Variation of hamstrings lengths and velocities with walking speed.
Crouch gait, one of the most prevalent movement abnormalities among children with cerebral palsy, is frequently treated with surgical lengthening of the hamstrings. To assist in surgical planning many clinical centers use musculoskeletal modeling to help determine if a patient's hamstrings are shorter or lengthen more slowly than during unimpaired gait. However, some subjects with crouch gait walk slowly, and gait speed may affect peak hamstring lengths and lengthening velocities. The purpose of this study was to evaluate the effects of walking speed on hamstrings lengths and velocities in a group of unimpaired subjects over a large range of speeds and to determine if evaluating subjects with crouch gait using speed matched controls alters subjects' characterization as having "short" or "slow" hamstrings. We examined 39 unimpaired subjects who walked at five different speeds. These subjects served as speed-matched controls for comparison to 74 subjects with cerebral palsy who walked in crouch gait. Our analysis revealed that peak hamstrings length and peak lengthening velocity in unimpaired subjects increased significantly with increasing walking speed. Fewer subjects with cerebral palsy were categorized as having hamstrings that were "short" (31/74) or "slow" (38/74) using a speed-matched control protocol compared to a non-speed-matched protocol (35/74 "short", 47/74 "slow"). Evaluation of patients with cerebral palsy using speed-matched controls alters and may improve selection of patients for hamstrings lengthening procedures.
Agarwal-Harding
Kiran J
KJ
Departments of Mechanical Engineering and Bioengineering, Stanford University, Clark Center, Room S-321, Mail Code 5450, 318 Campus Drive, Stanford, CA 94305-5450, USA.
Schwartz
Michael H
MH
Delp
Scott L
SL
D002648:Child; D003198:Computer Simulation; D005260:Female; D005684:Gait; D020233:Gait Disorders, Neurologic / Q000503:physiopathology*; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology*; D008297:Male; D008954:Models, Biological; D018482:Muscle, Skeletal / Q000503:physiopathology*; D005082:Physical Exertion; D013710:Tendons / Q000503:physiopathology*; D016138:Walking
IEEE Trans Biomed Eng. 1990 Aug;37(8):757-67
2210784
J Pediatr Orthop. 1999 May-Jun;19(3):366-75
10344322
Gait Posture. 2007 Oct;26(4):532-8
17208000
J Pediatr Orthop. 1993 Nov-Dec;13(6):722-6
8245195
J Pediatr Orthop. 2002 Mar-Apr;22(2):169-72
11856923
Int Orthop. 1980;3(4):305-9
7399771
Clin Orthop Relat Res. 1992 Nov;(284):247-59
1395302
J Bone Joint Surg Am. 1971 Dec;53(8):1489-510
5121791
Dev Med Child Neurol. 2001 Dec;43(12):802-5
11769265
Gait Posture. 2006 Apr;23(3):273-81
15964759
J Biomech. 2006;39(8):1498-506
15923009
Clin Orthop Relat Res. 1990 Apr;(253):45-54
2317990
J Biomech. 2008;41(8):1639-50
18466909
J Bone Joint Surg Br. 1973 Nov;55(4):822-7
4766188
Gait Posture. 2007 Oct;26(4):546-52
17229573
Gait Posture. 2003 Apr;17(2):113-8
12633770
J Pediatr Orthop. 1998 Nov-Dec;18(6):712-8
9821124
J Orthop Res. 1996 Jan;14(1):144-51
8618157
Ann Biomed Eng. 2001 Mar;29(3):263-74
11310788
J Orthop Res. 1997 Jul;15(4):615-21
9379273
Gait Posture. 2009 Jun;29(4):640-4
19230672
J Biomech. 2009 Jan 5;42(1):77-81
19062018
Clin Orthop Relat Res. 1993 Mar;(288):139-47
8458127
J Biomech. 1999 Feb;32(2):129-34
10052917
J Pediatr Orthop. 2002 Mar-Apr;22(2):158-64
11856921