoulder pain and alterations in glenohumeral range of motion in tennis players.

IntroductionShoulder pain and alterations in the range of motion are common disorders in tennis players. However, the relation between shoulder structures and these conditions is unknown.AimTo evaluate whether, using ultrasonography, one can identify tennis players with shoulder pain and those having specific changes of the range of rotation of the glenohumeral joint.Material and methodsA total of 66 subjects were assessed through examination of the range of rotation of the glenohumeral joint and ultrasonography.ResultsThe study group consisted of 37 people with shoulder pain (24.2 ±8.6 years) and the control group included 29 subjects without shoulder pain (21.9 ±10.8 years). The prevalence of pathologies of the supraspinatus (SSP), infraspinatus (ISP) or subscapularis (SSC) was significantly higher in the study group than in the control group (p = 0.044) but solely for the combined pathologies. The incidence rate of pathological shoulder changes (the SSP, ISP, SSC and the subacromial bursa) was not correlated with the ranges of rotations or intensity of pain. Glenohumeral internal rotation deficit (GIRD), total rotational motion (TROM) deficit and external rotation deficiency (ERD) were independent of pathological shoulder changes, except the significantly higher prevalence of SSP pathologies among subjects with ERD.ConclusionsUltrasonography could be helpful in identifying tennis players with painful shoulder having rotator cuff pathologies. However, the ability of the method to identify players having specific changes of the range of rotation of the glenohumeral joint is limited, with the exception of tennis players with ERD having SSP pathologies.

Baseline muscle tendon unit stiffness does not affect static stretching of the ankle plantar flexor muscles.

[Purpose] The aim of this study was to investigate the influence of baseline muscle tendon unit stiffness on static stretching. [Participants and Methods] Eighteen healthy males were divided into two groups according to their muscle tendon unit stiffness as follows: High (n=9) and Low (n=9). Flexibility assessment was performed before and after 10 minutes of static stretching. Alterations in range of motion, passive torque at the terminal range of motion, muscle tendon unit stiffness, muscle tendon junction displacement, and tendon length were examined. [Results] No significant interactions were found in all the measurements. After static stretching, the range of motion, passive torque, muscle tendon junction displacement, and tendon length increased, while muscle tendon unit stiffness decreased. There were significant differences in range of motion, muscle tendon unit stiffness, and muscle tendon junction displacement between the groups. [Conclusion] Ten minutes of static stretching increased the range of motion through a decrease in muscle tendon unit stiffness and an increase in tolerance in both groups. Differences in muscle tendon unit stiffness and muscle tendon junction displacement caused the differences in range of motion. Baseline muscle tendon unit stiffness had no effects on static stretching.

Sling-based Exercise for External Rotator Muscles: Effects on Shoulder Profile in Young Recreational Tennis Players

Context: Tennis playing generates specific adaptations, particularly at the dominant shoulder. It remains to be established whether shoulder strength balance can be restored by sling-based training for adolescent recreational tennis players. Objective: We added a sling-based exercise for shoulder external rotators to investigate its effects on external rotator muscle strength, on internal rotator muscle strength, on glenohumeral range of motion and on tennis serve performance. Design: Test-retest design. Setting: Tennis training sports facilities. Participants: Twelve adolescent male players volunteered to participate in this study (age: 13.3 ± 0.5 years; height: 1.64 ± 0.07 cm, mass: 51.7 ± 5.8 kg, International Tennis Number: 8). Intervention: The procedure spanned 10 weeks. For the first five weeks, players performed their regular training (RT) twice a week. For the last five weeks, a sling-based exercise (SE) for strengthening the shoulder external rotator muscles was added to their regular training. Main Outcome Measures: Maximal isometric strength of shoulder external and internal rotator muscles and glenohumeral range of motion in external and internal rotation were assessed in both shoulders. Serve performance was also evaluated by accuracy and post-impact ball velocity, using a radar gun. Results: No change was found in any measurement after the RT period. Significant increases in external (~+5%; p<0.001) and internal (~+2%; p<0.05) rotator muscle strength and in external/internal strength ratio (~+4%; p<0.001) were observed after the SE period. Serve velocity and accuracy were significantly improved after SE (~+2% and ~+24%, respectively; p<0.05 for both), while no clinically meaningful alterations in ranges of motion were observed. Conclusions: Prophylactic intervention through sling-based exercise for strengthening shoulder external rotator muscles appears effective in restoring strength balance at the dominant shoulder, and may prevent adolescent tennis players from sustaining degenerative shoulder problems which could later impair their performance of daily and work-related tasks.

Humeral Torsion as a Risk Factor for Shoulder and Elbow Injury in Professional Baseball Pitchers

Objectives:Participation in baseball causes increased mechanical stress to the throwing arm and has been linked to alterations in shoulder range of motion (ROM) and bony morphology. Range of motion changes, specifically GIRD, has been associated with increased shoulder injury. However, the role of humeral torsion is unclear in shoulder injury. The purpose of this study was to prospectively compare humeral torsion (HT) in professional pitchers who remain healthy as compared with those who go on to suffer shoulder injuries.Methods:We prospectively measured and observed 255 professional pitcher-player seasons prior to 2009-2013 spring training. Bilateral HT was assessed in pitchers who were currently asymptomatic and participating without restriction, in all training, and practices. Humeral torsion was assessed via validated, indirect ultrasonography. Two trials of HT were averaged for data analysis. The side-to-side difference in HT was calculated by subtracting the dominant arm (D) HT from the non-dominant (ND) HT. The pitchers were then followed for the development of shoulder injury over the course of each season. Separate mixed model ANOVAs(side X injury) were used to compare pitchers’ dominant and non-dominant HT between those who suffered shoulder injury to those who did not miss games due to arm injury (α=0.05). Tukey's Post-Hoc tests were used to determine minimum significant differences for significant interaction effects.Results:We observed 30 shoulder injuries. Pitchers with previous elbow injuries(n=30) were excluded from the comparison.(Table 1) Pitchers who suffered a shoulder injury displayed 3.5° less D humeral retrotorsion compared to those pitchers without injury(n=195; P=0.04).(Figure 1).Conclusion:This study showed that pitchers with decreased humeral retrotorsion had a significantly increased risk of shoulder injury. Decreased humeral retrotorsion may hinder the ability of the shoulder to obtain needed ROM, thus increasing stress to the shoulder in late cocking and follow through. Our results should be viewed in context of the relatively small injury numbers but provide preliminary evidence that the influence of HT should be closely examined when considering shoulder injury risk in professional pitchers.

Professional Pitchers With Glenohumeral Internal Rotation Deficit (GIRD) Display Greater Humeral Retrotorsion Than Pitchers Without GIRD

Background: Dominant shoulder glenohumeral internal rotation deficit (GIRD) has been associated with pitching arm injuries. The relationship of humeral torsion on development of GIRD is not clear. Hypothesis: Pitchers displaying GIRD will display greater humeral retrotorsion when compared with those without GIRD. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Humeral torsion and shoulder range of motion (ROM) were measured in 222 professional pitchers before spring training from 2009 to 2012. Shoulder external rotation (ER) and internal rotation (IR) ROM were assessed in 90° of abduction with the scapula stabilized. Humeral torsion was measured via ultrasound using previously described and validated methods. Side-to-side differences in total arc of motion (ER + IR), ER, and IR ROM and humeral torsion were calculated as nondominant minus dominant arm measures for analysis. Pitchers were classified as having GIRD if their dominant arm displayed an IR deficit ≥15° concomitant with a total arc of motion deficit ≥10° compared with their nondominant arm. A mixed-model analysis of variance (side × GIRD) was used to compare dominant and nondominant humeral torsion between pitchers with GIRD (n = 60) and those without GIRD (n = 162). Independent t tests were used to compare the side-to-side difference in humeral torsion between pitchers with GIRD and those without GIRD (α = 0.05). Results: Pitchers with GIRD displayed significantly less humeral torsion (ie, greater retrotorsion) in their dominant arm as compared with those without GIRD (GIRD = 4.5° ± 11.8°, no GIRD = 10.4° ± 11.7°; P = .002). Pitchers with GIRD also displayed a greater side-to-side difference in humeral torsion (GIRD = 19.5° ± 11.9°, no GIRD = 12.3° ± 12.4°; P = .001). However, pitchers with GIRD did not display an increase in dominant ER ROM (dominant ER = 131.8° ± 14.3°, nondominant ER 126.6° ± 13.1°) when compared with those without GIRD (dominant ER = 132.0° ± 14.2°, nondominant ER 122.6° ± 13.1°; P = .03). Pitchers with GIRD displayed expected alterations in ROM (IR = 28.8° ± 9.6°, total arc = 160.6° ± 15.4°; P < .01 for both) when compared with those without GIRD (IR = 39.9° ± 9.9°, total arc = 171.2° ± 15.5°). Conclusion: Pitchers with GIRD displayed greater side-to-side differences and dominant humeral retrotorsion as compared with those without GIRD. The greater humeral retrotorsion may place greater stress on the posterior shoulder resulting in ROM deficits. Pitchers with greater humeral retrotorsion appear to be more susceptible to developing ROM deficits associated with injury and may need increased monitoring and customized treatment programs to mitigate their increased injury risk.

Professional Pitchers with GIRD Display Greater Dominant Humeral Retrotorsion than Pitchers with Normal ROM

Objectives:Glenohumeral internal rotation deficit (GIRD) in the dominant shoulder of a throwing athlete is a previously recognized phenomenon which has been associated with upper extremity injury. The relationship between GIRD and humeral torsion has not clearly been elucidated. The purpose of this study was to compare humeral torsion between professional pitchers presenting with GIRD and those with normal ROM.Methods:Humeral torsion and shoulder range of motion (ROM) was measured in 128 professional pitchers prior to spring training from 2009-2012. Shoulder external (ER) and internal (IR) ROM was assessed in 90º of abduction with the scapula stabilized. Humeral torsion was measured via ultrasound using previously described and validated methods. GIRD was defined as the loss of internal rotation > 15º with a concomitant loss of 10º total arc of motion. The side-to-side difference in HT was calculated by subtracting the dominant arm (D) HT from the non-dominant (ND) HT. A mixed model ANOVA(side X GIRD) were used to compare pitchers dominant and non-dominant HT between pitchers with GIRD to those without GIRD. Independent t-tests were used to compare the side to side difference in HT between pitchers with GIRD and those without (α=0.05).Results:Pitchers with GIRD displayed alterations in ROM (ER=131.8±14.3, IR= 29.1±10.1, Total Arc=160.9±15.5 ) compared with those with normal ROM (ER=132.0±14.2 , IR= 40.5±11.3 , Total Arc= 172.5 ±16.2 ). Pitchers with GIRD displayed significantly less humeral torsion (i.e. greater retro torsion) in their dominant arm compared to those without (GIRD=4.4±12.0º, Normal=10.4±11.6º, P=0.002). Pitchers with GIRD also displayed a greater side to side difference in humeral retro torsion (GIRD=19.5±11.9 compared with 12.4±12.4º, P=0.001). There was no difference in non-dominant humeral torsion in pitchers with and without GIRD (P>0.05).Conclusion:Professional pitchers who display deficits in total arc of motion on the internal rotation side greater than 15º tend to also have greater dominant humeral retro torsion and greater side to side differences. An adaptive increase in humeral retro torsion in the dominant arm due to repetitive throwing may limit internal rotation in the follow through phase of the throwing motion. This, in turn, may increases forces on the posterior soft tissues of the glenohumeral joint leading to the development of GIRD. Given that deficits in total arc of motion and internal rotation are associated with increased arm injury risk future studies should examine the amount of humeral torsion that predisposes a shoulder to develop GIRD.

Posterior Glenohumeral Joint Capsule Contracture

Glenohumeral joint posterior capsule contracture may cause shoulder pain by altering normal joint mechanics. Contracture is commonly noted in throwing athletes but can also be present in nonthrowers. The cause of contracture in throwing athletes is assumed to be a response to the high amount of repetitive tensile force placed on the tissue, whereas the mechanism of contracture in nonthrowers is unknown. It is likely that mechanical and cellular processes interact to increase the stiffness and decrease the compliance of the capsule, although the exact processes that cause a contracture have not been confirmed. Cadaver models have been used to study the effect of posterior capsule contracture on joint mechanics and demonstrate alterations in range of motion and in humeral head kinematics. Imaging has been used to assess posterior capsule contracture, although standard techniques and quantification methods are lacking. Clinically, contracture manifests as a reduction in glenohumeral internal rotation and/or cross body adduction range of motion. Stretching and manual techniques are used to improve range of motion and often decrease symptoms in painful shoulders.

Changes in passive range of motion and development of glenohumeral internal rotation deficit (GIRD) in the professional pitching shoulder between spring training in two consecutive years

Pitching causes increased mechanical stress to the arm and is thought to result in alterations in range of motion (ROM) as a result of osseous and soft tissue adaptations. Understanding the factors that contribute to alterations in ROM will allow for improved understanding of the pitching shoulder. This study examined humeral torsion (HT) and shoulder mobility over 2 consecutive years. Bilateral shoulder mobility and HT were assessed in 33 asymptomatic professional pitchers over 2 spring trainings. A repeated-measures analysis of covariance was used to assess the change in motion of the dominant side/nondominant side across seasons while quantifying pre-existing HT. Prevalence of glenohumeral internal rotation deficit (GIRD) between seasons was compared with χ(2) analysis, and GIRD and non-GIRD pitchers were compared with the independent t test. The dominant shoulder displayed increased external rotation (11.5° ± 0.1°, P = .02) and decreased internal rotation (-8.4° ± 11.0°, P = .03) and horizontal adduction (-17.6° ± 13.8°, P = .01). The nondominant shoulder remained the same. Mean HT was significantly different (P = .001) in the dominant (10° ± 11°) arm than in the nondominant arm (23° ± 11°). A significant number of pitchers had with GIRD (P < .01) at each assessment. ROM was significantly altered between seasons of pitching. These changes likely resulted from soft tissue adaptations because we accounted for humeral retrotorsion. Pitchers who developed GIRD displayed a 7° increase in retrotorsion on the dominant shoulder. Changes in the pitching shoulder over time accounting for humeral retrotorsion may suggest pitching ROM is transient and should be monitored.

Effect of multilevel lumbar disc arthroplasty on the operative- and adjacent-level kinematics and intradiscal pressures: an in vitro human cadaveric assessment

Background context With lumbar arthroplasty gaining popularity, limited data are available highlighting changes in adjacent-level mechanics after multilevel procedures. Purpose Compare operative– and adjacent-segment range of motion (ROM) and intradiscal pressures (IDPs) after two-level arthroplasty versus circumferential arthrodesis. Study design Cadaveric biomechanical study. Methods Ten human cadaveric lumbar spines were used in this investigation. Biomechanical testing was performed according to a hybrid testing protocol using an unconstrained spine simulator under axial rotation (AR), flexion extension (FE), and lateral-bending (LB) loading. Specimens were tested in the following order: 1) Intact, 2) L3–L5 total disc replacement (TDR), 3) L3–L5 anterior interbody cages+pedicle screws. IDP was recorded at proximal and distal adjacent levels and normalized to controls (%intact). Full ROM was monitored at the operative and adjacent levels and reported in degrees. Results Kinematics assessment revealed L3–L5 ROM reduction after both reconstructions versus intact controls (p<.05). However, global quality of segmental motion distributed over L2–S1 was preserved in the arthroplasty group but was significantly altered after circumferential fixation. Furthermore, adjacent-level ROM was increased for the arthrodesis group under LB at both segments and during AR at L2–L3 relative to controls (p<.05). FE did not reveal any intergroup statistical differences. Nonetheless, after arthrodesis IDPs were increased proximally under all three loading modalities, whereas distally a significant IDP rise was noted during AR and LB (p<.05). No statistical differences in either biomechanical parameter were recorded at the adjacent levels between intact control and TDR groups. Conclusions Our results indicate no significant adjacent-level biomechanical changes between arthroplasty and control groups. In contrast, significant alterations in ROM and IDP were recorded both proximally (ROM=LB & AR; IDP=AR, FE, LB) and distally (ROM=LB; IDP=AR & LB) after circumferential arthrodesis. Therefore, two-level lumbar arthroplasty maintains a more favorable biomechanical environment at the adjacent segments compared with the conventional transpedicular fixation technique. This, in turn, may have a positive effect on the rate of the transition syndrome postoperatively.