Quantitative analysis of sit to stand movement: Experimental set-up definition and application to healthy and hemiplegic adults M. Galli a,b , V. Cimolin a, * , M. Crivellini a , I. Campanini c a Department of Bioengineering, Politecnico di Milano, P.zza Leonardo da Vinci 32, 20133 Milano, Italy b IRCCS ‘‘San Raffaele Pisana’’, Casa di Cura ‘‘San Raffaele Cassino’’, Tosinvest Sanita `, Rome, Italy c LAM, Rehabilitation Department, AUSL Reggio Emilia, Italy Received 5 July 2006; received in revised form 5 October 2007; accepted 13 October 2007 Abstract Rising from a chair or sit to stand (STS) is a movement with a great clinical interest: it is meaningful in order to evaluate motor control and stability in patients with functional limitations. STS requires some skills, as coordination between trunk and lower limbs movements, correction of muscles strength, control of equilibrium and stability and it is often considered into clinical evaluation scales of different pathologies. In literature, although some studies are focused on STS, the essential functions of standing up are not well standardized and uniformly defined: for this reason its application in clinical centres is difficult. In this study an experimental set-up for acquisition of STS movement which is suitable for clinical applications has been proposed: first, it was studied in healthy subjects, to define a normative database of this specific motor task, then in pathological subjects (adults with hemiplegia), to quantify their functional limitation, using quantitative kinematic and kinetic parameters. The results showed that this experimental set-up is effective both in healthy and in pathological subjects; some significant parameters were identified and calculated in order to characterise and quantify the functional limitation of patients. # 2007 Elsevier B.V. All rights reserved. Keywords: Sit to stand; Kinematics; Kinetics; Hemiplegia; Rehabilitation 1. Introduction Sit to stand (STS) is one of the most common movements of daily life [1]. Rising from the seated position is a complex activity: it requires an adequate postural control during the motor transfer from a stable 3-points base, the sitting position, to a 2-points base, the standing position. Difficulty or inability to stand up is common in individuals with a variety of motor disabilities. STS evaluation is often considered in clinical evaluation scales of different pathologies. The quantitative analysis of STS would, therefore, be worthwhile in quantifying functional limita- tions of patients, in identifying compensatory patterns, in selecting rehabilitative programs and in improving ther- apeutic interventions. Studies on STS have been conducted mainly in healthy subjects [1–11]; few studies exist on pathological subjects [12–15]. The main features of previous studies are reported in Table 1, showing analyses conducted using different techniques and marker configurations, while subjects were allowed to rise under uncontrolled conditions. There is, therefore, a clinical need to define an easily reproducible and well standardized experimental set-up, suitable for patients with motor disabilities. The objectives of this study were as follows: (a) the development of an experimental set-up for the STS, suitable for clinical application; (b) the definition of normative data of STS and the identification and computation of significant kinematic and kinetic parameters; www.elsevier.com/locate/gaitpost Available online at www.sciencedirect.com Gait & Posture 28 (2008) 80–85 * Corresponding author. Tel.: +39 02 23993359; fax: +39 02 23993360. E-mail addresses: manuela.galli@polimi.it (M. Galli), veronica.cimolin@polimi.it (V. Cimolin), marcello.crivellini@polimi.it (M. Crivellini), isabella.campanini@ausl.re.it (I. Campanini). 0966-6362/$ – see front matter # 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.gaitpost.2007.10.003