**5. Conclusions**

The new IRL-HHD has excellent intratester reliability, when used by an experienced user on healthy adults, for measuring peak torque and total work for elbow flexion and knee extension. Therefore, the device and the associated test protocols described in this paper can be used to measure these two physical attributes. The device is only reliable for determining peak torque angle if the mean of at least three repeated measurements is taken.

The LOA between the IRL-HHD and the isokinetic dynamometer are only reasonable for measuring elbow flexion peak torque and work. There were no agreements for peak torque and work of knee extension and peak torque angles of both elbow flexion and knee extension. Therefore, the IRL-HHD cannot be used on large muscle groups, such as the quadriceps, of healthy adults. The LOA also imply that the strength of the assessor using the IRL-HHD constrains the maximum forces that may be exerted by the subject, similar to the constraints reported for other hand-held isometric dynamometers.

The results obtained with the IRL-HHD cannot be compared with those obtained with an isokinetic dynamometer. However, since it has excellent intratester reliability, it can be used to compare strengths of different subjects or of one subject at different times, if used by the same assessor with the same test protocol.

#### **6. Potential usage and future work**

Recently, a study has been published on the reliability of shoulder assessment in patients with shoulder pain using the IRL-HHD (Cadogan et al. (2011)). These results show a good to excellent reliability of the IRL-HHD in practice.

The ability of measuring simultaneously the orientation of the device and the force imposed on the force plate may lead to many other potential usages. Other applications in which the IRL-HHD could be used include:


Future work should concentrate on developing and carrying out clinical trials for measuring the dynamic strength of people with injury or disability, small muscle groups in adult population or all muscle groups in children. For large muscle group assessments, additional fixtures to provide mechanical advantages for the assessors may be a solution for low-cost functional dynamic strength assessment tools.

#### **7. Acknowledgements**

This work was supported by the Foundation for Research Science and Technology, New Zealand (C08X0816). We thank Burwood Academy of Independent Living and the School of Physiotherapy, Otago University for their assistance in this research.

#### **8. References**

12 Will-be-set-by-IN-TECH

Other factors that may affect the IRL-HHD assessments include: discomfort over the anterior tibial region because of the hard padding of the IRL-HHD force plate; the participants might be trying to control the speed; or they might think that the physiotherapist would not be able

The new IRL-HHD has excellent intratester reliability, when used by an experienced user on healthy adults, for measuring peak torque and total work for elbow flexion and knee extension. Therefore, the device and the associated test protocols described in this paper can be used to measure these two physical attributes. The device is only reliable for determining

The LOA between the IRL-HHD and the isokinetic dynamometer are only reasonable for measuring elbow flexion peak torque and work. There were no agreements for peak torque and work of knee extension and peak torque angles of both elbow flexion and knee extension. Therefore, the IRL-HHD cannot be used on large muscle groups, such as the quadriceps, of healthy adults. The LOA also imply that the strength of the assessor using the IRL-HHD constrains the maximum forces that may be exerted by the subject, similar to the constraints

The results obtained with the IRL-HHD cannot be compared with those obtained with an isokinetic dynamometer. However, since it has excellent intratester reliability, it can be used to compare strengths of different subjects or of one subject at different times, if used by the

Recently, a study has been published on the reliability of shoulder assessment in patients with shoulder pain using the IRL-HHD (Cadogan et al. (2011)). These results show a good to

The ability of measuring simultaneously the orientation of the device and the force imposed on the force plate may lead to many other potential usages. Other applications in which the

• In an isometric setting, the device can provide additional feedback on the tested angle. An audible angle warning feature can help the therapist to keep the joint within a pre-defined range, making the assessment more reliable (Sole et al. (2010), Hanna et al. (2010), Fulcher

• In the above described study of shoulder assessment (Cadogan et al. (2011)), a standardized shoulder lateral abduction active end range measurement was introduced. Since the end range of the shoulder is dependent on the amount of force the clinician exerts, it is impossible to compare measurements made by different assessors. However, with the IRL-HHD, a pre-set force can be entered into the IRL-HHD and when the force exerted on the force pad reaches the pre-set level, the IRL-HHD gives an audible warning sound so that the clinician knows when to click a button on the IRL-HHD to record the

angle measurement. This should alleviate the assessors' variable strength issue.

• For measuring joint stiffness. Stiffness is defined as the rate of change of force with respect to the rate of change of displacement. Since the IRL-HHD can measure force and angle

peak torque angle if the mean of at least three repeated measurements is taken.

to control a maximal effort were they to exert it.

reported for other hand-held isometric dynamometers.

same assessor with the same test protocol.

excellent reliability of the IRL-HHD in practice.

simultaneously, it is ideal for measuring stiffness.

**6. Potential usage and future work**

IRL-HHD could be used include:

et al. (2010)).

**5. Conclusions**


**5** 

**Functional Recovery and** 

Thomas Janssen and Karin Gerrits

*VU University Amsterdam,* 

*The Netherlands*

**Muscle Properties After Stroke:** 

**A Preliminary Longitudinal Study** 

Astrid Horstman, Arnold de Haan, Manin Konijnenbelt,

Almost all patients with stroke experience a certain degree of functional recovery within the first six months after stroke. Most recovery of motor and functional performance is seen in the first month after stroke (Gray et al., 1990; Duncan et al., 1992, 1994; Jorgensen et al., 1995; Horgan & Finn, 1997; Kong et al., 2011) but improvement may continue as long as 6–12 months after stroke (Bonita & Beaglehole, 1988). Verheyden et al. (2008) observed most improvement for trunk, arm, leg and functional recovery from 1 week to 1 month after stroke and then to a lesser extent between 1 and 3 months after stroke. Only small, not statistically significant changes could be seen between 3 and 6 months after stroke, indicating that a "plateau phase" was already reached at 3 months after stroke. Further improvement after 6 months can be expected but is mostly limited (Mayo et al., 1999; Hendricks et al., 2002; Desrosiers et al., 2003; Kwakkel et al., 2004). Six months after stroke, only 60% of people with initial hemiparesis have achieved functional independence in simple activities of daily living such as toileting and walking short distances (Mayo et al., 1999; Patel et al., 2000). However, improvements in activities of daily living may continue despite stable deficits at the level of impairment. This is suggestive of further behavioral adaptation or compensation. Rehabilitation is devoted to enlarge and precipitate this functional recovery in order to improve quality of life after stroke (Gresham et al., 1995). Therefore, rehabilitation programs adapted to objectives as allowed by the state of the

Many daily activities, especially locomotion, require sufficient function of thigh muscles. A number of studies reported that lower extremity muscles are weaker in patients with stroke compared to healthy controls (Newham & Hsiao, 2001; Bohannon, 2007b; Sullivan et al., 2007; Horstman et al., 2008). Furthermore, the inability to generate normal amounts of force has been suggested to be the major limitation of physical activity (Mercier & Bourbonnais, 2004; Ada et al., 2006). More specific, intrinsic strength capacity as well as the ability to maximally activate the knee extensors correlate strongly with functional performance (daily activities) in patients with stroke (Bohannon, 1988, 1989; Corrigan & Bohannon, 2001; Kim & Eng, 2003; Bohannon, 2007b; Patterson et al., 2007; Horstman et al., 2008). In addition, a

**1. Introduction** 

neuromuscular system are important.

