Effect of Handrail Shape on the Load of Leg in Stepping Stairs

Transcription

1 Effect of Handrail Shape on the Load of Leg in Stepping Stairs Yutaka KURITA, The University of Shiga Prefecture, 5 Hassaka-cho, Hikone, Shiga, Yuichi MATSUMURA, The University of Shiga Prefecture Akihiro TANABE, The University of Shiga Prefecture The effect of a handrail was clarified by evaluating the load of leg in stepping stairs by the sum of the moments of knee and ankle. When body is supported by a handrail, the center of gravity goes backward, and the angle of shank decreases. From the result of experiment, it was proven that there was an optimum value respectively for the height and the position of a handrail. And, we made the mechanism model which can expresses the movement of each part of the body in stepping stairs, based on geometric relation. Key Words: Human Engineering, Biomechanics, Bio-Motion, Handrail for Stairs, Physical Exercise Fig.A1 M 1 =F(Lsin-l) M =Fl M M=FLsin Fig.A 35 Fig.A(a) Fig.A (b) Fig.A(b) Fig.A(c) Fig.A3 Fig.A3 (a) Fig.A3 (b) (1) () (a)with handrail-deg (b)with handrail-35deg (c) Fig.A Effect of handrail in going up stairs Fig.A1 M=FLsin M 1 :Moment about knee M :Moment about heel FForce from floor Angle of shank LShank length ldistance between force from floor and ankle Measurement of the load which is charged on the leg 5 1 (a) (b)with handrail Fig.A3 The center of gravity position in going up stairs

2 (1)() M=FLsin M 1 :Moment about knee M :Moment about heel FForce from floor Angle of shank LShank length ldistance between force from floor and ankle (3)(4) Fig.1(a) F L l M 1 =F(Lsin-l) M =Fl M M=FLsin Fig.1(b) F L M =FL cos M 1 =F(Lsin 1 - L cos ) 1 =+ M=FLsin 1 Fig.(a) 3mm Fig.(b) (5) 1 76N =.48m 8 (a) Up stairs M=FLsin 1 ( 1 =+ ) (a) Measurement of force which leans against handrail Fig.1 M 1 :Moment about knee M :Moment about heel FForce from floor Angle of shank Angle of foot L 1 Shank length L Foot length (b) Down stairs Measurement of the load which is charged on the leg (b) Measurement of reaction force from floor and the angle of leg Fig. Measurement device

3 Fig.3 9mm mm 35 Fig.3(a) Fig.3(b) Fig.3(b) Fig.3(c) Fig.4 (6) Fig.4 (a) Fig.4 (b) Fig.5 Fig.5 76N (a)with handrail - deg (b)with handrail - 35deg (c) Fig.3 Effect of handrail in going up stairs 1 Fig mm mm Fig Fig.7 Fig.7 Force [N] (a) (b) With handrail Fig.4 The center of gravity position in going up stairs Leg Force [N] (a) Fig Hand+Leg Leg Hand (b)with handrail Reason why the ground reaction force decreases

4 5 Fig.8 15mm mm Fig.8 9mm 3 1 9mm 8mm 9mm Fig.8 15mm 3 Fig.9 9mm 15mm Fig.9 15mm mm Fig.1 Fig Handrail position at mm Fig.6 Effect of handrail angle Handrail position at 15mm Handrail position at mm Handrail height [mm] Fig.8 Effect of handrail height Knee angle [deg] Hand force [N] Handrail angle [deg] Fig.7 The factor in which the load of the leg decreases With handrail Handrail height at 9mm Height [mm] Fig.9 Effect of step height

5 Fig.11 9mm mm Fig.11 1 N N 1 (a) 1mm (b) mm (c) 3mm Fig.1 Relation between the angle of shank and the level of stair (a) (b)with handrail Fig.11 Effect of handrail in going down stairs Fig.1 8mm 85mm9mm mm Fig (7) Fig.13 G l 1 l l 3 l 4 h l 5 ( l 1 + l + l4 ) cosα = l1 sin β + l cosθ + hááááááá (1) ( l 1 + l + l4 ) sinα + l1 cos β = l sinθ + l5 ÁÁÁÁÁÁ Á() (1)() l 1 +l +l 4 =L [ L( h cosα + l sin α ) l ( h cosθ + l sin θ ) + l L cos( α θ )] = L l 1 + l 5 + l 5 + h Handrail height at 9mm Handrail height at 85mm Handrail height at 8mm (3) Hand position [mm] Fig.1 Effect of handrail height 5 ÁÁÁÁÁÁÁÁÁÁÁÁÁ

6 GCenter of gravity l Thigh length l Shank length l 3 Distance between waist and center of gravity l 4 Distance between heel and floor l 5 Distance between foreleg and hind leg hheight of step Angle of shank Angle of hind leg Angle of thigh Fig.13 Mechanism model Angle θ [deg] mm step(experiment) mm step(experiment) 3mm step(experiment) 3mm mm 1mm Center of gravity position [mm] Fig.15 Relation of center of gravity and shank angle (a)effect of handrail (b)handrail position (c)step height Fig.14 The posture in going up stairs (3) h G Fig.14(a) (3) Fig.14(b) (3) l 1 +l +l 3 + l Fig.14(c)(3) h Fig.15 mm l 1 =.5m l =.48m l 4 =.5m 1mm mm 3mm 3mm (1) () mm (3) 1 (1) (1999)1-11 () (3) (1999) (4) (199) (5) 4 (1978) (6) (7) (1999)19-8