Is the Timed Up and Go (TUG) Sensitive to Differentiating Patients with Mild to Moderate PD Compared to Age Matched Controls: A Descriptive Pilot Study

Research Article

Phys Med Rehabil Int. 2018; 5(2): 1143.

Is the Timed Up and Go (TUG) Sensitive to Differentiating Patients with Mild to Moderate PD Compared to Age Matched Controls: A Descriptive Pilot Study

Byl N1*, Henry R2, Rizzo R3 and Blum D4

1Professor Emeritus in the UCSF School of Medicine, Department of Physical Therapy and Rehabilitation Science, UCSF/SFSU Graduate Program in Physical Therapy, 1675 Owens St. SF, CA 94158, USA

2Professor in the UCSF School of Medicine, Department of Neurology, Sandler Building, 675 Nelson Rising Ln, SF, CA 94158, USA

3DPT Graduate Student in the UCSF Graduate Division, UCSF/SFSU Graduate Program in Physical Therapy, USA

4Neurologist and Specialist in Parkinson’s Disease in the Pennisula Private Neurology Practice, 418 Willow Rd, Menlo Park, CA 84025, USA

*Corresponding author: Nancy Byl is Professor Emeritus in the UCSF School of Medicine, Department of Physical Therapy and Rehabilitation Science, UCSF/SFSU Graduate Program in Physical Therapy, 1675 Owens St. SF, CA 94158, USA

Received: February 27, 2018; Accepted: March 22, 2018; Published: March 29, 2018


Background: As the population ages, an increasing number of individuals are diagnosed with Parkinson’s Disease (PD), a complex, progressive, neurodegenerative motor and nonmotor disorder which can compromise quality of life/ independence. Given there are no laboratory tests to rule in the disorder, the diagnosis may be delayed until 85% of the dopamine neurons are degenerated. Could the clinical Timed Up and Go (TUG) test serve as an inexpensive, clinical biomarker to help physicians make a diagnosis of PD?

Methods: This descriptive, cross sectional evaluation study included 30 participants (15 with mild to moderate PD [Hoehn and Yahr I-II] and 15 age matched controls. Dependent variables included gender, age, self-reported motor and non-motor impairments paired with standardized measurements of mobility, balance (TUG) and cognition. Seventy percent of participants returned to be tested with the instrumental, dual task TUG (iTUG), the Five Times Sit to Stand Test (FTSTS) and 360o turning. Dependent variables were described (mean and standard deviation) and group differences tested for significance with the Two Sample T Test (P<0.05).

Results: TUG performance was within normal limits with no significant differences between the two groups (7.28 secondsage matched controls and 7.60 secondsPD). In addition, no significant differences were found between the two groups relative to gender, age, pain, fall history or gait speed. However, age matched controls were significantly less depressed, had better balance confidence but reported significantly less physical activity, more medical problems and more prescription medications.

Discussion and Conclusions: The TUG was not a clinically sensitive biomarker to distinguish age matched healthy participants from those with mild-moderate PD who exercised aggressively. The dual task instrumental iTUG variant of the TUG may be more sensitive as a clinical biomarker for distinguishing individuals with early PD from age matched controls.

Keywords: Diagnosis of Parkinson’s disease; Timed up and Go; Clinical biomarker of PD


As our population ages, there is an increasing incidence and prevalence of Parkinson’s Disease (PD). In the United States, the number of persons with Parkinson’s disease is expected to increase from the approximately 340,000 in 2005 to 610,000 in 2030 [1- 4]. Parkinson’s disease is a neurodegenerative condition related to a decrease in dopamine neurons in the substantia nigra [5,6]. By the time a diagnosis is made, there is a loss of up to 50-80% of striatal dopaminergic innervation [7-10]. The underlying disease process of Parkinson’s disease involves destruction of neurons as a consequence of accumulation of protein alpha-synuclein [9]. There is progressive damage to the neural networks in the locus coeruleus, pedunculopontine nucleus (PNN), amygdala, cortical grey matter, peripheral autonomic nerves, as well as the substantia nigra pars compacta [7,9]. This neuroanatomical complexity leads to considerable challenges for effective management [11].

PD is primarily a clinical diagnosis based on a range of motor and non-motor signs and symptoms. Motor signs range from imbalance, festinating gait, asymmetrical arm swing, resting tremor and selfreported stiffness, freezing, falling and loss of balance confidence [12- 14]. Individuals also self-report many non-motor symptoms ranging from sleep disturbance, gastro intestinal discomfort, depression, anxiety, apathy, autonomic dysfunction, cognitive decline, behavioral changes, and loss of sense of smell to name among a few [15]. The impairments are difficult to manage [13] leading to higher mortality, disability and dementia than in age matched controls [16,17]. The lack of clear clinical biomarkers for PD has made it difficult to make an early diagnosis, objectively monitor response to treatment and minimize secondary complications such as falling, physical immobility, depression , loss of community independence and cognitive decline [18,19].

Today, the diagnosis of PD is made clinically [20-22]. The diagnosis is based on a combination of objective and self-reported motor and non-motor factors [23]. Some clinicians and scientists propose by integrating neural biomarkers and genetics, an earlier and more accurate diagnosis of PD could be made in elders and high risk populations [24]. It is possible; an early diagnosis could lead to more effective non-pharmacological management strategies as well as delay the need for medications and possibly deep brain stimulation [25-27]. For example, there is increasing evidence that life style modifications (e.g. nutrition, hydration, physical exercise, sleep, stress management, social interactions, cognitive learning) can minimize the degenerative effects associated with aging and the risk of Alzheimer’s Disease and PD [28-35]. Preventive broad based intervention strategies may also be able to reduce excessive weight, metabolic disease, organ failure and cancer as well as maintain cardiopulmonary and musculoskeletal health, upregulate BDNF, excite dopamine neurons, increase oxygen delivery, minimize plaque deposition, maintain the length of our telomeres and stimulate adaptive cortical synaptic connections to drive positive neural plasticity and responsiveness of the nervous system in our aging population [36-41].

When the diagnosis of PD is confirmed, the primary intervention includes a prescription of dopaminergic medications. The objective of treatment is to minimize the motor and non-motor signs/ symptoms of PD, prevent physical inactivity, decrease falls, provide neuroprotection and maintain functional independence despite potential disease progression. While medications address some of the motor and non-motor symptoms of the disease, these medications can become addictive [42] and they do not predictably produce disease modifying effects [43]. In fact, while some of the motor and non-motor symptoms of Parkinson’s disease are improved with dopaminergic therapy, others are minimally altered (e.g. depression, gastrointestinal dysfunction, orthostatic hypotension, cognitive dysfunction, freezing of gait, balance) [44]. Further, over time, some of these medications can lead to new impairments such as dyskinesias and dystonic movements [45,46].

While there is increasing evidence PD is associated with early changes in neural structure, at this time, bioimaging is not considered a traditional diagnostic test for PD. Although informative structural information can be obtained from magnetic resonance imaging and F=dopa PE, it is not clear which imaging markers are most reliable for assessing clinical severity and rate of progression for PD [47-51]. Consequently, clinicians are left making the diagnosis of PD based on a thorough history, a detailed physical examination and clinical measurements.

Clinical measurements of balance are usually administered as part of the diagnostic procedures for PD. These measurements are also used to monitor the effectiveness of different intervention strategies. Thus, clinicians need reliable and sensitive clinical diagnostic PD measurements to facilitate the ability to make an early diagnosis of PD. The question is whether a common, standardized clinical balance test, the Timed Up and Go Test (TUG), [52-54] is sensitive to discriminate individuals with mild to moderate PD (on dopaminergic medications) from healthy age matched controls. For this small pilot study, the null hypothesis was there would be no significant differences in performance on the TUG for age matched controls and individuals with mild to moderate PD managed with dopamine medications.



Individuals with mild to moderate PD were referred to participate in this pilot study from a neurologist in the private practice of Neurology, physical therapists in the Faculty Physical Therapy Practice and the Health and Wellness Center, University of California, San Francisco, School of Medicine (UCSF) and neurologists caring for patients in the UCSF Department of Neurology, Movement Disorders Clinic. The inclusion criteria were individuals: 1) diagnosed by a neurologist with mild to moderate PD (Hoehn and Yahr I-III) , managed with dopaminergic medications; 2) 21- 80 years of age; 3) male or female; 4) able to come to UCSF for testing; 5) able to understand and carry out instructions in English or come with an interpreter; 6) walk independently with or without an assistive device; 7) were considered medically stable relative to other health problems; and 8) did not suffer any other neurological disease. The exclusionary criteria included individuals: 1) with a neurological disease other than PD; 2) medically unstable cardiovascular, pulmonary, psychiatric or medical illnesses; 3) unable to walk independently (with or without an assistive device); and 4) unable to communicate in English or come with an interpreter. Age matched control subjects were recruited from family members of participants with PD, UCSF faculty members and staff and community members who heard about the study.

This study was approved by the UCSF Committee on Human Research. Seventeen participants with mild to moderate PD and17 healthy, age matched controls provided signed consent to participate prior to baseline testing.


Each participant completed a series of measurements based on scales, questionnaires and a self-reported medical history. The medical history included the self-report measures including Beck Depression Scale (BDI), Activity Balance Confidence Scale (ABC), Freezing of Gait Questionnaire, (FOG) Visual Analog Scale for Pain (VAS) [55], fall history in the last 3 months and the Physical Performance Test (PPT) [43]. In addition, standardized, performance based clinical tests of balance were administered (Timed up and Go [TUG]; selected components of the Berg Balance Scale [Functional Reach, 360o turning time, alternating foot to step, tandem standing and one foot standing with eyes open]), mobility (10 Meter Walk and Tinetti Gait Assessment [43,56]. The performance tests were administered by a blinded evaluator. All participants with PD were tested “on medication”. On the Tinetti Gait Assessment, one criteria was added: Symmetry of Arm Swing (2=symmetric; 1.0 near symmetric; and 0= absent symmetric arm swing [unilateral arm swing] bringing the total score to 14). The participants were asked to return for a second visit to complete the instrumental, dual task Timed up and Go (iTUG) [57] and Five Times Sit to Stand (FTSTS) [58].

The blinded evaluator was a physical therapist or a research assistant trained by the physical therapist and blinded to group assignment. Defined procedures were followed for each of the standardized tests. Participants were video-taped while walking during the 10 meter walk. The videotaped evaluation was used as a reference for the evaluator and the research assistant to administer the Tinetti Gait Inventory. Each rater independently applied the Tinetti criteria for gait quality with the two scores averaged for data analysis.

Each participant who returned for additional balance testing was videotaped while performing the iTUG [57] with and without dual tasking (e.g. carrying a cup of water and then counting backwards). Using a lap stopwatch (Ultrak496), two research assistants, blinded to group assignment, repeatedly viewed the video tapes and timed the components until inter rater agreement was reached within 5 milliseconds for the total score.

The evaluator calculated the scores for all the independent variables. In addition, the evaluator entered the data into Excel (Microsoft) computer files. The accuracy of the scoring and the accuracy of the data entry were checked by the principal investigator.

Study design and data analysis

This was a cross sectional, study with two groups of participants. The two groups of subjects were compared descriptively on all dependent variables (mean and standard deviation). The differences in the descriptive variables for the two groups were evaluated for significance using the Two Sample Student T Test (p<0.05).

The primary dependent variable of interest was the TUG score (total time in seconds). The TUG scores were compared to age norms with differences between the two groups tested for significance with the Two Sample Student t Test. (p<0.05) Excel: Mac,2011 was used for data analysis.


Description of differences in participant groups

Seventeen participants with dopamine managed mild-moderate PD (H & Y I-II) and 17 ages matched healthy participants (AMH) were recruited to the study. Two participants in each group were recruited by phone but then were unable to come for the evaluation session. Thus, 15 participants in each group completed planned study measurements. Seventy percent of the consented participants agreed to return for an additional visit for additional balance measurements (Five Times Sit to Stand and iTUG) [59].

For the participants with PD, the average time since the PD diagnosis was 2.87 (2.07) years with a mean Hoehn and Yahr Scale of 1.13 (0.36) and a mean score on the Freezing of Gait of 3.42 (11.69). All of the participants with PD had a Hoehn and Yahr scale of I or II. The age matched participants and those with PD were similar in age and gender and there were no significant differences between the two groups in terms of falls in the last 3 months, severity of pain, number of painful areas and the number of over the counter medications. However, compared to participants with PD, age matched participants self-reported significantly less depression (BDI score of 3.0age matched controls and 6.97PD), significantly higher ABC balance score (96.2%age matched controls versus 87.9%PD) and performed significantly less intense, regular physical exercise (minutes/week of 201.3 age matched controls and 316 PD). In addition, healthy age matched participants selfreported significantly more medical problems (4.27agematched and 2.89 PD) and indicated they were taking significantly more prescription drugs (4.8age matched and 2.6,PD) than participants with PD (Tables 1 and 2).