Biomedical subjects

H E J Veeger

Publications and source records attributed to H E J Veeger.

At least 19 recordsLinked to original sources

PubMed2007

Shoulder function: the perfect compromise between mobility and stability.

Shoulder function is a compromise between mobility and stability. Its large mobility is based on the structure of the glenohumeral joint and simultaneous motion of all segments of the shoulder girdle. This requires fine-tuned muscle coordination. Given the joint's mobility, stability is mainly based on active muscle control with only a minor role for the glenohumeral capsule, labrum and ligaments. In this review factors influencing stability and mobility and their consequences for strength are discussed, with special attention to the effects of morphology, muscle function and sensory information.

Acromioclavicular Joint↗

PubMed2006

Morphological muscle and joint parameters for musculoskeletal modelling of the lower extremity.

BACKGROUND: To assist in the treatment of gait disorders, an inverse and forward 3D musculoskeletal model of the lower extremity will be useful that allows to evaluate if-then scenarios. Currently available anatomical datasets do not comprise sufficiently accurate and complete information to construct such a model. The aim of this paper is to present a complete and consistent anatomical dataset, containing the orientations of joints (hip, knee, ankle and subtalar joints), muscle parameters (optimum length, physiological cross sectional area), and geometrical parameters (attachment sites, 'via' points). METHODS: One lower extremity, taken from a male embalmed specimen, was studied. Position and geometry were measured with a 3D-digitizer. Optotrak was used for measurement of rotation axes of joints. Sarcomere length was measured by laser diffraction. FINDINGS: A total of 38 muscles were measured. Each muscle was divided in different muscle lines of action based on muscle morphology. 14 Ligaments of the hip, knee and ankle were included. INTERPRETATION: The presented anatomical dataset embraces all necessary data for state of the art musculoskeletal modelling of the lower extremity. Implementation of these data into an (existing) model is likely to significantly improve the estimation of muscle forces and will thus make the use of the model as a clinical tool more feasible.

Aged↗

PubMed2006

Movement patterns of the upper extremity and trunk associated with impaired forearm rotation in patients with hemiplegic cerebral palsy compared to healthy controls.

The aim of this study was to objectively assess the relationship between impaired forearm rotation and movement patterns of the upper arm and trunk in patients with hemiplegic cerebral palsy. For this purpose, 'extrinsic forearm rotation' was introduced as a parameter to quantify the cumulative result of all movements that supplement forearm rotation. The results of three-dimensional video analysis of the upper extremity and trunk in different reaching tasks in eight male and two female patients (mean age, 16 years and 2 months) were compared to those of 10 case-matched controls. The active forearm rotation impairment in the patient group as compared to the controls was combined with a significantly higher value for 'extrinsic forearm rotation'. In this way, we objectively measured compensatory movement patterns associated with impaired forearm rotation and, consequently, we advocate assessment of the overall movement strategy rather than just the forearm deformity in patients with hemiplegic cerebral palsy.

Abdomen↗

PubMed2006

The relationship between two different mechanical cost functions and muscle oxygen consumption.

Inverse-dynamic models often use cost functions to solve the load-sharing problem. Although it is often assumed that energy is minimised, most cost functions are based on mechanically related measures like muscle force or stress. The aim of this study was to analyse the relationships of two cost functions with experimentally determined data on muscle energy consumption. Four subjects performed isometric contractions generating combinations of elbow flexion/extension and pro/supination moments. Muscle oxygen consumption (VO2) of the m. biceps breve, m. biceps longum, m. brachioradialis and m. triceps laterale was measured with near infrared spectroscopy. Both cost functions were implemented into an existing inverse-dynamic shoulder and elbow model and the individual cost values per muscle were calculated, normalised and subsequently compared to experimental VO2 values. The minimum stress cost function led to a good correspondence between VO2 and cost for the m. triceps laterale but for the flexor muscles cost was significantly lower. A newly proposed energy-related cost function showed, however, a far better correspondence. The inclusion of a linear term and muscle mass in the new criterion led model results to correspond better to experimental results. The energy-related cost function appeared to be a better measure for muscle energy consumption than the stress cost function and led to more realistic predictions of muscle activation.

Adult↗

PubMed2006

Pathological muscle activation patterns in patients with massive rotator cuff tears, with and without subacromial anaesthetics.

A mechanical deficit due to a massive rotator cuff tear is generally concurrent to a pain-induced decrease of maximum arm elevation and peak elevation torque. The purpose of this study was to measure shoulder muscle coordination in patients with massive cuff tears, including the effect of subacromial pain suppression. Ten patients, with MRI-proven cuff tears, performed an isometric force task in which they were asked to exert a force in 24 equidistant intervals in a plane perpendicular to the humerus. By means of bi-polar surface electromyography (EMG) the direction of the maximal muscle activation or principal action of six muscles, as well as the external force, were identified prior to, and after subacromial pain suppression. Subacromial lidocaine injection led to a significant reduction of pain and a significant increase in exerted arm force. Prior to the pain suppression, we observed an activation pattern of the arm adductors (pectoralis major pars clavicularis and/or latissimus dorsi and/or teres major) during abduction force delivery in eight patients. In these eight patients, adductor activation was different from the normal adductor activation pattern. Five out of these eight restored this aberrant activity (partly) in one or more adductor muscles after subacromial lidocaine injection. Absence of glenoid directed forces of the supraspinate muscle and compensation for the lost supraspinate abduction torque by the deltoideus leads to destabilizating forces in the glenohumeral joint, with subsequent upward translation of the humeral head and pain. In order to reduce the superior translation force, arm adductors will be co-activated at the cost of arm force and abduction torque. Pain seems to be the key factor in this (avoidance) mechanism, explaining the observed limitations in arm force and limitations in maximum arm elevation in patients suffering subacromial pathologies. Masking this pain may further deteriorate the subacromial tissues as a result of proximal migration of the humeral head and subsequent impingement of subacromial tissues.

Aged↗

PubMed2006

Movement patterns of the upper extremity and trunk before and after corrective surgery of impaired forearm rotation in patients with cerebral palsy.

The effect of surgical correction of impaired forearm rotation on associated body movement patterns was studied prospectively by comparison of preoperative and postoperative three-dimensional video analysis of the upper extremity and trunk in eight male and two female patients with hemiplegic cerebral palsy (CP; mean age 16y 2mo [SD 4y 11mo]; range 11-27y). A customized parameter, 'extrinsic forearm rotation', was used to quantify associated movements supplementing forearm rotation. After surgical correction of the pronation deformity, active forearm supination during a functional reaching task had improved by a mean of 37 degrees in combination with significantly decreased extrinsic forearm rotation by a mean of 13 degrees . In addition, an average loss of 16 degrees of active pronation in combination with increased extrinsic forearm rotation (mean 8 degrees ) was observed. On the basis of these results we conclude that successful surgical correction of a pronation deformity in patients with CP directly affects related movement patterns of the upper extremity and trunk.

Adolescent↗

PubMed2006

Upper extremity musculoskeletal pain during and after rehabilitation in wheelchair-using persons with a spinal cord injury.

STUDY DESIGN: Prospective cohort study. OBJECTIVES: To study upper extremity musculoskeletal pain during and after rehabilitation in wheelchair-using subjects with a spinal cord injury (SCI) and its relation with lesion characteristics, muscle strength and functional outcome. SETTING: Eight rehabilitation centers with an SCI unit in the Netherlands. METHODS: Using a questionnaire, number, frequency and seriousness of musculoskeletal pain complaints of the upper extremity were measured. A pain score for the wrist, elbow and shoulder joints was calculated by multiplying the seriousness by the frequency of pain complaints. An overall score was obtained by adding the scores of the three joints of both upper extremities. Muscle strength was determined by manual muscle testing. The motor score of the functional independence measure provided a functional outcome. All outcomes were obtained at four test occasions during and 1 year after rehabilitation. RESULTS: Upper extremity pain and shoulder pain decreased over time (30%) during the latter part of in-patient rehabilitation (P<0.001). Subjects with tetraplegia (TP) showed more musculoskeletal pain than subjects with paraplegia (PP) (P<0.001). Upper extremity pain and shoulder pain were significantly inversely related to functional outcome (P<0.001). Muscle strength was significantly inversely related to shoulder pain (P<0.001). Musculoskeletal pain at the beginning of rehabilitation and BMI were strong predictors for pain 1 year after in-patient rehabilitation (P<0.001). CONCLUSIONS: Subjects with TP are at a higher risk for upper extremity musculoskeletal pain and for shoulder pain than subjects with PP. Higher muscle strength and higher functional outcome are related to fewer upper extremity complaints.

Adolescent↗

PubMed2005

Glenohumeral joint loading in tetraplegia during weight relief lifting: a simulation study.

BACKGROUND: The incidence of shoulder complaints in wheelchair users is high and the etiology is poorly understood. The goal of this study was to examine the effect of lesion level and isolated triceps muscle paresis on the internal load on the shoulder by simulation. METHODS: Kinematic and kinetic profiles from four able-bodied subjects and four subjects with tetraplegia were used as input for an inverse dynamics biomechanical model. The model was modified to simulate lesion level and triceps muscle paresis. FINDINGS: The simulations resulted in a significantly higher (+56%) glenohumeral contact force (P=0.037) for tetraplegic profiles than for able-bodied profiles. The model modifications to simulate lesion level only had a minor effect (+7%) on the calculated glenohumeral contact force. More simulations were successful at lower triceps force levels for tetraplegic profiles compared to able-bodied profiles (P=0.012). The muscle forces at the simulated T1 lesion were not significantly higher in tetraplegic profiles compared to able-bodied profiles. INTERPRETATION: The glenohumeral contact force for the tetraplegic profiles is mainly higher due to different task performance. Model modifications only have a minor effect on the calculated glenohumeral contact force. For able-bodied profiles the triceps force seems to be an important factor. The high internal load at the shoulder recommends new techniques of weight relief lifting and proper training of the arm-shoulder muscles in rehabilitation.

Arm↗

PubMed2005

A kinematical analysis of the shoulder after arthroplasty during a hair combing task.

BACKGROUND: After shoulder arthroplasty, post-operative Range of Motion is usually compromised. It is, however, unclear to what extent limitations in Range of Motion are related to functional outcome in terms of Activities of Daily Living. METHODS: The upper extremity motions of 13 patients (16 shoulders) and a control group (N = 24) during four Range of Motion tasks and Activities of Daily Living were measured using a six degree-of-freedom electromagnetic tracking device. Based on the results for the Activities of Daily Living task 'hair combing', the patient groups was divided into a group that could perform this task ('Able', N = 8, 10 shoulders) and a group that could not perform the task ('Unable', N = 6, six shoulders). RESULTS: Both patient groups showed considerable limitation in glenohumeral Range of Motion, when compared to controls, but between patient groups only axial rotation Range of Motion was different: the 'Able' group has a larger external rotational Range of Motion, but less internal rotation. During 'combing hair' the Able group appeared to successfully perform the task through a larger clavicular retraction. INTERPRETATION: The ability to perform, or not perform a task appeared to be related to a compensatory movement implementation by means of clavicular retraction. It is concluded that the functional outcome after arthroplasty is limited due to a lack of glenohumeral Range of Motion but that it is possible to compensate for this restriction.

Activities of Daily Living↗

PubMed2005

Requirements for upper extremity motions during activities of daily living.

BACKGROUND: Functioning of the upper extremity after implantation of an endoprosthesis remains limited despite the achieved pain relief. Upper extremity kinematics can give insight into function after shoulder arthroplasty. Data on ranges of motion related to the performance of a selection of activities of daily living can aid the clinician in evaluating the outcome of the shoulder and elbow arthroplasties. METHODS: Cross-sectional descriptive study of range of motion and activities of daily living kinematics, conducted on non-impaired subjects. The shoulder and elbow motions of 24 healthy female subjects are measured with an electromagnetic tracking device while performing 8 range of motion tasks and five activities of daily living. The angles of shoulder and elbow are calculated during these tasks. RESULTS: A data set with upper extremity joint angles has been obtained. Large glenohumeral rotations are found for the tasks that require high elevation angles. Large axial rotations of the humerus are found for two of the activities of daily living tasks: the perineal care task and the hair-combing task. Large elbow flexions were seen in the following tasks: combing hair, washing the axilla and eating with a spoon. INTERPRETATION: This study shows a suitable method to describe range of motion and activities of daily living and can serve as a starting point for developing a database on how activities of daily living are performed in a larger population and which joint angles are required to perform these tasks. Results can be used to identify restrictions in upper extremity functioning in patients with shoulder impairments.

Activities of Daily Living↗

PubMed2005

Influence of task complexity on mechanical efficiency and propulsion technique during learning of hand rim wheelchair propulsion.

OBJECTIVE: To investigate the consequence of task complexity on gross mechanical efficiency and propulsion technique during the learning process of hand rim wheelchair propulsion. METHODS: Three groups of unimpaired subjects (N=10 each) received a 3-week wheelchair practice period (3 week(-1), nine practice trials) with different levels of complexity, i.e. propelling a stationary wheelchair ergometer, wheelchair propulsion on a motor-driven treadmill or at a circular wheelchair track. During practice trials 1 and 9, gross mechanical efficiency and propulsion technique variables (work per cycle, cycle frequency, push and cycle time, effective force) were measured. RESULTS: Using multi-level regression analysis, no differences in the development over time in mechanical efficiency and propulsion technique could be discerned between the three conditions of task complexity. Only the percentage push time during the cycle decreased significantly more in the group that practiced on the ergometer compared to the treadmill-practice group. For all three groups a change over time was shown for cycle frequency, push time and cycle time. DISCUSSION: Under the current experimental conditions, task complexity does not have an influence on gross mechanical efficiency and propulsion technique during the learning process of wheelchair propulsion. The 3-week practice period had a favorable practice effect on timing regardless of the task complexity.

Adaptation, Physiological↗

PubMed2004

Effectiveness of tendon transfers for massive rotator cuff tears: a simulation study.

UNLABELLED: OBJECTIVE To determine what the most effective tendon transfer is in the case of a dysfunctional rotator cuff. DESIGN: A tendon transfer procedure of latissimus dorsi, teres major or a combination of these two to the insertions of either teres minor, infraspinatus, supraspinatus, or subscapularis is simulated using a biomechanical musculoskeletal model of the upper extremity. BACKGROUND: Massive rotator cuff tears are not easily repaired. To compensate for this loss of rotator cuff function other techniques like muscle transfers are developed. METHODS: Three range of motion tasks and six activities of daily living of 24 subjects were measured. Kinematics from these tasks were used as input to the Delft Shoulder and Elbow Model. The muscle parameters of the Delft Shoulder and Elbow Model were modified to simulate a rotator cuff tear and the ability to perform the measured tasks with and without simulated transfer procedures was checked. RESULTS: The highest improvements (28-30%, P = 0.00 ) in the ability to perform tasks were observed after a simulated tendon transfer of either both muscles or teres major alone attached to the supraspinatus or infraspinatus insertion. Although all transfer procedures produce significant improvements (P = 0.00 ), there is a significant difference between the procedures (Chi square=58.8, P = 0.00 ) dependent on attachment site. CONCLUSIONS: According to the simulation procedure used in the current study, a tendon transfer of teres major and latissimus dorsi or teres major alone to the supraspinatus insertion appears to be the most effective procedure in the case of a dysfunctional rotator cuff. Practical factors, like subacromial space, volume of the muscles and tendons, tensile properties and the ability to split the muscles, will finally determine which is the preferred transfer option.

Analysis of Variance↗

PubMed2004

Biomechanical analysis of tendon transfers for massive rotator cuff tears.

OBJECTIVE: To determine why certain tendon transfers are mechanically more effective than other tendon transfers for the treatment of a massive rotator cuff tear. DESIGN: A tendon transfer procedure of latissimus dorsi, teres major or a combination of these two to the insertions of either teres minor, infraspinatus, supraspinatus, or subscapularis is simulated using a biomechanical musculoskeletal model of the upper extremity. BACKGROUND: Massive rotator cuff tears are not easily repaired. To compensate for the loss of rotator cuff function, techniques such as muscle transfers are developed. METHODS: Three range of motion tasks were used as input to the Delft shoulder and elbow model. The muscle parameters of the Delft shoulder and elbow model were modified to simulate a rotator cuff tear. A biomechanical analysis of the transferred muscles was performed, taking outcome variables such as moment arms, muscle length and muscle force into account. RESULTS: Due to the massive rotator cuff tear, an elevation and external rotation moment is lost. When the tendon was transferred to the insertions of infraspinatus or supraspinatus, the humerus was capable of elevating and externally rotating. CONCLUSIONS: On the basis of mechanical parameters such as moment arms, muscle length and force it can be concluded that a tendon transfer of the teres major to the supraspinatus insertion will produce the best functional outcome in the treatment of massive rotator cuff tears. RELEVANCE: To find biomechanical evidence for an optimal tendon transfer that will lead to improved treatment of patients with a massive rotator cuff tear.

Biomechanical Phenomena↗

PubMed2004

Mechanical evaluation of the Pronator Teres rerouting tendon transfer.

We simulated pronator teres rerouting using a three-dimensional biomechanical model of the arm. Simulations comprised the evaluation of changes in muscle length and the moment arm of pronator teres with changes in forearm axial rotation and elbow flexion. The rerouting of Pronator Teres was simulated by defining a path for it through the interosseous membrane with re-attachment to its original insertion. However the effect of moving the insertion to new positions, 2 cm below and above, the original position was also assessed. The effect on total internal rotation and external rotation capacity was determined by calculating the potential moments for pronator teres, supinator, pronator quadratus, biceps brachii and brachioradialis. Pronator teres was found to be a weak internal rotator in extreme pronation, but a strong internal rotator in neutral rotation and in supination. After rerouting pronator teres was only a strong external rotator in full pronation and not at other forearm positions, where the effect of rerouting was comparable to a release procedure.

Biomechanical Phenomena↗

PubMed2004

Three-dimensional video analysis of forearm rotation before and after combined pronator teres rerouting and flexor carpi ulnaris tendon transfer surgery in patients with cerebral palsy.

The effect of combined pronator teres rerouting and flexor carpi ulnaris transfer on forearm rotation was prospectively studied by comparison of pre- and postoperative three-dimensional analysis of forearm range of motion in ten patients with cerebral palsy. One year postoperatively, surgery had improved maximal supination of the forearm in all patients by an average of 63 degrees, but there was also a mean loss of 40 degrees pronation. Forearm range of motion increased by a mean of 23 degrees. The centre of the range of motion on average shifted 52 degrees in the direction of supination. Based on these results of objective forearm range of motion analysis, we conclude that the common combination of pronator teres rerouting and flexor carpi ulnaris transfer in patients with cerebral palsy effectively facilitates active supination but impairs active pronation.

Adolescent↗

PubMed2004

Effect of wheelchair stroke pattern on mechanical efficiency.

OBJECTIVE: To investigate the effect of different wheelchair stroke patterns on efficiency and propulsion technique (force application and timing). DESIGN: Inexperienced, able-bodied subjects were randomly divided into two velocity groups (1.11 m/sec [n = 13] and 1.39 m/sec [n = 11]). An external (medium) load was set at 0.23 N/kg. Subjects performed four 4-min exercise blocks on a wheelchair ergometer. The first block was performed with a freely chosen movement pattern of the hand. Thereafter, the pumping, semicircular, or single-looping over propulsion pattern were performed in a counterbalanced order. Gross mechanical efficiency and propulsion technique variables were measured with Oxycon Alpha and an instrumented wheelchair ergometer. RESULTS: A significant difference was found for mechanical efficiency, with pumping showing the highest efficiency and semicircular the lowest efficiency, regardless of velocity. Timing variables and negative power deflections before and after the push phase showed significant differences between the stroke patterns. CONCLUSIONS: Pumping is the energetically most efficient stroke pattern in contrast to the semicircular pattern in this subject group. Propulsion technique could not explain the difference in efficiency.

Adult↗

PubMed2003

The push force pattern in manual wheelchair propulsion as a balance between cost and effect.

We investigate the hypothesis that the direction of the propulsion force in manual wheelchair propulsion can be interpreted as a result of the balance between the mechanical task requirements and the driver's biomechanical possibilities. We quantify the balance at the joint level in the form of an effect-cost criterion, from which we predict the force direction that results in an optimal compromise. Kinematic and dynamic data were collected from nine habitual wheelchair users driving at four velocities (0.83, 1.11, 1.39, 1.67 m/s) and three external power levels (10, 20, 30 W). Experimental data and predictions are in good agreement in the middle and final part of the push; the effect-cost value in this region approximates the achievable maximum. Early in the push the effect-cost criterion predicts an upwards propulsion force whereas the experimental force is downwards, the difference probably being mainly attributable to the force generation dynamics of the muscles. As a result of the geometric features of large-rim manual wheelchairs, the mechanically required and biomechanically preferred force directions are not in accordance during a substantial part of the push, making even the best compromise a poor one. This may contribute to the low mechanical efficiency of manual wheelchair propulsion and the high incidence of shoulder complaints.

Adult↗

PubMed2003

Muscle oxygen consumption, determined by NIRS, in relation to external force and EMG.

Local oxygen consumption in a muscle (VO(2)) can be determined by near infrared spectroscopy (NIRS). In principle it should be possible to use this measure to validate musculoskeletal models. However, the relationship between VO(2) and external force, or between VO(2) and surface EMG, as a measure for muscle activity, is hardly known. The aim of this study was: (1) to evaluate the characteristics of the relationship between VO(2) and external moments and (2) to determine whether differences exist between the EMG-moment relationship and the VO(2)-moment relationship. Subjects (n=5) were asked to perform isometric contractions exerting combinations of elbow flexion and pro/supination moments at force levels up to 70% of their maximum. Simultaneous surface-EMG and NIRS measurements were performed on the m. biceps breve (BB) and the m. brachioradialis (BR). A linear relationship was found between EMG and VO(2). For the BB VO(2) and EMG were linearly related to both the flexion moment and the pro/supination moment. However, for the BR only a linear relationship with flexion moment was found. As expected, based on the findings above, the relationship between VO(2) and elbow flexion moment can be described by a linear equation, under the conditions of this study (isometric, and force levels up to 70%). These findings suggest that load sharing is independent of force level and that next to EMG, VO(2) can be used for the validation of musculoskeletal models.

Adult↗