determining-controlling-external-power-output-during-regular-handrim

Determining and Controlling External Power Output During Regular Handrim Wheelchair Propulsion

The use of a manual wheelchair is critical to 1% of the world&#39;s population. Human powered wheeled mobility research has considerably matured, which ...

VU University

Delft University of Technology, Delft

Positions of the shoulder joint are commonly described in terms of degrees of humeral elevation in the principal planes. This approach is inadequate for an accurate and unambiguous description of functional arm movements that are not confined to these planes. In this paper, a general unambiguous method for describing shoulder positions is adopted and visualized in globe graphs. This facilitates the use and interpretation of the method in clinical practice. To illustrate this globe system of description, a healthy subject participated in the experiments. The shoulder position is described for several functional and standardized tasks for the upper limb with three angles: (1) the angle of the plane of elevation, (2) the angle of elevation within the plane of elevation, and (3) the angle of axial rotation. With these parameters, the position of the upper arm can be visualized as a position on a "globe" about the shoulderjoint. Although not perfect, the globe system provides the most unambiguous description of functional thoraco-humeral positions, which is easy to apply in clinical practice.

The globe system: an unambiguous description of shoulder positions in daily life movements.

Laxity may be a trigger for chronic unidentified wrist pain. To determine whether this is the case, first an objective method to quantify wrist laxity needs to be defined. This study investigates different quantification methods (reference tests) from the literature and compares these with the judgment of 2 independent experienced clinicians (index test, or gold standard).

Quantification of wrist joint laxity.

To investigate whether passive and active reproduction of joint position, as well as detection of passive motion (as measures of a subject's proprioception) of the shoulder differ while sitting compared with lying supine.

Effect of body orientation on proprioception during active and passive motions.

To aid understanding of the working of the upper extremity, several musculoskeletal models of the shoulder and arm have been developed. These models comprise the full shoulder girdle, which implies that the thoracohumeral link is formed by a scapular and clavicular segment. These models are based upon limited anatomical parameter sets and work on the assumption of a general control principle. Upper Extremity models have proven to be useful for different categories of applications, such as quantification of the load on musculoskeletal structures, or the evaluation of changes in the musculoskeletal structure on function and mechanical integrity ("what if" questions). Although these models are increasingly used, validation has long been a difficult issue. With the development of instrumented endoprostheses, a new method for model validation has come within reach. Up till now results have indicated that to obtain 'true' force values, models should be scaled, and should allow for cocontraction. Musculoskeletal models will be finding their way in education and in clinical decision making. On the longer run individualized models might become important for application to individual patients, although scaling will for some time remain a difficult issue.

"What if": the use of biomechanical models for understanding and treating upper extremity musculoskeletal disorders.

To evaluate whether outcomes based on stopwatch time and power output (PO) over a 15m-overground wheelchair sprint test can be used to assess wheelchair-specific anaerobic work capacity, by studying their relationship with outcomes on a Wingate-based 30s-wheelchair ergometer sprint (WAnT).

Can a 15m-overground wheelchair sprint be used to assess wheelchair-specific anaerobic work capacity?

Range of motion after total shoulder arthroplasty is better than after reverse shoulder arthroplasty, however with similar clinical outcome. It is unclear if this difference can only be found in the different range of motion or also in the force generating capacity.

Isokinetic strength differences between patients with primary reverse and total shoulder prostheses: muscle strength quantified with a dynamometer.

The objective of this study was to investigate the effects of a low-intensity wheelchair training on propulsion technique in inactive people with long-term spinal cord injury.

Low-Intensity Wheelchair Training in Inactive People with Long-Term Spinal Cord Injury: A Randomized Controlled Trial on Propulsion Technique.

To propel in an energy-efficient manner, handrim wheelchair users must learn to control the bimanually applied forces onto the rims, preserving both speed and direction of locomotion. Previous studies have found an increase in mechanical efficiency due to motor learning associated with changes in propulsion technique, but it is unclear in what way the propulsion technique impacts the load on the shoulder complex. The purpose of this study was to evaluate mechanical efficiency, propulsion technique and load on the shoulder complex during the initial stage of motor learning.

Early motor learning changes in upper-limb dynamics and shoulder complex loading during handrim wheelchair propulsion.

Improved understanding of mobility performance in wheelchair basketball is required to increase game performance. The aim of this study was to quantify the wheelchair-athlete activities of players in different field positions and of different playing standard during wheelchair basketball matches. From video analysis, absolute and relative duration and frequency of wheelchair movements and athlete control options were examined in 27 national standard and 29 international standard players during entire wheelchair basketball matches. Between-group factorial analysis of variances identified that national players drove more forward (42.6 ± 6.8 vs. 35.4 ± 3.7%; effect size Cohen's d (ES) = 1.48) and started more often driving forward (33.9 ± 2.6 vs. 31.8 ± 2.8; ES = 0.77) during a match while the mean activity duration for a single driving forward activity was longer (4.3 ± 0.9 vs. 3.7 ± 0.6 s; ES = 0.75) than for international players. Furthermore, national players performed fewer rotational movements (21.8 ± 4.0 vs. 28.9 ± 7.8%; ES = -1.30) and started less often with the rotational movements (35.0 ± 3.6 vs. 40.5 ± 5.5; ES = -1.21) while the mean activity duration for a single rotation activity was shorter (2.1 ± 0.3 vs. 2.3 ± 0.3 s; ES = -0.67) than for international players. Differences in mobility performance among guard, forward and centre players were minimal. The results should help wheelchair basketball coaches specify wheelchair-handling training techniques and means to optimise wheelchair-athlete configurations. 

Do field position and playing standard influence athlete performance in wheelchair basketball?

The variability in the numerous tasks in which we use our hands is very large. However, independent movement control of individual fingers is limited. To assess the extent of finger independency during full-range finger flexion including all finger joints, we studied enslaving (movement in non-instructed fingers) and range of independent finger movement through the whole finger flexion trajectory in single and multi-finger movement tasks. Thirteen young healthy subjects performed single- and multi-finger movement tasks under two conditions: active flexion through the full range of movement with all fingers free to move and active flexion while the non-instructed finger(s) were restrained. Finger kinematics were measured using inertial sensors (PowerGlove), to assess enslaving and range of independent finger movement. Although all fingers showed enslaving movement to some extent, highest enslaving was found in adjacent fingers. Enslaving effects in ring and little finger were increased with movement of additional, non-adjacent fingers. The middle finger was the only finger affected by restriction in movement of non-instructed fingers. Each finger showed a range of independent movement before the non-instructed fingers started to move, which was largest for the index finger. The start of enslaving was asymmetrical for adjacent fingers. Little finger enslaving movement was affected by multi-finger movement. We conclude that no finger can move independently through the full range of finger flexion, although some degree of full independence is present for smaller movements. This range of independent movement is asymmetric and variable between fingers and between subjects. The presented results provide insight into the role of finger independency for different types of tasks and populations.

Variable and Asymmetric Range of Enslaving: Fingers Can Act Independently over Small Range of Flexion.

The fingers of the human hand cannot be controlled fully independently. This phenomenon may have a neurological as well as a mechanical basis. Despite previous studies, the neuromechanics of finger movements are not fully understood. The aims of this study were (1) to assess the activation and coactivation patterns of finger specific flexor and extensor muscle regions during instructed single finger flexion and (2) to determine the relationship between enslaved finger movements and respective finger muscle activation. In 9 healthy subjects (age 22-29), muscle activation was assessed during single finger flexion using a 90 surface electromyography electrode grid placed over the flexor digitorum superficialis (FDS) and the extensor digitorum (ED). We found (1) no significant differences in muscle activation timing between fingers, (2) considerable muscle activity in flexor and extensor regions associated with the non-instructed fingers and (3) no correlation between the muscle activations and corresponding movement of non-instructed fingers. A clear disparity was found between the movement pattern of the non-instructed fingers and the activity pattern of the corresponding muscle regions. This suggests that mechanical factors, such as intertendinous and myofascial connections, may also affect finger movement independency and need to be taken into consideration when studying finger movement.

Activity patterns of extrinsic finger flexors and extensors during movements of instructed and non-instructed fingers.

Altered scapular kinematics have been associated with shoulder pain and functional limitations. To understand kinematics in persons with spinal cord injury during manual handrim wheelchair propulsion, a description of normal scapular behaviour in able-bodied persons during this specific task is a prerequisite for accurate interpretation. The primary aim of this study is to describe scapular kinematics in able-bodied persons during manual wheelchair propulsion.

Scapular kinematics during manual wheelchair propulsion in able-bodied participants.

The purpose of this study was to determine whether stride length and knee angle of the leading leg at foot contact, at the instant of maximal external rotation of the shoulder, and at ball release are associated with ball speed in elite youth baseball pitchers. In this study, fifty-two elite youth baseball pitchers (mean age 15.2 SD (standard deviation) 1.7 years) pitched ten fastballs. Data were collected with three high-speed video cameras at a frequency of 240 Hz. Stride length and knee angle of the leading leg were calculated at foot contact, maximal external rotation, and ball release. The associations between these kinematic variables and ball speed were separately determined using generalized estimating equations. Stride length as percentage of body height and knee angle at foot contact were not significantly associated with ball speed. However, knee angles at maximal external rotation and ball release were significantly associated with ball speed. Ball speed increased by 0.45 m/s (1 mph) with an increase in knee extension of 18 degrees at maximal external rotation and 19.5 degrees at ball release. In conclusion, more knee extension of the leading leg at maximal external rotation and ball release is associated with higher ball speeds in elite youth baseball pitchers.

Article	Year
The globe system: an unambiguous description of shoulder positions in daily life movements. Journal of rehabilitation research and development\| PubMed ID: 15077640	2003
Quantification of wrist joint laxity. The Journal of hand surgery\| PubMed ID: 18590849	2008
Effect of body orientation on proprioception during active and passive motions. American journal of physical medicine & rehabilitation\| PubMed ID: 19935182	2009
"What if": the use of biomechanical models for understanding and treating upper extremity musculoskeletal disorders. Manual therapy\| PubMed ID: 20951628	2011
Can a 15m-overground wheelchair sprint be used to assess wheelchair-specific anaerobic work capacity? Medical engineering & physics\| PubMed ID: 24529650	2014
Isokinetic strength differences between patients with primary reverse and total shoulder prostheses: muscle strength quantified with a dynamometer. Clinical biomechanics (Bristol, Avon)\| PubMed ID: 25248943	2014
Low-Intensity Wheelchair Training in Inactive People with Long-Term Spinal Cord Injury: A Randomized Controlled Trial on Propulsion Technique. American journal of physical medicine & rehabilitation\| PubMed ID: 25802961	2015
Early motor learning changes in upper-limb dynamics and shoulder complex loading during handrim wheelchair propulsion. Journal of neuroengineering and rehabilitation\| PubMed ID: 25889389	2015
Do field position and playing standard influence athlete performance in wheelchair basketball? Journal of sports sciences\| PubMed ID: 26222201	2016
Variable and Asymmetric Range of Enslaving: Fingers Can Act Independently over Small Range of Flexion. PloS one\| PubMed ID: 27992598	2016
Activity patterns of extrinsic finger flexors and extensors during movements of instructed and non-instructed fingers. Journal of electromyography and kinesiology : official journal of the International Society of Electrophysiological Kinesiology\| PubMed ID: 28279574	2018
Scapular kinematics during manual wheelchair propulsion in able-bodied participants. Clinical biomechanics (Bristol, Avon)\| PubMed ID: 29554550	2018
Knee Angle and Stride Length in Association with Ball Speed in Youth Baseball Pitchers. Sports (Basel, Switzerland)\| PubMed ID: 29910355	2018

DirkJan H. E. J. Veeger

Biography

JoVE Journal Publications

Other Publications