- Email: [email protected]
AGING EFFECT ON MOVEMENT OF PREHENSION WITH OBSTACLE
Presentation 0742, Gait and Balance 2 – Obstruction or Cognitive Perturbation on Gait. 16:45, Room 101CD
S168
AGING EFFECT ON MOVEMENT OF PREHENSION WITH OBSTACLE M Geronimi and P Gorce Laboratoire Handibio - ESP EA 3162 - Université du Sud Toulon-Var - France Email: [email protected] and [email protected]
METHODS Twenty male with 15 young adults between 18 to 35 years (mean: 25.75 years +/- 4.41) and 5 senior adults between 65 to 74 years (mean: 69.5 years +/- 6.36) participate at the experimentation. All present a dominance of the right hand and a good vision. No neurological pathology or engraves lesion on upper member were declared. A Cyberglove (Virtual Technologies, Alto Palo, CA) is used to record hand and digits right movements. A twelve typical postures procedure are performed by each participant to calibrate the data glove. 3D movements of the wrist are recorded thanks to an electromagnetic sensor (The Flock of Birds, Ascension Technology, Inc, Burlington, Vermont, USA). The sampling frequency is 60 Hz and the recording period is 6 s. The object to be grasped is a polystyrene sphere with a mass fixed to 20g and a diameter to 5.5 cm, placed at 50 cm in front of the participant. Different obstacle sizes (10, 15 and 20 cm) and width (3, 7 and 15 cm) are successively placed at 15 or 25 cm between the subject and the object. It is asked at the subject to grasp the object presented and to put it in a final position without moving or touching the obstacle. Each subject performs 39 trials (2 x 9 obstacles x 2 positions + 3 controls) in a randomised order. The reference condition (control) consists in reaching the object without obstacle. RESULTS In accordance with the literature [1] [2], movement time (MT) appears significantly longer for the obstacle conditions versus without obstacle for the whole of the population. With the elderly subjects, MT mean is 1.79 s +/- 0.45 for the positions with obstacle versus 0.83 s + /- 0.2 without obstacle. With the adult subjects, MT mean to 1.12 s + /- 0.4 was observed for the movements with obstacle versus 0.78 s+/- 0.15 for the movements without obstacle. In obstacle conditions, a significant difference is observed between the two populations (p<0.01) (Fig.1). Elderly MT is characterised by a longer deceleration phase compared to the adults [4]. The maximum height of wrist (Hmax) is significantly bigger for the trials with obstacle versus without obstacle for all the population. With the adults, Hmax increases significantly for the conditions with obstacle vs without obstacle (0.34 m +/- 0.05 vs 0.2 m +/- 0.09). Journal of Biomechanics 40(S2)
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Trajectories of wrist (cm)
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a. 600 Trajectories o f w rist (m m )
INTRODUCTION Effect of obstacle presence on prehension are characterised by an alteration in reaching kinematics and by a modification of grasping organisation [1] [2]. However, as theses studies concerns essentially a population with young adults, the results cannot be objectively extended to the whole of the human population. Indeed, to our knowledge, no data concerning the movement of prehension in perturbed environment for an elderly population are available in the literature whereas aging effect is identified in simple prehension [3] [4]. The aim of this study is to underline, in a biomechanical protocol, the aging effect on movement of prehension with obstacle.
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Figure 1: Typical trajectories of wrist for Adult (a.) and Elderly (b.) during reach-to-grasp movement with obstacle. No significant difference was observed between the elderly subjects and adults. Maximum speed of the wrist (Vmax) appears significantly superior for the conditions with obstacle versus without obstacle. With the elderly subjects, Vmax is to 0.24 m/s +/- 0.06 for the conditions with obstacle versus 0.16 cm/s +/- 0.05 for the conditions without obstacle. With the adult subjects, Vmax is to 0.32 cm/s +/- 0.07 for the conditions with obstacle versus 0.26 m/s +/- 0.05 for the conditions without obstacle. Vmax appears significantly bigger for the adult subjects than for the elderly subjects for all conditions (p<0.01). CONCLUSIONS This study shows a similar effect of obstacle presence on movement of prehension with obstacle for adults and elderly. Amplitude differences are observed between adult and elderly populations in accordance with results in simple prehension condition [3]. Causes may be explain by a combination of local structural changes (joints, muscle, tendon, bone, nerve and receptors, blood supply, skin, and fingernails) and more distant changes in neural control [4]. REFERENCES 1. Alberts J, et al. Exp Brain Res, 143, pp. 417-425, 2002. 2. Biegstraate M., et al. Exp Brain Res, 149, pp. 530-534, 2003. 3. Ranganathan VK, et al. J Am Geriatr Soc, 49(11): 1478-84, 2001. 4. Cooke JD, et al. Neurobiol Aging, 10(2), pp. 159-165, 1989. XXI ISB Congress, Podium Sessions, Monday 2 July 2007
S168
AGING EFFECT ON MOVEMENT OF PREHENSION WITH OBSTACLE M Geronimi and P Gorce Laboratoire Handibio - ESP EA 3162 - Université du Sud Toulon-Var - France Email: [email protected] and [email protected]
METHODS Twenty male with 15 young adults between 18 to 35 years (mean: 25.75 years +/- 4.41) and 5 senior adults between 65 to 74 years (mean: 69.5 years +/- 6.36) participate at the experimentation. All present a dominance of the right hand and a good vision. No neurological pathology or engraves lesion on upper member were declared. A Cyberglove (Virtual Technologies, Alto Palo, CA) is used to record hand and digits right movements. A twelve typical postures procedure are performed by each participant to calibrate the data glove. 3D movements of the wrist are recorded thanks to an electromagnetic sensor (The Flock of Birds, Ascension Technology, Inc, Burlington, Vermont, USA). The sampling frequency is 60 Hz and the recording period is 6 s. The object to be grasped is a polystyrene sphere with a mass fixed to 20g and a diameter to 5.5 cm, placed at 50 cm in front of the participant. Different obstacle sizes (10, 15 and 20 cm) and width (3, 7 and 15 cm) are successively placed at 15 or 25 cm between the subject and the object. It is asked at the subject to grasp the object presented and to put it in a final position without moving or touching the obstacle. Each subject performs 39 trials (2 x 9 obstacles x 2 positions + 3 controls) in a randomised order. The reference condition (control) consists in reaching the object without obstacle. RESULTS In accordance with the literature [1] [2], movement time (MT) appears significantly longer for the obstacle conditions versus without obstacle for the whole of the population. With the elderly subjects, MT mean is 1.79 s +/- 0.45 for the positions with obstacle versus 0.83 s + /- 0.2 without obstacle. With the adult subjects, MT mean to 1.12 s + /- 0.4 was observed for the movements with obstacle versus 0.78 s+/- 0.15 for the movements without obstacle. In obstacle conditions, a significant difference is observed between the two populations (p<0.01) (Fig.1). Elderly MT is characterised by a longer deceleration phase compared to the adults [4]. The maximum height of wrist (Hmax) is significantly bigger for the trials with obstacle versus without obstacle for all the population. With the adults, Hmax increases significantly for the conditions with obstacle vs without obstacle (0.34 m +/- 0.05 vs 0.2 m +/- 0.09). Journal of Biomechanics 40(S2)
600
Trajectories of wrist (cm)
500
400 X
300
Y Z
200
100
0 0
100
200
300
400
500
600
Time (ms)
a. 600 Trajectories o f w rist (m m )
INTRODUCTION Effect of obstacle presence on prehension are characterised by an alteration in reaching kinematics and by a modification of grasping organisation [1] [2]. However, as theses studies concerns essentially a population with young adults, the results cannot be objectively extended to the whole of the human population. Indeed, to our knowledge, no data concerning the movement of prehension in perturbed environment for an elderly population are available in the literature whereas aging effect is identified in simple prehension [3] [4]. The aim of this study is to underline, in a biomechanical protocol, the aging effect on movement of prehension with obstacle.
500 400
X Y
300
Z 200 100 0 0
100
200
300
400
500
600
Time (ms)
b.
Figure 1: Typical trajectories of wrist for Adult (a.) and Elderly (b.) during reach-to-grasp movement with obstacle. No significant difference was observed between the elderly subjects and adults. Maximum speed of the wrist (Vmax) appears significantly superior for the conditions with obstacle versus without obstacle. With the elderly subjects, Vmax is to 0.24 m/s +/- 0.06 for the conditions with obstacle versus 0.16 cm/s +/- 0.05 for the conditions without obstacle. With the adult subjects, Vmax is to 0.32 cm/s +/- 0.07 for the conditions with obstacle versus 0.26 m/s +/- 0.05 for the conditions without obstacle. Vmax appears significantly bigger for the adult subjects than for the elderly subjects for all conditions (p<0.01). CONCLUSIONS This study shows a similar effect of obstacle presence on movement of prehension with obstacle for adults and elderly. Amplitude differences are observed between adult and elderly populations in accordance with results in simple prehension condition [3]. Causes may be explain by a combination of local structural changes (joints, muscle, tendon, bone, nerve and receptors, blood supply, skin, and fingernails) and more distant changes in neural control [4]. REFERENCES 1. Alberts J, et al. Exp Brain Res, 143, pp. 417-425, 2002. 2. Biegstraate M., et al. Exp Brain Res, 149, pp. 530-534, 2003. 3. Ranganathan VK, et al. J Am Geriatr Soc, 49(11): 1478-84, 2001. 4. Cooke JD, et al. Neurobiol Aging, 10(2), pp. 159-165, 1989. XXI ISB Congress, Podium Sessions, Monday 2 July 2007