Physical performance measurement in persons with patellofemoral osteoarthritis: A pilot study.

BACKGROUND: Patellofemoral osteoarthritis (PFOA) is associated with pain and decreased self-reported function. The impact of PFOA on actual physical performance is currently unknown. OBJECTIVE: To investigate the impact of PFOA on physical performance and pain. METHODS: Eight participants aged 40-65 years with bilateral, symptomatic, radiographic PFOA and 7 age- and gender-matched pain-free control participants without radiographic PFOA were studied. Physical performance was measured with the Timed-Up-and-Go (TUG) and 50-foot Fast-Paced-Walk (FPW) tests. Dependent variables included time to complete the TUG and FPW; pretest-posttest change in pain intensity (TUG and FPW); and self-reports of perceived knee pain, stiffness, and physical function. Data were analyzed with nonparametric statistics. RESULTS: The PFOA group TUG time was longer than the control group (p=0.01). No difference between groups was found for FPW time. Pretest-posttest pain increased for the TUG and FPW in PFOA participants (p< 0.05). The PFOA group reported greater knee pain, stiffness, and less physical function than controls (previous 48 hours) (p < 0.01). CONCLUSIONS: Symptomatic, radiographic PFOA is associated with increased pain during the TUG and FPW tests and longer time required to complete the TUG. The TUG may be a more sensitive test of physical performance in PFOA.

Frontal plane knee and hip kinematics during sit-to-stand and proximal lower extremity strength in persons with patellofemoral osteoarthritis: a pilot study.

Increased joint stress and malalignment are etiologic factors in osteoarthritis. Static tibiofemoral frontal plane malalignment is associated with patellofemoral osteoarthritis (PFOA). Patellofemoral joint stress is increased by activities such as sit-to-stand (STS); this stress may be even greater if dynamic frontal plane tibiofemoral malalignment occurs. If hip muscle or quadriceps weakness is present in persons with PFOA, aberrant tibiofemoral frontal plane movement may occur, with increased patellofemoral stress. No studies have investigated frontal plane tibiofemoral and hip kinematics during STS in persons with PFOA or the relationship of hip muscle and quadriceps strength to these motions. Eight PFOA and seven control subjects performed STS from a stool during three-dimensional motion capture. Hip muscle and quadriceps strength were measured as peak isometric force. The PFOA group demonstrated increased peak tibial abduction angles during STS, and decreased hip abductor, hip extensor, and quadriceps peak force versus controls. A moderate inverse relationship between peak tibial abduction angle and peak hip abductor force was present. No difference between groups was found for peak hip adduction angle or peak hip external rotator force. Dynamic tibiofemoral malalignment and proximal lower extremity weakness may cause increased patellofemoral stress and may contribute to PFOA incidence or progression.

Correlations among measures of knee stiffness, gait performance and complaints in individuals with knee osteoarthritis.

BACKGROUND: Stiffness is a common complaint in individuals with knee osteoarthritis and is a component of the osteoarthritis diagnosis. Yet the relationship between stiffness and function is poorly understood and methods to quantify stiffness are limited. METHODS: Using a cross-sectional observational design with 66 subjects with knee osteoarthritis, stiffness and damping coefficients were calculated from a relaxed knee oscillation procedure. Gait parameters were measured using an electronic walkway. Self-reported pain, stiffness, and function were measured with the Western Ontario and McMaster Osteoarthritis Index. Correlation and Alexander's normalized-t approximation analyses were used to assess associations among the variables. Subset analysis was performed on subjects with and without tibiofemoral joint crepitus. FINDINGS: Slight to moderate correlations existed between stiffness and damping coefficients and most gait parameters ((| r |=0.30-0.56; P<.05) and between Western Ontario and McMaster Osteoarthritis Index scores and all gait parameters (| r |=0.35-0.62; P<.05). The damping coefficient was only slightly associated with patient-rated Western Ontario and McMaster Osteoarthritis Index stiffness subscale scores. Subset analysis revealed significant correlations that differed between those with and without crepitus. INTERPRETATION: These findings suggest that laboratory measured stiffness and damping coefficients, Western Ontario and McMaster Osteoarthritis Index scores and gait-related measurements assess different aspects related to movement in individuals with knee osteoarthritis. Stiffness and damping coefficients may offer the ability to explain gait changes in the knee that are independent of a person's perceptions particularly in the early stages of the disease.

Implications for rehabilitation after total wrist arthroplasty.

Achieving satisfactory, long-term functional outcomes after total wrist arthroplasty surgery has proved more complicated than with arthroplasties in joints such as the hip or knee. However, improvements in implant design and surgical technique have resulted in recent successes and evidence that wrist arthroplasty may be an appropriate choice to improve function in select patients. This article reviews factors that therapists must consider in planning, implementing, and progressing individual patients' rehabilitation programs after wrist arthroplasty surgery. Therapists must be knowledgeable about the specifics of each patient's surgery so that the rehabilitation program can be customized appropriately and can contribute to achieving pain-free stable wrist movement that allows patients to perform their desired functional activities.