This is an automobile no-fault case. Plaintiffs appeal from a grant of summary judgment in favor of the defendants. The background facts are fully set forth in the dissenting opinion.
A motion for summary judgment which is based on GCR 1963, 117.2(3) is designed to test whether there is factual support for a claim. Crowther v Ross Chemical & Manufacturing Co, 42 Mich App 426; 202 NW2d 577 (1972).
When passing upon a motion under this subrule, the court must consider the pleadings, affidavits, depositions, admissions and other documentary evidence then available to it. Rizzo v Kretschmer, 389 Mich 363; 207 NW2d 316 (1973). Before the judgment may properly be granted, the court must be satisfied that it is impossible for the claim asserted to be supported by evidence at trial. The motion has the limited function of determining whether a material issue of fact exists. The trial court must carefully avoid making a finding of fact under the guise of determining that no issue of material fact exists. Partrich v Muscat, 84 Mich App 724, 730-731; 270 NW2d 506 (1978).
The defendants contend that there was no issue as to a material fact since the injuries claimed did not constitute "serious impairment of body function” so as to meet the threshold tort requirements of the no-fault act. MCL 500.3135(1); MSA 24.13135(1).
The question of whether a particular impairment satisfies the threshold requirement of the no-*171fault act for serious impairment of body function is not always a question for the trier of fact. There are cases in which the trial court can rule, as a matter of law, that a plaintiffs injury is so minor that it fails to reach the threshold of a serious impairment. Cassidy v McGovern, 86 Mich App 321, 325-326; 272 NW2d 644 (1978), Vitale v Danylak, 74 Mich App 615, 619; 254 NW2d 593 (1977), lv den 403 Mich 848 (1978), McKendrick v Petrucci, 71 Mich App 200; 247 NW2d 349 (1976). The question of serious impairment is one of law where it can be said with certainty that no reasonable jury could view a plaintiff’s impairment as serious. Such question must be approached on a case-by-case basis. Harris v McVickers, 88 Mich App 508; 276 NW2d 629 (1979).
The no-fault statute’s elimination of tort liability for noneconomic damages, except where the enumerated conditions result, is inherently directed toward a reduction in the number of litigated suits. Vitale, supra, at 619. With this policy objective in mind, we must examine the facts with respect to plaintiffs injuries in order to determine whether a reasonable jury could view such injuries as constituting a serious impairment of body function.
At the time of the accident, plaintiff told the police that his arms and wrists had been injured. Plaintiff declined to go to the hospital at that time. Furthermore, plaintiff stated that he never visited a hospital in connection with the injuries in question. Approximately four weeks later, in November, 1973, the plaintiff visited and was treated by Dr. David Eisman, a chiropractor. Plaintiff was given a heat treatment and medication. He thereafter visited Dr. Eisman three times at intervals of three to four weeks. Plaintiff did not visit Dr. *172Eisman or any other doctor after January 16, 1974.
Although fully cognizant of the fact that courts are very liberal in finding that a genuine issue of fact does exist so as to preclude summary judgment in order not to infringe on a party’s right to trial, Bob v Holmes, 78 Mich App 205; 259 NW2d 427 (1977), we find that nothing in the record discloses that the plaintiff suffered any impairment which reasonable persons could view as serious. The degree of injury in this case is insufficient to meet the minimum threshold requirement.
We arrive at this conclusion notwithstanding the affidavit of plaintiff’s doctor which opined to the contrary. The affidavit is simply one piece of evidence which must be considered in determining whether a material issue of fact exists. Rizzo v Kretschmer, supra. We are disinclined to hold that a doctor’s affidavit which opines that a plaintiff has suffered a serious impairment of body function creates a genuine issue of material fact, when an objective consideration of all the available evidence requires the opposite conclusion. The soundness of the doctor’s opinion is always open to question.
The lower court’s determination that there existed no issue as to a material fact since the injuries claimed did not constitute a serious impairment of body function was without error.
Plaintiffs’ second claim of error represents a challenge to the affidavit defendants offered in support of their summary judgment motion.
Plaintiffs contend that the trial court erred in granting summary judgment in the defendants’ favor because the affidavit in support of the motion did not aver that the affiant, if sworn as a *173witness, could testify competently to the facts contained therein.
A review of the record discloses that the affidavit in question was signed by defense counsel and merely states that the contents of the motion and the brief in support thereof "are true and accurate to the best of the deponent’s [sic] present information and knowledge”. Furthermore, no pleadings were ever filed which were sworn to by any person with personal knowledge of the facts set forth therein.
At this point, it should be noted that the affidavit states it is made upon defense counsel’s information and knowledge. The facts contained in the motion and the brief in support thereof relate to the extent of the medical treatment received by the plaintiff as a result of the accident. It is not contended that defense counsel could have testified upon personal knowledge of the facts contained, by reference, in his affidavit. In fact, no averment that he could so testify was made in the affidavit. There being an absence of personal knowledge on the part of the affiant, the affidavit is properly treated as one made upon information and belief.
A motion for summary judgment made pursuant to GCR 1963, 117.2(3) "shall be supported by affidavits”. GCR 1963, 117.3. Such affidavits must be on "personal knowledge” and "show affirmatively that the affiant, if sworn as a witness, can testify competently to the facts contained therein”. GCR 1963, 116.4. Durant v Stahlin, 375 Mich 628, 640; 135 NW2d 392 (1965), 1 Honigman & Hawkins, Michigan Court Rules Annotated (2d ed), 1978 Supp, pp 128-129.
Since the supporting affidavit must be based upon the personal knowledge of the affiant, affidavits that allegations are true to the best of the *174affiant’s knowledge and belief are generally insufficient. Jones v Shek, 48 Mich App 530, 532-533; 210 NW2d 808 (1973), Sun Insurance Office, Limited v Keller, 46 Mich App 761; 208 NW2d 525 (1973), Huron School Dist v Huron Twp, 42 Mich App 590, 592-593; 202 NW2d 491 (1972), lv den 388 Mich 789 (1972), 73 Am Jur 2d, Summary Judgment, § 17, p 740. As a result of the insufficiency, the above cited cases held that the motion for summary judgment was never properly before the trial court. The granting of the motion was deemed reversible error.
The same result is not mandated here. In a summary judgment proceeding, an affidavit is employed as a voluntary statement made ex parte. 3 Am Jur 2d, Affidavits, § 1, p 380. The function of an affidavit by the defendant is to establish affirmatively that there is no basis in fact to support plaintiffs claim. To that end, the defendant must come forward with some evidentiary proof—some statement of specific fact. Durant v Stahlin, supra, Doornbos v Nordman, 26 Mich App 278, 281; 182 NW2d 362 (1970). In the present case, the specific evidential facts (see Simerka v Pridemore, 380 Mich 250, 275; 156 NW2d 509 [1968]) concerning the nature of plaintiffs injuries and treatment were within the personal knowledge of only the plaintiff and Dr. Eisman. It is unlikely that either of them would have provided the defendants with a voluntary statement and affidavit.
Under such circumstance, the trial court has the authority to excuse the defendant from presenting the material facts in the affidavit. GCR 1963, 116.6. The affidavit is then supplemented by depositions or answers to interrogatories. Although the lower court did not expressly rely on this court rule in granting the defendants’ motion, the avail*175ability of the rule as an exception to the affidavit requirements of GCR 1963, 116.4 prevents the insufficiency of the defendants’ affidavit from rendering the grant of summary judgment reversibly erroneous.
Affirmed.
R. B. Burns, J., concurred.