The purpose of this study is to assess the course of hip weakness after LLIF or ALIF procedures. These outcomes include measures of hip strength using a dynamometer, which is a device used to measure muscle strength. While it is known that people experience temporary hip and leg weakness after an LLIF or ALIF, the exact timing of when hip and leg strength is regained after an LLIF or ALIF is not known.

Inclusion Criteria:

• 1-, 2-, or 3-level L2L3, L3L4, or L4L5 LLIF or ALIF for degenerative pathology including radiculopathy, neurogenic claudication, intervertebral disc disease, facet joint disease, degenerative spondylolisthesis, degenerative myelopathy degenerative kyphosis, and scoliosis
• Back and/or leg pain
• Failed at least 6 months of conservative treatment

Exclusion Criteria:

• Older than 65 years of age
• Prior spinal fusion surgery
• Greater than Grade 2 spondylolisthesis
• Greater than 10° scoliosis
• History of spinal infection

Patients undergoing LLIF or ALIF procedures