Objective quantification of resting and activated parkinsonian rigidity: A comparison of angular impulse and work scores

Effects of STN DBS on Rigidity in Parkinson's Disease

“…The difference may be due to the fact that Relja and colleagues analyzed the data for 103 subjects aged 25-85 years old, while the age of control subjects in our study was 51-72 years old. Fung et al [13] found that an activation maneuver increased the angular impulse in two out of ten controls aged 53-70 years old, while in our experiment W increased in nine out of ten controls. Our results are compatible with those of Kirollos and colleagues [14] who reported that an activation maneuver had a similar effect on PD and elderly controls but did not affect the young control subjects.…”

“…Webster and his colleagues [21], [22], [25] had a torque motor move the forearm over 100° with a constant velocity of 20 deg/s so that the full flexion-extension cycle took 10s to complete. In the later studies, faster oscillations with a frequency of 0.5 Hz over a shorter angular range of 40°-50°w ere used in the elbow experiments [14], [15], and rigidity in the wrist was tested using 1-1.5 Hz sinusoidal oscillations with a ± 30° displacement [13]. In a study of rigidity at the wrist, Teravainen and his colleagues [11] explored a range of waveform parameters: displacements from ± 15° to ± 30°, sinusoidal oscillations with frequencies from 0.2 Hz to 1.6 Hz, and a constant velocity waveform with a range of velocities from 24 to 190 deg/s.…”

“…Activated rigidity refers to a well-known clinical observation that resistance of the passively moved limb increases when the patient is asked to perform a concurrent active movement task with the other limb. In a number of previous studies, calculated mechanical work done by the rigid limb has been used as a quantitative measure of both resting and activated rigidity [11], [13]- [15], [23]- [25].…”

Physiological and Biomechanical Analyses of Rigidity in Parkinson's Disease

“…The underlying approach is to measure the amount of imposed force resistance to externally generated passive movement about the examined joint. The passive movements applied in earlier studies were induced either by a torque motor (Fung et al, 2000;Mak et al, 2007;Shapiro et al, 2007;Watts et al, 1986;Xia et al, 2006) or generated by an examiner to closely resemble a clinical setting (Caligiuri, 1994;Endo et al, 2009;Patrick et al, 2001;Prochazka et al, 1997;Sepehri et al, 2007). Variables described in these previous studies included peak torque (Mak et al, 2007), impulse (i.e., an integral of torque with respect to time; Fung et al, 2000), work score which is calculated as a torque integral with respect to joint angular position (see Fig.…”

Novel Methods to Evaluate Symptoms in Parkinson's Disease – Rigidity and Finger Tappin

“…Rigidity, a well known symptom of PD, is defined as increased muscle tone that is elicited when an examiner moves the patient's limbs, neck, or trunk, and this increased resistance to passive movement is equal in all directions (Fahn & Przedborski 2005). Many researchers have analyzed rigidity by applying biomedical engineering principles and electrophysiological techniques (Fung et al 2000, Prochazka et al 1997, Teravainen et al 1989). However, we do not know exactly what we feel in muscle tone in PD.…”