Musculoskeletal disorders are among the most frequently occurring chronic conditions that affect the general population and substantially impact physical activity, mental state, and quality of life (QOL) (Bingefors and Isacson, 2004; Lawrence et al., 1998). Musculoskeletal disorders become more prevalent with age, and they are the leading cause of disability (Lawrence et al., 2008; Picavet and Hazes, 2003). The management goals of patients with musculoskeletal disorders are no longer limited to reducing signs and symptoms but now includes increasing function (Dieppe, 2004). There is a current trend to enhance general well-being or QOL, which involves integrating patient-centric perspectives and comprehensive assessment of intervention outcomes (Furner et al., 2011; Gruber et al., 2010; Menz et al., 2010).

A growing number of outcome instruments have been introduced to evaluate upper limb function and disability (Oh et al., 2009; Romeo et al., 1996). These instruments range from objective measures, such as range of motion (ROM) (Constant and Murley, 1987) or muscle strength (Constant and Murley, 1987; Roh et al., 2012e), to more subjective measures, such as patient satisfaction (Monnin and Perneger, 2002) or quality of life (Goldhahn et al., 2008; van de Ven-Stevens et al., 2009). Impairments such as muscle weakness or limitation in range of motion may have a comprehensive impact on daily life. For instance, grip strength has a critical role during the performance of daily activities, and is considered an important measure of recovery after upper extremity injuries and for the evaluation of treatment outcomes. However, the degree of satisfaction regarding function or disability differs across patients, and this inter-patient variability in self-assessment is important to consider in the clinical evaluation of upper limb function. In clinical studies, recent trend has been to move toward patient-based (patient-centric) instruments and away from clinician-based (performance based) ones, the letter of which is more susceptible to observer bias and error and does not represent illness/disability experience of patients themselves (Harvie et al., 2005). Furthermore, outcome assessments include measures of impairment or disability as well as measures of general health-related QOL, in order to assess the full impact of problem related to a certain upper limb condition.

There are many outcome instruments available for assessment of upper limb functions. These are not standardized or unclear. The purpose of this paper is to review outcome measures of upper limb function, which can be categorized as patient- or clinician-based, and as condition specific or general health related QOL evaluations. In addition, we discuss clinical research considerations in selection/interpretation of instruments for upper limb functions. The upper limb outcome instruments reviewed in this article include the Michigan hand questionnaire (MHQ), the Patient-rated wrist evaluation score (PRWE), the Constant-Murley score, the simple shoulder test (SST) the Oxford shoulder score (OSS,) the disability of arm, shoulder and hand questionnaire (DASH), and the short form- 36 health survey (SF-36).

On one hand, condition-specific instruments of musculoskeletal disorders measure symptoms and disabilities relevant to specific conditions and are useful for assessing responses to treatments. On the other hand, general health status instruments measure multiple aspects of health, including physical function, mental health, and social function. Although generic measures may not be as sensitive to the disability experienced by patients, general health status measurements generally correlate with condition-specific instruments that address musculoskeletal manifestation (Ostendorf et al., 2004; SooHoo et al., 2002). This implies that musculoskeletal complaints influence general health status and that a considerable proportion of variation in general health status can be attributed to regional musculoskeletal disability.

To evaluate upper limb impairment or disability, reliable and validated outcome measures should take into account all aspects of a patient’s life that may be affected by the presence of the disability or impairment. Most investigators support the use of condition specific measures along with generic measures. The former include items relevant and sensitive to the disorder being studied, and the latter allow for comparisons between conditions and may be sensitive to unexpected consequences of a disorder. Investigators should select a proper instrument with established validity and reliability. All things being equal, the most responsive instrument available should be used in order to minimize the sample size for the proposed study. Therefore, additional information is required to understand how sensitive these instruments are to clinical change in function experienced by patients who have problems over time.

Psychologic distress, such as pain-induced anxiety or depression, is increasingly recognized as contributing to pain and disability perception in several musculoskeletal disorders (Kim et al., 2011; Roh et al., 2012d). Depression has been reported to be highly prevalent in the elderly and consistently contributes to symptom severity in some musculoskeletal disorders (Roh et al., 2012b; Rosemann et al., 2007; Salaffi et al., 1991) Furthermore, subjective factors, such as pain and depression, have been reported to have greater influences when disability is measured with respect to functions related to the entire upper extremity, i.e. DASH scores, rather than with respect to a more specific regional site (Lindenhovius et al., 2008). A large variability in DASH scores in upper-extremity disorders was found to arise from psychosocial rather than physical factors (Ring et al., 2006).

Female subjects are known to report higher level of musculoskeletal pain and disability, although objective findings, such as range of motion and abduction strength, did not differ between the genders (Roh et al., 2012a; Roh et al., 2012d). Musculoskeletal pain or disability has been reported to be both more prevalent (Leveille et al., 2005) and worse in women (Bingefors and Isacson, 2004), which could be due to a higher physical vulnerability (Wijnhoven et al., 2006) or sensitivity to pain (Wolfe et al., 1995) in the gender. This gender-specific effect was reported not to be confined to a specific physical subscale but rather involved all physical components of SF-36 and DASH.

Functional assessment is also influenced by the prevalence of degenerative musculoskeletal disorders such as osteoarthritis and rotator cuff disease. In individuals older than 65 yr, osteoarthritis of the knees and hands and rotator cuff diseases are the most prevalent causes of musculoskeletal pain. A high prevalence of these degenerative musculoskeletal diseases has been previously demonstrated (Picavet and Hazes, 2003), and prevalence of concurrent upper and lower extremity pain in those older than 65 yr is estimated to be greater than 40% (Scudds and Robertson, 2000).

Much progress has been made in validation of functional assessment of upper limb conditions, and currently there is a growing number of instruments for each of the main groups of upper limb conditions. The upper limb instruments reviewed in this article allow for assessments of various aspects of functional problems related to upper limb conditions. Furthermore, functional outcome measures of upper limb are affected by differences in cultural, psychological, and gender aspects of illness perception and behavior. Therefore, comprehensive assessment of upper limb function requires measures of impairment or disability as well as generic measures of health-related QOL. Standardized assessments of regional musculoskeletal disabilities and general health status may help clinician in treatment decision-making and in interpretation of treatment outcomes of upper limb conditions. Clinicians and researchers should be aware of the characteristics of each outcome instrument and select the upper limb outcome instruments which most appropriately address the primary purpose of a given research.