Abstract:
An improved, multiple-use range of motion goniometer ( 20 ) is provided having a handle ( 22 ) and an angle-indicating assembly ( 24 ) having a pair of angle-indicating arms ( 26, 28 ) supported by the handle ( 22 ). Preferably, the goniometer arms ( 26, 28 ) have corresponding circular bases ( 30, 32 ) which are coupled together via a pivot assembly ( 34 ). A secondary, gravity-operated, track and ball range of motion measurement device ( 70 ) is also secured to the bases ( 30, 32 ). An auxiliary base ( 25 ) secured to the handle ( 22 ) and is moveable between a recessed storage position and an extended use position. The outer base ( 30 ) is provided with thumb movement surfaces in the form of apertures ( 56 ), allowing the therapist holding the handle ( 22 ) to rotate the outer base ( 30 ) relative to the inner base ( 32 ) with one hand.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention is broadly concerned with improved, multiple-use goniometers having a handle as well as a dual-arm angle indicating assembly which can be placed adjacent a patient&#39;s joint in order to provide range of motion measurements. The handle supports a pair of elongated angle-indicating arms which can be manipulated by a therapist using only one hand. The preferred goniometer also includes a secondary, gravity-operated, track and ball angle measuring device, as well as an auxiliary base. 
         [0003]    2. Description of the Prior Art 
         [0004]    Goniometers are instruments which measure the range or extent of movement of flexing joints such as the knee, ankle, wrist, shoulders, hips, and fingers. These devices are commonly used during the course of therapy after injuries or illnesses which affect joint movement, in order to provide an indicator of the extent of the patient&#39;s recovery. Generally available present-day goniometers are simple instruments having two arms hinged together with an angular scale. In use, the arms are positioned in alignment with the body parts adjacent to the joint, and the patient then flexes the joint. A second, followup measurement is taken at a subsequent session. The second measurement is then compared to the initial measurement, indicating a gain or loss of joint range of motion. Typical goniometers of this character are illustrated in U.S. Pat. Nos. 1,590,499 and 3,270,420. More complex goniometers have been provided in recent years including automated readout functions and complex arrangement for securing the devices to various body parts, see, e.g., U.S. Pat. Nos. 4,306,571, 4,436,099, 5,263,492, and 5,792,077. Additionally, specialized goniometers designed only for particular body parts such as ankles have also been provided, such as that depicted in U.S. Pat. No. 4,771,548. 
         [0005]    Gravity-operated liquid bubble devices have also been used to measure range of motion of wrist rotation and the like, where indicating arm measurements are not feasible. However, over time these devices tend to lose their liquid owing to leakage, and become inoperative. 
         [0006]    Despite the plethora of prior goniometers, a number of significant problems remain. One such difficulty is that a therapist must have and maintain a variety of different goniometers useful for range of motion measurements of various different body parts. This creates storage and handling problems, particularly if the therapist travels to the homes of patients. Additionally, the simple dual-arm goniometers require two-handed use. That is to say, the therapist must grasp the two arms in his or her hands, and move the arms into the correct alignment with the appropriate body parts. This means that the therapist does not have a free hand to assist the patient, which is sometimes necessary with elderly or burn patients. As such, range of motion measurements may require the services of two therapists. Moreover, such two-handed operation means that the therapist does not have a free hand to record range of motion results. Again, this materially increases the complexity and cost associated with range of motion measurements. 
         [0007]    There is accordingly, a real and unsatisfied need in the art for improved goniometers having essentially universal applicability and capable of one-handed use by a therapist. 
       SUMMARY OF THE INVENTION 
       [0008]    The present invention overcomes the problems outlined above and provides a multiple-use goniometer comprising a handle and an angle-indicating assembly operatively coupled with and supported by the handle, the assembly including a pair of elongated, angle-indicating arms pivotal relative to each other and selectively moveable to establish different angles between the arms. Pivot structure operatively couples the handle and the arms, preferably through a common pivot axis. 
         [0009]    The preferred goniometers of the inventions include enlarged inner and outer bases each supporting an elongated arm component. The bases are pivotally coupled together by the pivot structure, and a generally circular and in alignment with each other. In order to provide one-handed operation, a series of thumb movement surfaces are provided on the outer base. In this fashion, a therapist holding the goniometer by the handle can use his or her thumb to rotate the outer base and the associated arm. In preferred forms, the thumb movement surfaces comprise a series of openings provided in the outer base, but in alternate forms these surfaces can be recesses or frictional contact areas. The outer base and arms are preferably provided with angular and distance scales, respectively. 
         [0010]    The goniometers of the invention also preferably have a separate, gravity-operated angular measurement device which can be used independently of the angle-indicating arms. Such a device may be mounted on the outer base of the goniometer and include a circular track having a ball seated therein. Upon rotation of the goniometer, the ball moves underneath the influence of gravity to provide a range of motion measurement. Such is measured by the angle subtended by the ball upon rotation of the goniometer. 
         [0011]    In another aspect of the invention, a goniometer is provided having an angle indicating assembly including a pair of relatively shiftable angle-indicating arms, each of the arms supported by an enlarged base, with the bases being in substantial alignment to present an outer perimeter. The goniometer also has a footed, auxiliary base operatively coupled with the assembly and shiftable between a retracted position within the perimeter defined by the bases, and an extended, use position wherein at least a part of the auxiliary base extends beyond the perimeter. The auxiliary base may be used in conjunction with the gravity-operated portion of the goniometer. Typically, the base feet are extended and placed upon the spine, neck or a mobile body part of the patient. The patient then moves appropriately, and a gravity-induced measurement is taken. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is a front view of a preferred goniometer in accordance with the invention; 
           [0013]      FIG. 2  is a rear view of the goniometer of  FIG. 1 , showing the auxiliary base of the goniometer in its retracted position in full lines, and its extended, use position in phantom; 
           [0014]      FIG. 3  is a front view similar to that of  FIG. 1 , but showing the angle indicating arms of the goniometer in an aligned, overlapped relationship and in registry with the handle; 
           [0015]      FIG. 4  is an exploded perspective view of the preferred goniometer, from the front of the goniometer; 
           [0016]      FIG. 5  is an exploded perspective view of the preferred goniometer, from the rear of the goniometer; 
           [0017]      FIG. 6  is a horizontal sectional view taken along lines  6 - 6  of  FIG. 3 ; 
           [0018]      FIG. 7  is a vertical sectional view taken along lines  7 - 7  of  FIG. 3 ; 
           [0019]      FIG. 8  is a schematic view illustrating use of the goniometer of the invention in a range of motion measurement at an elbow joint; 
           [0020]      FIG. 9  is a schematic view illustrating use of the goniometer with the auxiliary base extended and placed on the spine of a patient; 
           [0021]      FIG. 10  is a schematic view illustrating use of the device measuring wrist rotation, with a patient grasping the handle of the goniometer; 
           [0022]      FIG. 11  is a schematic view similar to that of  FIG. 10 , but showing the device upon wrist rotation by the patient; 
           [0023]      FIG. 12  is a schematic view illustrating placement of the goniometer adjacent the head and neck regions of a patient, for measuring upper cervical range of motion; 
           [0024]      FIG. 13  is a schematic view similar to that of  FIG. 12 , but depicting the goniometer in its measurement position upon head movement by the patient; 
           [0025]      FIG. 14  is a schematic view illustrating initial placement of the goniometer for measurement of cervical lateral flexion; and 
           [0026]      FIG. 15  is a view similar to that of  FIG. 1 , but illustrating placement of the goniometer after the patient&#39;s cervical lateral motion, in order to determine range of such motion. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0027]    Turning now to the drawings, a preferred multiple-use goniometer  20  is illustrated in  FIGS. 1 and 2  and broadly includes a handle  22  operatively coupled with and supporting an angle-indicating assembly  24 , as well as a selectively useable auxiliary base  25 . The assembly  24  includes a pair of elongated, angle-indicating, outer and inner arms  26  and  28 , each supported by an enlarged, substantially circular, outer and inner base  30  and  32 . The handle  22  and bases  30 ,  32  are interconnected by means of a pivot screw assembly  34 . Goniometer  20  is designed to permit efficient range of motion measurements at various locations on a human patient. 
         [0028]    In more detail, the handle  22  is formed of ridged synthetic resin material and has a lower grasping portion  36  and an upper connection portion  38 . The later has a bore  40  as well as a pair of elongated, side marginal track recesses  42  and  44  terminating in upper and lower locking detents  46 ,  48  which are important for purposes to be described. It will also be observed that the portion  38  has an outwardly extending locking projection  50  on the same face thereof as the track recesses  42 ,  44  and detents  46 ,  48  (see  FIG. 4 ). 
         [0029]    The outer arm  26  is also integrally formed of synthetic resin material and includes circular outer base  30  as well as an elongated arm component  52 . The base  30  has an angular scale  54  provided on the outer face thereof, and also has a central bore  55  and a series of circumferentially spaced apart thumb movement openings  56 . As best seen in  FIG. 5 , the face of base  30  remote from the scale  54  has a locking nib  58 . The arm component  52  is provided with English and metric distance scales  60  on the outer face thereof. 
         [0030]    The inner arm  28  is also integrally formed of synthetic resin material having the inner base  32  as well as projecting arm component  62 . The base  32  has a central bore  64  as well as a plurality of circumferentially spaced apart nib-receiving recesses  66  formed on the outer face thereof. The opposed rearward face ( FIG. 5 ) also has a plurality of circumferentially spaced apart, circular locking recesses  67 . Again, the arm component  62  has English and metric distance scales  68  thereon. 
         [0031]    The overall angle-indicating assembly  24  further includes a disk-like measurement device  70  having a central bore  71 , a transparent forward face  72  with a rearward face  74  provided with a circular, peripheral track  76 . The track  76  receives a freely moveable ball  78  therein. The forward face  72  has an angular scale  80 , as well as a directional arrow  82 . The position of ball  78  within track  76  is visible through the forward transparent face  72 . 
         [0032]    The pivot screw assembly  34  comprises a headed pivot screw  84 , resilient washer  86 , acorn nut  88 . The assembly  34  is used to connect all of the parts making up goniometer  20 . 
         [0033]    The auxiliary base  25  includes an uppermost segment  90  together with a pair of depending, spaced-apart connection legs  92 ,  94 . The legs  92 ,  94  have lowermost, inwardly extending locking projections  96 . 
         [0034]    The goniometer  20  is assembled by placing the bases outer and inner  30  and  32  in face-to-face adjacency, i.e., with the rear face of outer base  30  having nib  58  in face-to-face contact with the forward face of inner base  32  having the recesses  66 . The bases  30 ,  32  are essentially congruent so that the bores  55  and  64  thereof are registry, with the bases cooperatively defining a common outer circular periphery or perimeter  98 . Next, the device  70  with ball  78  seated within track  76  is placed against the forward face of outer base  30 , such that the bore  71  aligns with bores  55  and  64 . The handle  22  and auxiliary base  25  are next interfitted by placement of the leg projections  96  within the detents  48 , and this combined structure is positioned in face-to-face contact with the rear face of inner base  32  in an orientation such that the locking projection  50  seats within one of the recesses  67 , and the bore  40  aligns with the bores  64 ,  55 , and  71 . It will be seen that the recesses  42 ,  44  and detents  46 ,  48  are adjacent the face of base  32 , thus trapping the auxiliary base  25  against the face of base  32 . At this point the screw  82  is inserted through the bores  40 ,  64 ,  55  and  71 , such that the threaded outer end thereof projects slightly beyond the face  72  of device  70 . The washer  86  and acorn nut  88  are then installed in order to complete the interconnection between handle  22  and assembly  24 . In this respect, the resilient nature of washer  86  creates a slight loading to bias together the respective locking structures between the bases  30  and  32  and between handle  22  and base  32 . 
         [0035]    As explained above, the goniometer  20  is designed to facilitate range of motion measurements at various locations on a patient&#39;s body. A number of these possible uses are depicted in  FIGS. 8-13 . It should be understood, however, that these illustrated uses are exemplary only, and that skilled artisans will readily appreciate that the goniometer has a large number of uses not specifically depicted. 
         [0036]    The goniometer  20  is most commonly used by a therapist who holds the device by grasping portion  36  of handle  22  and placing the aligned base portions  30 ,  32  substantially at a selected joint (e.g., knee, elbow, shoulder). The inner arm component  62  is then shifted into alignment with one of the joint-forming body parts, by grasping the component  62  and rotating it to the desired position. This involves overcoming the locking bias between the handle  22  and inner base  32 , and rotation of component  62  until the handle projection  50  comes into locking engagement with the appropriate recess  67  at the selected location. Next, the base  30  and arm component  52  are adjusted to align the latter with the other joint-forming body part. This is accomplished by the therapist, using his or her thumb to engage the respective thumb movement openings  56  provided in base  30 , in order to rotate the body  30  and arm  52  to the proper position. Again, such rotational movement overcomes the resilient locking bias between nib  58  and recesses  66  until the adjusted arm position is reached. In this position, the base  30  is again locked relative to base  32  because of the locking action afforded by the nib  58  and recesses  66 . 
         [0037]    Referring next to  FIG. 8 , the goniometer  20  is illustrated in a range of motion measurement at the elbow region of a patient. In this use, the inner and outer base portions  30 ,  32  are located essentially at the patient&#39;s elbow, with the arm components  52  and  62  extending along the forearm and upper arm of the patient as shown. The therapist would hold the handle  22  to support the goniometer  20 , and initially position component  62  along the patient&#39;s upper arm. The therapist would then use his or her thumb to rotate the outer base  30  as described previously until the component  52  generally aligns with the patient&#39;s forearm. Upon patient movement, the arm  52  would be moved as described, giving the desired range of motion measurement. 
         [0038]    In certain instances the arm components  52  and  62  are not useful for range of motion measurements, and instead use is made of the device  70  secured to the bases  30 ,  32 . The body  70  in effect is a gravity-induced angular measurement device which is independent of the arm components  52 ,  62 . In the use of the body  70 , the arm components  52  and  62  are rotated to a position in essentially complete alignment with handle  22  as best seen in  FIGS. 9-11 . In one use shown in  FIG. 9 , trunk/back movement is measured through use of base  25 . Thus, the auxiliary base  25  is moved to its extended position such that the segment  90  thereof extends beyond the perimeter  98  defined by the bases  30 ,  32 , with the body locked in place owing to the interfit between locking detents  46  and the leg projections  96 . The extended segment  90  is then placed at an appropriate position on the patient&#39;s trunk/back, and the device  70  is rotated to a point where track ball  78  falls to a zero position on the adjacent angular scale  80 . The patient then moves his trunk/back and the range of motion is ascertained by a comparison between the initial location of ball  78  and the location thereof after the patient movement. 
         [0039]    Another use of device  70  is illustrated in  FIGS. 10 and 11 . In this situation the patient grasps the aligned handle  22  and components  52  and  62  and holds the goniometer upright as depicted in  FIG. 10 . The position of ball  78  is set to zero by rotation of device  70 . Next the patient rotates his wrist in either direction to the full extent of which he is capable. At this extreme position the location of ball  78  is noted, and this is compared with the initial zero position. In this manner, the range of wrist rotation can be readily ascertained. 
         [0040]      FIGS. 12 and 13  illustrate a further use of goniometer  20  in the context of cervical range of motion. The therapist grasping goniometer  20  at handle section  36  moves both of the components  52 ,  62  into a substantially vertical orientation. This may be accomplished by initially locating the component  62  in this location and then moving the outer base  30  and component  52  into alignment with the base  32  and component  52 . In any event, the patient then moves his head rearwardly to the fullest extent of which he is capable, and the therapist may then move the goniometer arm components  52 ,  62  to measure this range of motion. 
         [0041]      FIG. 14  illustrates use of goniometer  20  for the measurement of cervical lateral flexion. In this use, the goniometer  20  is centered at the patient&#39;s nose, as shown in  FIG. 14 . Thereafter, the patient bends his head laterally to the maximum extent ( FIG. 15 ), and the therapist moves the arm  52  as shown to provide a range of motion measurement. 
         [0042]    Although the exemplified uses of goniometer  20  have been explained in terms of common therapist manipulations, it will be appreciated that a given user may elect to deploy and use goniometer  20  in ways different than those explained. For example, the device  70  can be used in the lateral cervical flexion range of motion measurement of  FIGS. 14-15 . 
         [0043]    The goniometer  20  posses a number of advantages not available in conventional units. Foremost among these are the multiple ways the goniometer may be used, thus allowing a therapist to reduce the equipment needed for therapy sessions. Also, owing to the one-handed operation of goniometer  20 , the therapist may better assist patients as needed and/or record results, thus eliminating the need for a second therapist or assistant. In addition, the various scales provided on the base  30 , device  70 , and arms  52 ,  62  may be brightly and/or differently colored to give maximum contrast and enhanced readability.