Thomas W . J . Janssen

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Manual wheelchair propulsion in daily life and sports is increasingly being studied. Initially, an engineering and physiological perspective was taken. More recently a concomitant biomechanics interest is seen. Themes of biomechanical and physiological studies today are performance enhancing aspects of wheelchair use and the ergonomics of wheelchair design.(More)
The objective of this study was to assess the nature of muscle weakness in both legs after stroke compared with able-bodied control individuals and to examine whether there is a relationship between the degree of muscle weakness and coactivation of knee extensors and flexors as well as voluntary activation capacity of knee extensors of both paretic and(More)
OBJECTIVE To determine the net moments on the glenohumeral joint and elbow joint during wheelchair activities. DESIGN Kinematics and external forces were measured during wheelchair activities of daily living (level propulsion, riding on a slope, weight-relief lifting, reaching, negotiating a curb) and processed in an inverse dynamics biomechanic model. (More)
The purpose of this study was to determine physical capacity, gross efficiency (GE), and physical strain (PS) of 16 male handcycle users during a 10K race, and to relate these to race performance. All subjects used a handcycle system attached to their own wheelchair and were classified into a group with (A1/A2; N=10) and without (A3; N=6) upper-limb(More)
OBJECTIVE Post-stroke shoulder pain is a common phenomenon in hemiplegia and impedes rehabilitation. The aim of this study was to identify a possible relationship between post-stroke shoulder pain, scapula resting position and shoulder motion. METHODS Shoulder kinematics of 27 patients after stroke (17 men) were compared with 10 healthy age-matched(More)
OBJECTIVE There is increasing evidence that robot-assisted treadmill training might be useful for gait rehabilitation after stroke. The aim of this study was to evaluate the muscle activity of stroke patients during robot-assisted walking and overground walking, and of a group of able-bodied subjects during overground walking. DESIGN Case-control(More)
*Albrecht-von-Haller Institute of Plant Sciences, Georg-August-Universität Göttingen, Untere Karspüle 2, 37073 Göttingen, Germany; yMuseum National d’Histoire Naturelle, Départment de Systématique et Evolution, 16 Rue Buffon, 75005 Paris, France; zNational Herbarium of the Netherlands, Leiden University Branch, P.O. Box 9514, 2300 RA Leiden, The(More)
Forty-three men (age 33 +/- 9 yr) with spinal cord injuries (SCI) were observed during a normal workday while heart rate was recorded continuously. Physical strain was estimated using the heart rate response expressed relative to the individual heart rate reserve (%HRR). The mean physical strain during the day for group I (C4-C8, N = 9), II (T1-T5, N = 6),(More)
Six male subjects with spinal cord injuries (SCI) participated in this investigation to compare peak values of oxygen uptake ( $$\dot V$$ O2). heart rate (f c), ventilation ( $$\dot V$$ E), respiratory exchange ratio (R) and power output (W) obtained using a discontinuous (DP) and a continuous jump max protocol (JMP) in a maximal wheelchair exercise test on(More)
This study investigated in rather specific wheelchair tests the relationships among estimates of isometric upper-body strength (Fiso), sprint power (P30), aerobic power (VO2peak), and maximal power output (POaer) in a group of 44 men (age 34 +/- 12 yr) with longstanding spinal cord injuries ranging from C4/C5 to L5. Fiso was defined as the maximum force(More)