Time courses of adaptation in lumbar extensor performance of patients with a single-level microdiscectomy during a physical therapy exercise program.
METHODS
Longitudinal single-cohort study.


OBJECTIVE
To characterize the time course of performance adaptations during a postsurgical exercise intervention following a single-level microdiscectomy.


BACKGROUND
Patients with a recent history of lumbar microdiscectomy are functionally limited, weak, have compromised paraspinal musculature, and benefit from an exercise program.


METHODS
Patients (n = 48) with a single-level microdiscectomy participated in a 12-week (36 sessions) comprehensive strength and endurance exercise program starting 4 to 6 weeks postsurgery. Lumbar extensor strength was quantified as the degree from horizontal on a modified Sorensen test procedure. Patients unable to assume the horizontal position were assumed to have strength deficits. Lumbar muscular endurance performance was quantified by the amount of time patients could hold the Sorensen test position at the horizontal. The time rate of lumbar muscular endurance adaptations were analyzed using longitudinal growth curve modeling.


RESULTS
The adherence rate of this program was low (67%). Twenty percent of the patients were identified as having strength deficits. These deficits were corrected in all patients within 3 to 9 weeks. Linear mixed-model results suggest an improvement of 5.6 seconds in hold time per week of exercise. Both the initial level of endurance and the rates of improvements were highly individualized.


CONCLUSIONS
The time course of musculoskeletal performance adaptations in persons with a history of lumbar surgery is highly individualized. When compared to normative endurance times, the results of this study indicate that the number of sessions and duration of therapy needed to generate meaningful adaptations of the paraspinal musculature is longer than what is typically provided in the clinic postsurgery.


METHODS
Therapy, level 4.J Orthop Sports Phys Ther 2010;40(6):336-344, Epub 13 May 2010. doi:10.2519/jospt.2010.3141.
Flanagan
Sean P
SP
California State University, Northridge, Department of Kinesiology, Northridge, CA 91330-8287, USA. sean.flanagan@csun.edu
Kulig
Kornelia
K
Clinresnet
Pt
P
D000222:Adaptation, Physiological; D000328:Adult; D015331:Cohort Studies; D017586:Diskectomy; D005081:Exercise Therapy / Q000295:instrumentation / Q000379:methods*; D005260:Female; D006801:Humans; D007405:Intervertebral Disc Displacement / Q000601:surgery; D016014:Linear Models; D008137:Longitudinal Studies; D008159:Lumbar Vertebrae / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength; D018908:Muscle Weakness / Q000534:rehabilitation*; D010807:Physical Endurance; D011182:Postoperative Care